CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62/162,720, filed on May 16, 2015, the content of which is hereby incorporated by reference in its entirety for all purposes.

SUBMISSION OF SEQUENCE LISTING ON ASCII TEXT FILE

[0002] The content of the following submission on ASCII text file is incorporated herein by reference in its entirety: a computer readable form (CRF) of the Sequence Listing (file name: 159792013440SEQLIST.TXT, date recorded: April 14, 2016, size: 49 KB).

FIELD OF THE INVENTION

[0003] The present invention relates to methods for treating a disease or disorder associated with a deep intronic mutation using an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system, as well as compositions, kits, and viral particles related thereto.

BACKGROUND OF INVENTION

[0004] Mutations in non-coding sequences such as introns have been implicated in a wide range of diseases. The human genome contains a higher proportion of longer introns than other organisms such as worms and flies; greater than 90% of human introns are more than 100 nucleotides in length, with more than one-third of all introns being 2,000 nucleotides or longer (Molecular Biology of the Cell, 6 ^th ed. (Alberts, B. et al. eds., 2014). In addition, deep intronic mutations have been identified as an important and potentially ignored cause of human disease, with much of the effort in identifying disease-linked mutations focused on coding sequence (Homolova, K. et al. (2010) Hum. Mutat. 31:437-444). Due to the complexity of mRNA splicing in humans, these deep intronic mutations can potentially cause a variety of pathological conditions due to mechanisms including, inter alia, mRNA destabilization, degradation, and mis-splicing (e.g., creating a cryptic splice site). Indeed, some have estimated that up to 5% of Mendelian diseases in humans may be associated with a deep intronic mutation (Cooper, D.N. et al. (2010) Hum. Mutat. 31:631-655).

[0005] As an illustrative example of a disorder that, in some cases, has been linked to a deep intronic mutation, Leber congenital amaurosis (LCA) is the most severe form of inherited retinal dystrophy with onset of symptoms in the first year of life (Leber, T.K.G.v. (1869) Graefe ' s Archive for Clinical and Experimental Ophthalmology 15: 1-25). Visual acuity in LCA patients is rarely better than 20/400 (Cremers, F.P. et al. (2002) Human molecular genetics 11: 1169-1176). LCA affects approximately 1 per 30,000 individuals in the general population and accounts for 5% of all inherited retinal dystrophies (Koenekoop, R.K. (2004) Survey of ophthalmology 49:379-398). The most frequent genetic cause of LCA, accounting for approximately 15% of all LCA cases in European countries and in the United States, is a deep-intronic mutation c.2991+1655A>G in the intron 26 of CEP290 gene, which generates a cryptic splice donor site resulting in the inclusion of an aberrant exon containing a premature stop codon (p.C998X) to CEP290 mRNA (den Hollander, A.I. et al. (2006) Am. J. Hum. Genet. 79:556-561; Perrault, I. et al. (2007) Hum. Mutat. 28:416; Stone, E.M. (2007) Am. J. Ophthalmol. 144:791-811; Wiszniewski, W. et al. (2011) Hum. Genet. 129:319-327). The LCA disease caused by CEP290 mutation is known as LCA10. Alternative splicing of the cryptic exon into CEP290 mRNA occurs in some, but not all, mRNA transcripts in the homozygous affected individuals (den Hollander, A.I. et al. (2006) Am. J. Hum. Genet. 79:556-561), stressing the hypomorphic nature of this intronic mutation.

[0006] The human CEP290 gene encompasses 54 exons that encode a 2479 amino acid protein. CEP290 is a centrosomal protein that plays an important role in both cilium assembly and ciliary protein trafficking (Barbelanne, M. et al. (2013) Hum. Mol. Genet. 22:2482-2494; Craige, B. et al. (2010) J. Cell Biol. 190:927-940). In photoreceptors, the retinal cells most affected by CEP290 mutations, CEP290 localizes to the connecting cilium (Chang, B. et al. (2006) Hum. Mol. Genet. 15: 1847-1857), which connects the inner and the outer segment of photoreceptors.

[0007] Currently there is no cure for CEP290 mutation-caused LCA. The two preclinical approaches for addressing this disease are gene augmentation and antisense

oligonucleotides (AONs). The size of human CEP290 complementary DNA (cDNA) exceeds the cargo size (-4.8 kb) of recombinant adeno-associated viruses (rAAVs). The lentiviral vector system can accommodate the full-length CEP290 cDNA; however, it may not be able to precisely control the expression level of CEP290. Previous reports have demonstrated that photoreceptors are sensitive to the level of transgene expression, and overexpression of CEP290 is cytotoxic (Burnight, E.R. et al. (2014) Gene Ther. 21:662- 672; Tan, E. et al. (2001) Invest. Ophthalmol. Vis. Sci. 42:589-600). An alternative strategy is to use AONs to interfere with the aberrant splicing of CEP290 (Collin, R.W. et al. (2012) Mol. Ther. Nucleic Acids l:el4; Gerard, X. et al. (2012) Mol. Ther. Nucleic Acids l:e29). However, this approach requires weekly or monthly subretinal injections for years by a retinal specialist.

[0008] Accordingly, there is an urgent need for improved therapeutic approaches for treating disorders linked to deep intronic mutations, such as CEP290 mutation-caused LCA10.

BRIEF SUMMARY OF THE INVENTION

[0009] The invention provides compositions for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprising an engineered, non- naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats

(CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation. In some embodiments, the invention provides compositions for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprising nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation. In some embodiments, the disease or disorder associated with a deep intronic mutation is afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta- thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute

myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone

insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi-minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X- linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some

embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 1.

[0010] In some aspects, the invention provides compositions for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising nucleic acid encoding an engineered, non-naturally occurring Clustered

Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the invention provides compositions for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR- Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2.

[0011] In some embodiments of the above embodiments, the ocular disease is Leber congenital amaurosis. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0012] In some embodiments of the above embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site in the gene.

[0013] In some embodiments of the above embodiments, the Cas protein is a Cas9 protein. In some embodiments, the Cas 9 protein is a Streptococcus pyogenes Cas9 protein (SEQ ID NO:40), a Staphylococcus aureus Cas9 protein (SEQ ID NO: 55), a Streptococcus thermophilus Cas9 protein, a Neisseria meningitidis Cas9 protein, or a Treponema denticola Cas9 protein. In some embodiments, the Cas9 is codon optimized for expression in a eukaryotic cell. In some embodiments, the eukaryotic cell is a mammalian cell. In some embodiments, the eukaryotic cell is a human cell.

[0014] In some embodiments of the above embodiments, the CRISPR-Cas system further comprises one or more nuclear localization signal(s) (NLS(s)). In some

embodiments, the Cas protein comprises one or more NLS. In some embodiments, the NLS is a C-terminal sequence in the SV40 Large T-antigen. In some embodiments, the NLS comprises the sequence PKKKRKV (SEQ ID NO:26) or PKKKRKVEDPKKKRKVD (SEQ ID NO:27).

[0015] In some embodiments of the above embodiments, the first guide RNA and/or the second guide RNA comprise are fused to a trans-activating cr (tracr) sequence. In some embodiments, the tracr sequence comprises the nucleotide sequence encoded by SEQ ID NO:25.

[0016] In some embodiments of the above embodiments, the CRISPR-Cas system {e.g., the first guide RNA, the second guide RNA and the Cas protein) is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid and/or the protein.

[0017] In some embodiments of the above embodiments, nucleic acid encoding the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the nucleic acid encoding the first guide RNA, the second guide RNA and/or the Cas protein are operably linked to one or more regulatory control elements. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. In some embodiments, the RNA polymerase III promoter is a U6, a 7SK or an HI promoter. In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. In some embodiments, the RNA polymerase II promoter is a cytomegalovirus (CMV) immediate early promoter, a minimal promoter fragment derived from the CMV promoter (minCMV promoter), a RSV LTR, a MoMLV LTR, a phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter, a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), a E2F promoter, a EFla promoter, a telomerase (hTERT) promoter, a cytomegalovirus enhancer/chicken beta- actin/Rabbit β-globin promoter (CAG) promoter, a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RPl) promoter, or an interphotoreceptor retinoid-binding protein gene (IRBP) promoter.

[0018] In some embodiments of the above embodiments, the nucleic acid encoding one or more of the first guide RNA, the second guide RNA or the Cas protein are located on the same or different vectors of the system. In some embodiments, the vector is a plasmid. In some embodiments, the vector is complexed to a delivery system. In some embodiments, the vector is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid.

[0019] In some embodiments of the above embodiments, the vector is a recombinant adeno-associated virus (rAAV) vector, a recombinant adenoviral vector, a recombinant lentiviral vector or a recombinant herpes simplex virus (HSV) vector. In some

embodiments, the vector is a recombinant adenoviral vector. In some embodiments, the recombinant adenoviral vector is derived from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenoviral vector is derived from adenovirus serotype 2 or a variant of adenoviral serotype 5.

[0020] In some embodiments, the vector is a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral vector is derived from a lentivirus pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114, or variants therein.

[0021] In some embodiments, the vector is an rHSV vector. In some embodiments, the rHSV vector is derived from rHSV-1 or rHSV-2.

[0022] In some embodiments, the vector is a recombinant AAV (rAAV) vector. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by one or more AAV inverted terminal repeat (ITR) sequences. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by two AAV ITRs. In some embodiments, the AAV ITRs are AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV capsid serotype ITRs. In some embodiments, the AAV ITRs are AAV2 ITRs. In some embodiments, the vector is a self-complementary vector.

[0023] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant adenovirus particle encapsidating a recombinant adenoviral vector. In some embodiments, the recombinant adenovirus particle comprises a capsid from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenovirus particle comprises an adenovirus serotype 2 capsid or a variant of an adenoviral serotype 5 capsid.

[0024] In some embodiments, the viral particle is a recombinant lentiviral particle encapsidating a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral particle comprises a capsid pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114 or variants therein.

[0025] In some embodiments, the viral particle is a recombinant HSV particle

encapsidating a recombinant HSV vector. In some embodiments, the recombinant HSV particle is an rHSV-1 particle or an rHSV-2 viral particle.

[0026] In some embodiments, the viral particle is a recombinant AAV viral particle comprising a recombinant AAV vector. In some embodiments, the recombinant AAV viral particle comprises an AAV serotype capsid from Clades A-F. In some embodiments, the AAV viral particle comprises an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV2/2-7m8, AAV DJ, AAV2 N587A, AAV2 E548A, AAV2 N708A, AAV V708K, a goat AAV, AAV1/AAV2 chimeric, bovine AAV, or mouse AAV capsid rAAV2/HBoVl serotype capsid. In some embodiments, the ITR and the capsid of the rAAV viral particle are derived from the same AAV serotype. In some embodiments, the ITR and the capsid of the rAAV viral particles are derived from different AAV serotypes. In some embodiments, the recombinant AAV viral particle comprises an AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid. In some embodiments, the AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid comprises a tyrosine mutation or a heparan binding mutation. In some embodiments, the rAAV vector comprises AAV2 ITRs.

[0027] In some aspects the invention provides methods for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprising

administering to the individual a therapeutically effective amount of a composition comprising an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments the invention provides methods for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprising administering to the individual a

therapeutically effective amount of a composition comprising nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the disease or disorder associated with a deep intronic mutation is afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta-thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi- minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X-linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 1.

[0028] In aspects, the invention provides methods for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising administering to the individual a therapeutically effective amount of a composition comprising an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation. In some embodiments the invention provides methods for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising administering to the individual a therapeutically effective amount of a composition comprising a nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation. In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some

embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2.

[0029] In some embodiments of the above methods, the individual is a mammal. In some embodiments, the mammal is a human. In some embodiments, the composition is administered to the eye of the individual. In some embodiments, the administration is subretinal or intravitreal.

[0030] In some embodiments of the above methods, the ocular disease is Leber congenital amaurosis. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0031] In some embodiments of the above methods, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100- 1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site in the gene.

[0032] In some embodiments of the above methods, the Cas protein is a Cas9 protein. In some embodiments, the Cas 9 protein is a Streptococcus pyogenes Cas9 protein, a

Staphylococcus aureus Cas9 protein, a Streptococcus thermophilus Cas9 protein, a

Neisseria meningitidis Cas9 protein, or a Treponema denticola Cas9 protein. In some embodiments, the Cas9 is codon optimized for expression in a eukaryotic cell. In some embodiments, the eukaryotic cell is a mammalian cell. In some embodiments, the eukaryotic cell is a human cell.

[0033] In some embodiments of the above methods, the CRISPR-Cas system further comprises one or more nuclear localization signal(s) (NLS(s)). In some embodiments, the Cas protein comprises one or more NLS. In some embodiments, the NLS is a C-terminal sequence in the SV40 Large T-antigen. In some embodiments, the NLS comprises the sequence PKKKRKV (SEQ ID NO:26) or PKKKRKVEDPKKKRKVD (SEQ ID NO:27).

[0034] In some embodiments of the above methods, the first guide RNA and/or the second guide RNA comprise are fused to a trans-activating cr (tracr) sequence. In some embodiments, the tracr sequence comprises the nucleotide sequence encoded by SEQ ID NO:25.

[0035] In some embodiments of the above methods, the CRISPR-Cas system (e.g., the first guide RNA, the second guide RNA and the Cas protein) is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid and/or the protein.

[0036] In some embodiments of the above methods, nucleic acid encoding the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the nucleic acid encoding the first guide RNA, the second guide RNA and/or the Cas protein are operably linked to one or more regulatory control elements. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. In some embodiments, the RNA polymerase III promoter is a U6, a 7SK or an HI promoter. In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. In some embodiments, the RNA polymerase II promoter is a cytomegalovirus (CMV) immediate early promoter, a minimal promoter fragment derived from the CMV promoter (minCMV promoter), a RSV LTR, a MoMLV LTR, a phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter, a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), a E2F promoter, a EF1 a promoter, a telomerase (hTERT) promoter, a cytomegalovirus enhancer/chicken beta-actin/Rabbit β- globin promoter (CAG) promoter, a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RP1) promoter, or an interphotoreceptor retinoid-binding protein gene (IRBP) promoter.

[0037] In some embodiments of the above methods, the nucleic acid encoding one or more of the first guide RNA, the second guide RNA or the Cas protein are located on the same or different vectors of the system. In some embodiments, the vector is a plasmid. In some embodiments, the vector is complexed to a delivery system. In some embodiments, the vector is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid.

[0038] In some embodiments of the above embodiments, the vector is a recombinant adeno-associated virus (rAAV) vector, a recombinant adenoviral vector, a recombinant lentiviral vector or a recombinant herpes simplex virus (HSV) vector. In some

embodiments, the vector is a recombinant adenoviral vector. In some embodiments, the recombinant adenoviral vector is derived from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenoviral vector is derived from adenovirus serotype 2 or a variant of adenoviral serotype 5.

[0039] In some embodiments, the vector is a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral vector is derived from a lentivirus pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114, or variants therein. [0040] In some embodiments, the vector is an rHSV vector. In some embodiments, the rHSV vector is derived from rHSV-1 or rHSV-2.

[0041] In some embodiments, the vector is a recombinant AAV (rAAV) vector. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by one or more AAV inverted terminal repeat (ITR) sequences. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by two AAV ITRs. In some embodiments, the AAV ITRs are AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV capsid serotype ITRs. In some embodiments, the AAV ITRs are AAV2 ITRs. In some embodiments, the vector is a self-complementary vector.

[0042] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant adenovirus particle encapsidating a recombinant adenoviral vector. In some embodiments, the recombinant adenovirus particle comprises a capsid from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenovirus particle comprises an adenovirus serotype 2 capsid or a variant of an adenoviral serotype 5 capsid.

[0043] In some embodiments, the viral particle is a recombinant lentiviral particle encapsidating a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral particle comprises a capsid pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114 or variants therein.

[0044] In some embodiments, the viral particle is a recombinant HSV particle

encapsidating a recombinant HSV vector. In some embodiments, the recombinant HSV particle is an rHSV-1 particle or an rHSV-2 viral particle.

[0045] In some embodiments, the viral particle is a recombinant AAV viral particle comprising a recombinant AAV vector. In some embodiments, the recombinant AAV viral particle comprises an AAV serotype capsid from Clades A-F. In some embodiments, the AAV viral particle comprises an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV2/2-7m8, AAV DJ, AAV2 N587A, AAV2 E548A, AAV2 N708A, AAV V708K, a goat AAV, AAV1/AAV2 chimeric, bovine AAV, or mouse AAV capsid rAAV2/HBoVl serotype capsid. In some embodiments, the ITR and the capsid of the rAAV viral particle are derived from the same AAV serotype. In some embodiments, the ITR and the capsid of the rAAV viral particles are derived from different AAV serotypes. In some embodiments, the recombinant AAV viral particle comprises an AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid. In some embodiments, the AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid comprises a tyrosine mutation or a heparan binding mutation. In some embodiments, the rAAV vector comprises AAV2 ITRs.

[0046] In some embodiments of the above methods, the composition is a pharmaceutical composition.

[0047] In some aspects, the invention provides the use of a composition of any one of the above embodiments for treating a disorder associated with a deep intronic mutation in a gene of an individual. In some aspects, the invention provides the use of a composition of any one of the above embodiments in the manufacture of a medicament for treating a disorder associated with a deep intronic mutation in a gene of an individual. In some embodiments, the disease or disorder associated with a deep intronic mutation is afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta-thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi- minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X-linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 1. In some embodiments, the disease or disorder associated with a deep intronic mutation is an ocular disease. In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2. In some embodiments, the individual is a mammal. In some embodiments, the mammal is a human. In some embodiments, the ocular disease is Leber congenital amaurosis.

[0048] In some embodiments of the above uses, the composition is formulated for administration to the eye of the individual. In some embodiments, the administration is formulated for subretinal or intravitreal administration.

[0049] In some embodiments of the above uses, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23. [0050] In some embodiments of the above uses, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100- 1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site.

[0051] In some aspects, the invention provides kits comprising the composition of any one of the above embodiments. In some embodiments, the kit comprises the composition of any one of the above embodiments for use in any of the methods described herein. In some embodiments, the kit further comprises instructions for use.

[0052] In some aspects, the invention provides viral particles comprising a viral vector wherein the viral vector comprises nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation in a gene of an individual, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation. In some embodiments, the deep intronic mutation in a gene of an individual is associated with afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta-thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi- minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X-linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some embodiments, the deep intronic mutation in a gene of an individual is a deep intronic mutation presented in Table 1.

[0053] In some embodiments, the viral particle is used to treat an individual with afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta-thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi- minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X-linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia.

[0054] In some aspects, the invention provides viral particles comprising a viral vector wherein the viral vector comprises nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation in a gene of an individual associated with an ocular disease or disorder, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the ocular disease or disorder is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2. In some embodiments, the viral particle is used to treat Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa.

[0055] In some embodiments, the ocular disease is Leber congenital amaurosis. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.\

[0056] In some embodiments of the above viral particles, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000

nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site in the gene.

[0057] In some embodiments of the above viral particles, the Cas protein is a Cas9 protein. In some embodiments, the Cas 9 protein is a Streptococcus pyogenes Cas9 protein, a Staphylococcus aureus Cas9 protein, a Streptococcus thermophilus Cas9 protein, a Neisseria meningitidis Cas9 protein, or a Treponema denticola Cas9 protein. In some embodiments, the Cas9 is codon optimized for expression in a eukaryotic cell. In some embodiments, the eukaryotic cell is a mammalian cell. In some embodiments, the eukaryotic cell is a human cell.

[0058] In some embodiments of the above viral particles, the CRISPR-Cas system further comprises one or more nuclear localization signal(s) (NLS(s)). In some

embodiments, the Cas protein comprises one or more NLS. In some embodiments, the NLS is a C-terminal sequence in the SV40 Large T-antigen. In some embodiments, the NLS comprises the sequence PKKKRKV (SEQ ID NO:26) or PKKKRKVEDPKKKRKVD (SEQ ID NO:27).

[0059] In some embodiments of the above viral particles, the first guide RNA and/or the second guide RNA comprise are fused to a trans-activating cr (tracr) sequence. In some embodiments, the tracr sequence comprises the nucleotide sequence encoded by SEQ ID NO:25.

[0060] In some embodiments of the above viral particles, nucleic acid encoding the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the nucleic acid encoding the first guide RNA, the second guide RNA and/or the Cas protein are operably linked to one or more regulatory control elements. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. In some embodiments, the RNA polymerase III promoter is a U6, a 7SK or an HI promoter. In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. In some embodiments, the RNA polymerase II promoter is a cytomegalovirus (CMV) immediate early promoter, a minimal promoter fragment derived from the CMV promoter (minCMV promoter), a RSV LTR, a MoMLV LTR, a phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter, a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), a E2F promoter, a EFla promoter, a telomerase (hTERT) promoter, a cytomegalovirus enhancer/chicken beta- actin/Rabbit β-globin promoter (CAG) promoter, a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RPl) promoter, or an interphotoreceptor retinoid-binding protein gene (IRBP) promoter. [0061] In some embodiments of the above viral particles, the nucleic acid encoding one or more of the first guide RNA, the second guide RNA or the Cas protein are located on the same or different vectors of the system. In some embodiments, the vector is a plasmid. In some embodiments, the vector is complexed to a delivery system. In some embodiments, the vector is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid.

[0062] In some embodiments of the above viral particles, the vector is a recombinant adeno-associated virus (rAAV) vector, a recombinant adenoviral vector, a recombinant lentiviral vector or a recombinant herpes simplex virus (HSV) vector. In some

embodiments, the vector is a recombinant adenoviral vector. In some embodiments, the recombinant adenoviral vector is derived from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7,

14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenoviral vector is derived from adenovirus serotype 2 or a variant of adenoviral serotype 5. In some embodiments, the viral particle is a recombinant adenovirus particle encapsidating a recombinant adenoviral vector. In some embodiments, the recombinant adenovirus particle comprises a capsid from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13,

15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenovirus particle comprises an adenovirus serotype 2 capsid or a variant of an adenoviral serotype 5 capsid.

[0063] In some embodiments, the vector is a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral vector is derived from a lentivirus pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114, or variants therein. In some embodiments, the viral particle is a recombinant lentiviral particle encapsidating a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral particle comprises a capsid pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114 or variants therein.

[0064] In some embodiments, the vector is an rHSV vector. In some embodiments, the rHSV vector is derived from rHSV-1 or rHSV-2. In some embodiments, the viral particle is a recombinant HSV particle encapsidating a recombinant HSV vector. In some embodiments, the recombinant HSV particle is an rHSV-1 particle or an rHSV-2 viral particle.

[0065] In some embodiments, the vector is a recombinant AAV (rAAV) vector. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by one or more AAV inverted terminal repeat (ITR) sequences. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by two AAV ITRs. In some embodiments, the AAV ITRs are AAVl, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV capsid serotype ITRs. In some embodiments, the AAV ITRs are AAV2 ITRs. In some embodiments, the vector is a self-complementary vector. In some embodiments, the viral particle is a recombinant AAV viral particle comprising a recombinant AAV vector. In some embodiments, the recombinant AAV viral particle comprises an AAV serotype capsid from Clades A-F. In some embodiments, the AAV viral particle comprises an AAVl, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV2/2-7m8, AAV DJ, AAV2 N587A, AAV2 E548A, AAV2 N708A, AAV V708K, a goat AAV, AAV1/AAV2 chimeric, bovine AAV, or mouse AAV capsid rAAV2/HBoVl serotype capsid. In some embodiments, the ITR and the capsid of the rAAV viral particle are derived from the same AAV serotype. In some embodiments, the ITR and the capsid of the rAAV viral particles are derived from different AAV serotypes. In some embodiments, the recombinant AAV viral particle comprises an AAVl, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid. In some embodiments, the AAVl, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid comprises a tyrosine mutation or a heparan binding mutation. In some embodiments, the rAAV vector comprises AAV2 ITRs. [0066] In some embodiments of the above viral particles, the viral particle is in a pharmaceutical composition.

[0067] In some aspects, the invention provides methods for generating an in vitro model of an ocular disease associated with deep intronic mutation in a gene comprising a) introducing to eukaryotic cells nucleic acid encoding a CRISPR-Cas system, wherein the CRISPR-Cas system comprises i) a single guide RNA that hybridizes to the opposite strand of the target DNA sequence of an intron in the gene, ii) a nucleotide sequence encoding a Cas protein, iii) a single- stranded oligonucleotide comprising a homology directed repair (HDR) template comprising homology arms flanking a desired intronic mutation and a protospacer adjacent motif (PAM); and b) isolating cells that comprise the mutation incorporated into gene.

[0068] In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site in the gene.

[0069] In some embodiments, the PAM comprises a mutation to avoid cleavage of the single-stranded oligonucleotide by an expressed Cas protein in the cells.

[0070] In some embodiments, the Cas protein is a Cas9 protein. In some embodiments, the Cas 9 protein is a Streptococcus pyogenes Cas9 protein, a Staphylococcus aureus Cas9 protein, a Streptococcus thermophilus Cas9 protein, a Neisseria meningitidis Cas9 protein, or a Treponema denticola Cas9 protein. In some embodiments, the Cas9 is codon optimized for expression in the eukaryotic cells. In some embodiments, the eukaryotic cells are mammalian cells. In some embodiments, the eukaryotic cells are human cells. In some embodiments, the eukaryotic cells are ocular cells. In some embodiments, the ocular cells are retinal cells.

[0071] In some embodiments, the CRISPR-Cas system further comprises one or more nuclear localization signal(s) (NLS(s)). In some embodiments, the Cas protein comprises one or more NLS. In some embodiments, the NLS is a C-terminal sequence in the SV40 Large T-antigen. In some embodiments, the NLS comprises the sequence PKKKRKV (SEQ ID NO:26) or PKKKRKVEDPKKKRKVD (SEQ ID NO:27).

[0072] In some embodiments, the first guide RNA and/or the second guide RNA comprise are fused to a trans-activating cr (tracr) sequence. In some embodiments, the tracr sequence comprises the nucleotide sequence encoded by SEQ ID NO:25.

[0073] In some embodiments, nucleic acid encoding the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the nucleic acid encoding the first guide RNA, the second guide RNA and/or the Cas protein are operably linked to one or more regulatory control elements. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. In some embodiments, the RNA polymerase III promoter is a U6, a 7SK or an HI promoter. In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. In some embodiments, the RNA polymerase II promoter is a cytomegalovirus (CMV) immediate early promoter, a minimal promoter fragment derived from the CMV promoter (minCMV promoter), a RSV LTR, a MoMLV LTR, a phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter, a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), a E2F promoter, a EF1 a promoter, a telomerase (hTERT) promoter, a cytomegalovirus enhancer/chicken beta-actin/Rabbit β- globin promoter (CAG) promoter, a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RP1) promoter, or an interphotoreceptor retinoid-binding protein gene (IRBP) promoter.

[0074] In some embodiments, the nucleic acid encoding one or more of the single guide RNA, the Cas protein, or the single-stranded oligonuleotide are located on the same or different vectors of the system.

[0075] In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X- linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2. In some embodiments, the viral particle is used to treat Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa.

[0076] In some embodiments, the ocular disease is Leber congenital amaurosis. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0077] In some aspects, the invention provides a method for cleaving a target nucleic acid in a cell comprising delivering to the cell effective amount of a composition comprising: a) a nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly

Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR- Cas) system comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking the mutation; and b) a Cas expression cassette comprising: i) a nucleotide sequence encoding a Cas protein, and ii) a first guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the first guide RNA target site; wherein the Cas protein is expressed from the Cas expression cassette; wherein the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation; and wherein the Cas protein cleaves the Cas expression cassette at the first guide RNA target site, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some aspects, the invention provides a method for treating a disease or disorder associated with a mutation in a nucleic acid of an individual comprising administering to the individual a therapeutically effective amount of a composition comprising: a) a nucleic acid encoding an engineered, non-naturally occurring Clustered

Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas)

(CRISPR-Cas) system comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking the mutation; and b) a Cas expression cassette comprising: i) a nucleotide sequence encoding a Cas protein, and ii) a first guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the first guide RNA target site; wherein the Cas protein is expressed from the Cas expression cassette; wherein the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation; and wherein the Cas protein cleaves the Cas expression cassette at the first guide RNA target site, thereby reducing expression of the

Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some aspects, the invention provides a method for treating an ocular disease or disorder associated with a mutation in a nucleic acid of an individual comprising administering to the individual a therapeutically effective amount of a composition comprising: a) a nucleic acid encoding an engineered, non-naturally occurring Clustered

Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas)

(CRISPR-Cas) system comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking the mutation; and b) a Cas expression cassette comprising: i) a nucleotide sequence encoding a Cas protein, and ii) a first guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the first guide RNA target site wherein the Cas protein is expressed from the Cas expression cassette; wherein the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation; and wherein the Cas protein cleaves the Cas expression cassette at the first guide RNA target site, thereby reducing expression of the

Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some embodiments, the Cas expression cassette further comprises: iii) a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site;wherein the Cas protein cleaves the Cas expression cassette at the first and the second guide RNA target sites, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette.

[0078] In some embodiments of the above methods, the first guide RNA hybridizes to the first guide RNA target site and the second guide RNA target site. In some embodiments, the second guide RNA hybridizes to the first guide RNA target site and the second guide RNA target site. In some embodiments, the first guide RNA hybridizes to the first guide RNA target site, and the second guide RNA hybridizes to the second guide RNA target site. In some embodiments, the Cas expression cassette further comprises further comprises a polyadenylation (polyA) sequence operably linked to the nucleotide sequence encoding the Cas protein. In some embodiments, the polyA sequence is an SV40 polyA sequence. In some embodiments, cleavage of the first or the second guide RNA target site by Cas protein interrupts the operable linkage between the nucleotide sequence encoding the Cas protein and the polyA sequence. In some embodiments, the first or the second guide RNA target site is between the nucleotide sequence encoding the Cas protein and the polyA sequence. In some embodiments, the nucleotide sequence encoding the Cas protein is operably linked to a nucleotide sequence encoding one or more nuclear localization signal(s) (NLS(s)), such that the Cas protein expressed from the Cas expression cassette is fused in-frame with the one or more NLS(s). In some embobiments, the nucleotide sequence encoding the one or more NLS(s) is between the nucleotide sequence encoding the Cas protein and a

polyadenylation (polyA) sequence. In some embodiments, the first or the second guide RNA target site is between the nucleotide sequence encoding the one or more NLS(s) and the polyA sequence. In some embodiments, the one or more NLS(s) comprises a C- terminal sequence in the SV40 Large T-antigen. In some embodiments, the one or more NLS(s) comprises the sequence PKKKRKV (SEQ ID NO:26) or

PKKKRKVEDPKKKRKVD (SEQ ID NO:27). In some embodiments, the nucleic acid encoding the CRISPR-Cas system and/or the Cas expression cassette are operably linked to one or more regulatory control elements. In some embodiments, the nucleotide sequence encoding the Cas protein is operably linked to a promoter. In some embodiments, cleavage of the first or the second guide RNA target site by the Cas protein interrupts the operable linkage between the regulatory control element and the nucleotide sequence encoding the Cas protein. In some embodiments, the first or the second guide RNA target site is between the promoter and the nucleotide sequence encoding the Cas protein. [0079] In some embodiments of the above methods, the Cas expression cassette further comprises: iii) a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site, and wherein the second guide RNA target site is adjacent to a protospacer adjacent motif (PAM) specific for the Cas protein; wherein cleavage of the first guide RNA target site by Cas protein interrupts the operable linkage between the regulatory control element and the nucleotide sequence encoding the Cas protein; wherein cleavage of the second guide RNA target site by Cas protein interrupts the operable linkage between the nucleotide sequence encoding the Cas protein and the polyA sequence; and wherein upon expression of the Cas protein and cleavage of the target DNA sequences, the Cas protein cleaves the Cas expression cassette at the first and the second guide RNA target sites, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some embodiments, the Cas expression cassette further comprises: iii) a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site; wherein the first guide RNA target site is between the nucleotide sequence encoding the Cas protein and a promoter operably linked to the nucleotide sequence encoding the Cas protein; wherein the second guide RNA target site is between the nucleotide sequence encoding the Cas protein and a polyA sequence operably linked to the nucleotide sequence encoding the Cas protein; and wherein the Cas protein cleaves the Cas expression cassette at the first and the second guide RNA target sites, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette.

[0080] In some embodiments of the above methods, the disease or disorder associated with a deep intronic mutation is afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta-thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone

insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi-minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X- linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some

embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 1.

[0081] In some aspects, the invention provides compositions for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the invention provides compositions for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR- Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2.

[0082] In some embodiments of the above embodiments, the ocular disease is Leber congenital amaurosis. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0083] In some embodiments of the above embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site in the gene.

[0084] In some embodiments of the above embodiments, the Cas protein is a Cas9 protein. In some embodiments, the Cas 9 protein is a Streptococcus pyogenes Cas9 protein (SEQ ID NO:40), a Staphylococcus aureus Cas9 protein (SEQ ID NO: 55), a Streptococcus thermophilus Cas9 protein, a Neisseria meningitidis Cas9 protein, or a Treponema denticola Cas9 protein. In some embodiments, the Cas9 is codon optimized for expression in a eukaryotic cell. In some embodiments, the eukaryotic cell is a mammalian cell. In some embodiments, the eukaryotic cell is a human cell.

[0085] In some embodiments of the above embodiments, the first guide RNA and/or the second guide RNA comprise are fused to a trans-activating cr (tracr) sequence. In some embodiments, the tracr sequence comprises the nucleotide sequence encoded by SEQ ID NO:25.

[0086] In some embodiments of the above embodiments, the CRISPR-Cas system (e.g. , the first guide RNA, the second guide RNA and the Cas protein) is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid and/or the protein.

[0087] In some embodiments of the above embodiments, nucleic acid encoding the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the nucleic acid encoding the first guide RNA, the second guide RNA and/or the Cas protein are operably linked to one or more regulatory control elements. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. In some embodiments, the RNA polymerase III promoter is a U6, a 7SK or an HI promoter. In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. In some embodiments, the RNA polymerase II promoter is a cytomegalovirus (CMV) immediate early promoter, a minimal promoter fragment derived from the CMV promoter (minCMV promoter), a RSV LTR, a MoMLV LTR, a phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter, a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), a E2F promoter, a EFla promoter, a telomerase (hTERT) promoter, a cytomegalovirus enhancer/chicken beta- actin/Rabbit β-globin promoter (CAG) promoter, a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RPl) promoter, or an interphotoreceptor retinoid-binding protein gene (IRBP) promoter.

[0088] In some embodiments of the above embodiments, the nucleic acid encoding one or more of the first guide RNA, the second guide RNA or the Cas protein are located on the same or different vectors of the system. In some embodiments, the vector is a plasmid. In some embodiments, the vector is complexed to a delivery system. In some embodiments, the vector is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid. [0089] In some embodiments of the above embodiments, the vector is a recombinant adeno-associated virus (rAAV) vector, a recombinant adenoviral vector, a recombinant lentiviral vector or a recombinant herpes simplex virus (HSV) vector. In some

embodiments, the vector is a recombinant adenoviral vector. In some embodiments, the recombinant adenoviral vector is derived from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenoviral vector is derived from adenovirus serotype 2 or a variant of adenoviral serotype 5.

[0090] In some embodiments, the vector is a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral vector is derived from a lentivirus pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114, or variants therein.

[0091] In some embodiments, the vector is an rHSV vector. In some embodiments, the rHSV vector is derived from rHSV-1 or rHSV-2.

[0092] In some embodiments, the vector is a recombinant AAV (rAAV) vector. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by one or more AAV inverted terminal repeat (ITR) sequences. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by two AAV ITRs. In some embodiments, the AAV ITRs are AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV capsid serotype ITRs. In some embodiments, the AAV ITRs are AAV2 ITRs. In some embodiments, the vector is a self-complementary vector.

[0093] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant adenovirus particle encapsidating a recombinant adenoviral vector. In some embodiments, the recombinant adenovirus particle comprises a capsid from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenovirus particle comprises an adenovirus serotype 2 capsid or a variant of an adenoviral serotype 5 capsid.

[0094] In some embodiments, the viral particle is a recombinant lentiviral particle encapsidating a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral particle comprises a capsid pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114 or variants therein.

[0095] In some embodiments, the viral particle is a recombinant HSV particle

encapsidating a recombinant HSV vector. In some embodiments, the recombinant HSV particle is an rHSV-1 particle or an rHSV-2 viral particle.

[0096] In some embodiments, the viral particle is a recombinant AAV viral particle comprising a recombinant AAV vector. In some embodiments, the recombinant AAV viral particle comprises an AAV serotype capsid from Clades A-F. In some embodiments, the AAV viral particle comprises an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV2/2-7m8, AAV DJ, AAV2 N587A, AAV2 E548A, AAV2 N708A, AAV V708K, a goat AAV, AAV1/AAV2 chimeric, bovine AAV, or mouse AAV capsid rAAV2/HBoVl serotype capsid. In some embodiments, the ITR and the capsid of the rAAV viral particle are derived from the same AAV serotype. In some embodiments, the ITR and the capsid of the rAAV viral particles are derived from different AAV serotypes. In some embodiments, the recombinant AAV viral particle comprises an AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid. In some embodiments, the AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid comprises a tyrosine mutation or a heparan binding mutation. In some embodiments, the rAAV vector comprises AAV2 ITRs.

[0097] In some aspects, the invention provides compositions for cleaving a target nucleic acid in a cell comprising: a) a nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking the mutation; and b) a Cas expression cassette comprising: i) a nucleotide sequence encoding a Cas protein, and ii) a first guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the first guide RNA target site; wherein the Cas protein is expressed from the Cas expression cassette; wherein the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation; and wherein the Cas protein cleaves the Cas expression cassette at the first guide RNA target site, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some aspects, the invention provides a compositions for treating a disease or disorder associated with a mutation in a nucleic acid of an individual comprising: a) a nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking the mutation; and b) a Cas expression cassette comprising: i) a nucleotide sequence encoding a Cas protein, and ii) a first guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the first guide RNA target site; wherein the Cas protein is expressed from the Cas expression cassette; wherein the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation; and wherein the Cas protein cleaves the Cas expression cassette at the first guide RNA target site, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some aspects, the invention provides a compositoins for treating an ocular disease or disorder associated with a mutation in a nucleic acid of an individual comprising: a) a nucleic acid encoding an engineered, non- naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats

(CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking the mutation; and b) a Cas expression cassette comprising: i) a nucleotide sequence encoding a Cas protein, and ii) a first guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the first guide RNA target site wherein the Cas protein is expressed from the Cas expression cassette; wherein the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation; and wherein the Cas protein cleaves the Cas expression cassette at the first guide RNA target site, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some embodiments, the Cas expression cassette further comprises: iii) a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site;wherein the Cas protein cleaves the Cas expression cassette at the first and the second guide RNA target sites, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette.

[0098] In some embodiments of the above compositions, the first guide RNA hybridizes to the first guide RNA target site and the second guide RNA target site. In some embodiments, the second guide RNA hybridizes to the first guide RNA target site and the second guide RNA target site. In some embodiments, the first guide RNA hybridizes to the first guide RNA target site, and the second guide RNA hybridizes to the second guide RNA target site. In some embodiments, the Cas expression cassette further comprises further comprises a polyadenylation (polyA) sequence operably linked to the nucleotide sequence encoding the Cas protein. In some embodiments, the polyA sequence is an SV40 polyA sequence. In some embodiments, cleavage of the first or the second guide RNA target site by Cas protein interrupts the operable linkage between the nucleotide sequence encoding the Cas protein and the polyA sequence. In some embodiments, the first or the second guide RNA target site is between the nucleotide sequence encoding the Cas protein and the polyA sequence. In some embodiments, the nucleotide sequence encoding the Cas protein is operably linked to a nucleotide sequence encoding one or more nuclear localization signal(s) (NLS(s)), such that the Cas protein expressed from the Cas expression cassette is fused in-frame with the one or more NLS(s). In some embobiments, the nucleotide sequence encoding the one or more NLS(s) is between the nucleotide sequence encoding the Cas protein and a polyadenylation (polyA) sequence. In some embodiments, the first or the second guide RNA target site is between the nucleotide sequence encoding the one or more NLS(s) and the polyA sequence. In some embodiments, the one or more NLS(s) comprises a C-terminal sequence in the SV40 Large T-antigen. In some embodiments, the one or more NLS(s) comprises the sequence PKKKRKV (SEQ ID NO:26) or

PKKKRKVEDPKKKRKVD (SEQ ID NO:27). In some embodiments, the nucleic acid encoding the CRISPR-Cas system and/or the Cas expression cassette are operably linked to one or more regulatory control elements. In some embodiments, the nucleotide sequence encoding the Cas protein is operably linked to a promoter. In some embodiments, cleavage of the first or the second guide RNA target site by the Cas protein interrupts the operable linkage between the regulatory control element and the nucleotide sequence encoding the Cas protein. In some embodiments, the first or the second guide RNA target site is between the promoter and the nucleotide sequence encoding the Cas protein.

[0099] In some embodiments of the above compositions, the Cas expression cassette further comprises: iii) a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site, and wherein the second guide RNA target site is adjacent to a protospacer adjacent motif (PAM) specific for the Cas protein; wherein cleavage of the first guide RNA target site by Cas protein interrupts the operable linkage between the regulatory control element and the nucleotide sequence encoding the Cas protein; wherein cleavage of the second guide RNA target site by Cas protein interrupts the operable linkage between the nucleotide sequence encoding the Cas protein and the polyA sequence; and wherein upon expression of the Cas protein and cleavage of the target DNA sequences, the Cas protein cleaves the Cas expression cassette at the first and the second guide RNA target sites, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette. In some embodiments, the Cas expression cassette further comprises: iii) a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site; wherein the first guide RNA target site is between the nucleotide sequence encoding the Cas protein and a promoter operably linked to the nucleotide sequence encoding the Cas protein; wherein the second guide RNA target site is between the nucleotide sequence encoding the Cas protein and a polyA sequence operably linked to the nucleotide sequence encoding the Cas protein; and wherein the Cas protein cleaves the Cas expression cassette at the first and the second guide RNA target sites, thereby reducing expression of the Cas protein, as compared to expression of the Cas protein prior to cleavage of the Cas expression cassette.

[0100] In some embodiments of the above compositions, the disease or disorder associated with a deep intronic mutation is afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta-thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi-minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta- aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X-linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 1.

[0101] In some aspects, the invention provides compositions for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly

Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the invention provides compositions for treating an ocular disease or disorder associated with a deep intronic mutation in a gene of an individual comprising an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system

comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of target DNA comprising the deep intronic mutation. In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2.

[0102] In some embodiments of the above compositions, the ocular disease is Leber congenital amaurosis. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In some embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the first guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some embodiments, the first guide RNA is encoded by DNA comprising the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, the second guide RNA is encoded by DNA comprising the sequence of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the CEP290 is a human CEP290. In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0103] In some embodiments of the above compositions, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides downstream of a 5' splice donor site of the gene. In some embodiments, the deep intronic mutation is located about 1-10,000 nucleotides, about 1-1000 nucleotides or about 100-1000 nucleotides upstream of a 3' splice acceptor site of the gene. In some embodiments, the deep intronic mutation introduces a splice donor site or a splice acceptor site in the gene.

[0104] In some embodiments of the above compositions, the Cas protein is a Cas9 protein. In some embodiments, the Cas 9 protein is a Streptococcus pyogenes Cas9 protein (SEQ ID NO:40), a Staphylococcus aureus Cas9 protein (SEQ ID NO: 55), a Streptococcus thermophilus Cas9 protein, a Neisseria meningitidis Cas9 protein, or a Treponema denticola Cas9 protein. In some embodiments, the Cas9 is codon optimized for expression in a eukaryotic cell. In some embodiments, the eukaryotic cell is a mammalian cell. In some embodiments, the eukaryotic cell is a human cell. [0105] In some embodiments of the above compositions, the first guide RNA and/or the second guide RNA comprise are fused to a trans-activating cr (tracr) sequence. In some embodiments, the tracr sequence comprises the nucleotide sequence encoded by SEQ ID NO:25.

[0106] In some embodiments of the above compositions, the CRISPR-Cas system (e.g. , the first guide RNA, the second guide RNA and the Cas protein) is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid and/or the protein.

[0107] In some embodiments of the above compositions, nucleic acid encoding the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the nucleic acid encoding the first guide RNA, the second guide RNA and/or the Cas protein are operably linked to one or more regulatory control elements. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. In some embodiments, the RNA polymerase III promoter is a U6, a 7SK or an HI promoter. In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. In some embodiments, the RNA polymerase II promoter is a cytomegalovirus (CMV) immediate early promoter, a minimal promoter fragment derived from the CMV promoter (minCMV promoter), a RSV LTR, a MoMLV LTR, a phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter, a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), a E2F promoter, a EF1 a promoter, a telomerase (hTERT) promoter, a cytomegalovirus enhancer/chicken beta-actin/Rabbit β- globin promoter (CAG) promoter, a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RP1) promoter, or an

interphotoreceptor retinoid-binding protein gene (IRBP) promoter.

[0108] In some embodiments of the above compositions, the nucleic acid encoding one or more of the first guide RNA, the second guide RNA or the Cas protein are located on the same or different vectors of the system. In some embodiments, the vector is a plasmid. In some embodiments, the vector is complexed to a delivery system. In some embodiments, the vector is complexed to a lipid, a cationic lipid, a liposome, a polycation or an agent that enhances the cellular uptake of nucleic acid. [0109] In some embodiments of the above compositions, the vector is a recombinant adeno-associated virus (rAAV) vector, a recombinant adenoviral vector, a recombinant lentiviral vector or a recombinant herpes simplex virus (HSV) vector. In some embodiments, the vector is a recombinant adenoviral vector. In some embodiments, the recombinant adenoviral vector is derived from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenoviral vector is derived from adenovirus serotype 2 or a variant of adenoviral serotype 5.

[0110] In some embodiments, the vector is a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral vector is derived from a lentivirus pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114, or variants therein.

[0111] In some embodiments, the vector is an rHSV vector. In some embodiments, the rHSV vector is derived from rHSV-1 or rHSV-2.

[0112] In some embodiments, the vector is a recombinant AAV (rAAV) vector. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by one or more AAV inverted terminal repeat (ITR) sequences. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by two AAV ITRs. In some embodiments, the AAV ITRs are AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV capsid serotype ITRs. In some embodiments, the AAV ITRs are AAV2 ITRs. In some embodiments, the vector is a self- complementary vector.

[0113] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant adenovirus particle encapsidating a recombinant adenoviral vector. In some embodiments, the recombinant adenovirus particle comprises a capsid from Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenovirus particle comprises an adenovirus serotype 2 capsid or a variant of an adenoviral serotype 5 capsid.

[0114] In some embodiments, the viral particle is a recombinant lentiviral particle encapsidating a recombinant lentiviral vector. In some embodiments, the recombinant lentiviral particle comprises a capsid pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD114 or variants therein.

[0115] In some embodiments, the viral particle is a recombinant HSV particle

encapsidating a recombinant HSV vector. In some embodiments, the recombinant HSV particle is an rHSV-1 particle or an rHSV-2 viral particle.

[0116] In some embodiments, the viral particle is a recombinant AAV viral particle comprising a recombinant AAV vector. In some embodiments, the recombinant AAV viral particle comprises an AAV serotype capsid from Clades A-F. In some embodiments, the AAV viral particle comprises an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV2/2-7m8, AAV DJ, AAV2 N587A, AAV2 E548A, AAV2 N708A, AAV V708K, a goat AAV, AAV1/AAV2 chimeric, bovine AAV, or mouse AAV capsid rAAV2/HBoVl serotype capsid. In some embodiments, the ITR and the capsid of the rAAV viral particle are derived from the same AAV serotype. In some embodiments, the ITR and the capsid of the rAAV viral particles are derived from different AAV serotypes. In some embodiments, the recombinant AAV viral particle comprises an AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid. In some embodiments, the AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid comprises a tyrosine mutation or a heparan binding mutation. In some embodiments, the rAAV vector comprises AAV2 ITRs.

[0117] All references cited herein, including patent applications and publications, are incorporated by reference in their entirety. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] FIG. 1 is a schematic diagram of the intronic c.2291+1655 A>G mutation in the CEP290 gene. The A>G mutation occurs at position +5 of the 5' splice site of a cryptic exon located within intron 26. The exon-intron structure of CEP290 exon 26 to exon 27 region is represented by boxes and lines, respectively, together with the splicing pattern for wild-type (solid line) and mutant (dashed line) transcripts. The mutated nucleotide is indicated in bold and underlined, and symbolized by a filled star. The 5' splice site sequences of the cryptic exon are presented along with their splice site strength scores, as calculated by BDGP: Splice Site Prediction by Neural Network (see, e.g., www.fruitfly.org/seq_tools/splice.html and Reese, M.G. et al. (1997) J. Comput. Biol. 4:311-323). Exonic nucleotides are shown in capital letters. Exon and intron sizes are annotated below the figure.

[0119] FIG. 2 is a schematic showing the strategy to delete the intron region flanking the c.2991+1655 A>G mutation of CEP290. An upstream sgRNA directs the first Cas9 cleavage located upstream of the intronic mutation, and a downstream sgRNA directs the second Cas9 cleavage located downstream of the mutation. Note the upstream target locus can be located either upstream of the cryptic exon or within the cryptic exon. The two cleavage ends are directly ligated through the non-homologous end-joining (NHEJ) process, with an intron fragment flanking the c.2991+1655 A>G mutation deleted. Intron 26 is further removed by RNA splicing during mRNA processing.

[0120] FIGS. 3A-3C show the mRNA (FIGS. 3A&3B) and protein (FIG. 3C) expression levels in different cell lines. FIGS. 3A&3B show graphs of basal expression levels of wild- type (FIG. 3A) and mutant (FIG. 3B) mRNAs in wild-type cells (white bars), cells heterozygous for a chromosome bearing the c.2991+1655A>G and c.2991+1666C>G mutations (grey bars), and homozygous c.2991+1655A>G and c.2991+1666C>G cells (mutant cells; black bars), as determined by RT-qPCR. The data are presented as mean + standard deviation of samples from three independent transfections (n=3). Comparisons were performed using one-way ANOVA followed by Tukey's HSD post hoc test. * = p<0.05, ** = p<0.01, *** = p<0.001. FIG. 3C is an immunoblot of lysates prepared from wild-type cells (WT), heterozygous cells (Het), and mutant cells (MT). The membrane was probed for CEP290 (top) and β-Actin as a loading control (bottom). [0121] FIGS. 4A&4B show the efficiency of targeted deletion with paired sgRNAs and SpCas9, as determined by PCR (FIG. 4A) and next-generation sequencing (FIG. 4B). In FIG. 4A, primers outside expected deletion regions were used. The upper bands are PCR products amplified from the Intron 26 of wild-type CEP290, whereas the lower bands are PCR products amplified from CEP290 allele after expected genomic deletions (labeled as "Wt" and "Trunc," respectively). M, 1 kb DNA ladder. FIG. 4B shows percentage of wild- type and truncated of DNA in mutant cells transfected with paired sgRNAs and SpCas9, as determined by next-generation sequencing (NGS).

[0122] FIGS. 5A-5C show rescue of CEP290 expression with paired sgRNAs and SpCas9. FIGS. 5A&5B show expression levels of wild-type (FIG. 5A) and mutant (FIG. 5B) mRNA in wild-type (white bars), heterozygous (grey bars), and mutant (black bars) cells transfected with paired sgRNAs and SpCas9, as measured by RT-qPCR. The data are presented as mean + standard deviation of samples from two independent transfections (n=2). Comparisons were performed using one-way ANOVA followed by Tukey's HSD post hoc test. * = p<0.05, ** = p<0.01. FIG. 5C is an immunoblot of lysates prepared from mutant cells transfected with paired sgRNAs and SpCas9. The membrane was probed for CEP290 (top) and β-Actin as a loading control (bottom).

[0123] FIGS. 6A-6E show a self-limiting CRISPR-SpCas9 system. FIG. 6A is a schematic diagram of the pAAV-SpCas9 vector used in self-limiting CRISPR-SpCas9 system. The recognition sequence for the SpCas9 nuclease (sgRNA target sequence plus the PAM motif) is incorporated into the insertion site 1 (between minCMV promoter and SpCas9) and/or the insertion site 2 (between SpCas9-NLS and SV40 pA). NLS, nuclear localization signal. SV40 pA, Simian virus 40 polyadenylation signal. FIG. 6B is immunoblot of lysates prepared from mutant cells transfected with a first AAV packaging plasmid expressing U1D3 sgRNA pair and a second AAV packaging plasmid expressing SpCas9. The SpCas9 plasmid contains Ul sgRNA recognition sequence (U1T) and/or D3 sgRNA recognition sequence (D3T) in the two insertion sites. The mutant cells transfected with the U1D3 plasmid alone was served as control here. The membrane was probed for SpCas9 (top) and β-Actin as a loading control (bottom). FIG. 6C shows targeted deletion after mutant cells were transfected with U1D3 sgRNA pair and self-limiting SpCas9, as determined by PCR. The upper bands are PCR products amplified from wild-type CEP290 intron 26, whereas the lower bands are PCR products amplified from CEP290 allele after Ul and D3 sgRNAs-guided genomic deletion. M, 1 kb DNA ladder. FIGS. 6D&6E show expression levels of wild-type (FIG. 6D) and mutant (FIG. 6E) mRNA in mutant cells transfected with U1D3 sgRNA pair and self- limiting SpCas9, as measured by RT-qPCR. The data are presented as mean + standard deviation of samples from three independent transfections (n=3). Comparisons were performed using one-way ANOVA followed by Tukey's HSD post hoc test. * = p<0.05, ** = p<0.01, *** = p<0.001 as compared to the cells transfected with the U1D3 sgRNA pair alone.

[0124] FIGS. 7A&7B show deletion of a region in the Intron 25 of Cep290 gene in the mouse retina by a dual AAV system. FIG. 7A is a schematic diagram of the dual AAVs used in subretinal injection. FIG. 7B shows targeted deletion with (1) AAV5-RK-EGFP (control) or AAV5-U11D11 sgRNA pair-RK-EGFP and (2) AAV5-SpCas9, as determined by PCR. The upper bands are PCR products amplified from wild-type mouse Cep290 Intron 25, whereas the lower bands are PCR products amplified from Cep290 allele after Ul 1 and Dl 1 sgRNAs-guided genomic deletion. M, 1 kb DNA ladder.

[0125] FIGS. 8A-8C show targeted deletion with S. aureus Cas9 (SaCas9) and SpCas9, as determined by PCR (FIG. 8A) and by RT-qPCR (FIGS. 8B&8C). Mutant cells were transfected with paired sgRNA pairs together with either SaCas9 or SpCas9. Note that paired sgRNAs and SaCas9 are in one AAV packaging plasmid, whereas paired sgRNAs and SpCas9 are in two separate AAV packaging plasmids. In FIG. 8A, the upper bands are PCR products amplified from the intron 26 of wild-type CEP290, whereas the lower bands are PCR products amplified from CEP290 allele after expected genomic deletions (labeled as "Wt" and "Trunc," respectively). M, 1 kb DNA ladder. FIGS. 8A&8B show expression levels of wild-type (FIG. 8A) and mutant (FIG. 8B) mRNA in mutant cells transfected with paired sgRNAs together with either SaCas9 (white bars) or SpCas9 (grey bars), as measured by RT-qPCR. The data are presented as mean + standard deviation of samples from three independent transfections (n=3). Comparisons were performed using one-way ANOVA followed by Tukey's HSD post hoc test. * = p<0.05, ** = p<0.01, *** = p<0.001. # = p<0.05 as compared to the mutant cells transfected with SaCas9 alone.

DETAILED DESCRIPTION

[0126] The invention provides compositions, methods and viral particles for editing of deep intronic mutations. In some embodiments, the composition for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprises an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats

(CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation. In other embodiments, the composition for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprises nucleic acid encoding an engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) system comprising a) a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation, and b) a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation.

[0127] In some aspects the invention provides compositions, methods and viral particles for treating ocular diseases. As described above, the most frequent genetic cause of LCA is a deep-intronic mutation c.2991+1655A>G in the intron 26 of CEP290 gene, which generates a cryptic splice donor site resulting in the inclusion of an aberrant exon containing a premature stop codon (p.C998X) to CEP290 mRNA (FIG. 1). The inventors have designed a simple and efficient method for treating LCA patients that harbor the intronic c.2991+1655 A>G mutation in the CEP290 gene through a targeted genomic DNA deletion in human cells via a pair of single guide RNAs (sgRNAs) and the Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated protein (Cas) system (FIG. 2). This approach effectively and permanently deletes the intronic c.2991+1655 A>G mutation, preventing the splicing of the cryptic exon inserted into the CEP290 mRNA, and in the meantime leaving the endogenous genetic regulatory elements intact.

I. General Techniques

[0128] The techniques and procedures described or referenced herein are generally well understood and commonly employed using conventional methodology by those skilled in the art, such as, for example, the widely utilized methodologies described in Molecular Cloning: A Laboratory Manual (Sambrook et al., 4 ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 2012); Current Protocols in Molecular Biology (F.M. Ausubel, et al. eds., 2003); the series Methods in Enzymology (Academic Press, Inc.); PCR 2: A Practical Approach (M.J. MacPherson, B.D. Hames and G.R. Taylor eds., 1995); Antibodies, A

Laboratory Manual (Harlow and Lane, eds., 1988); Culture of Animal Cells: A Manual of Basic Technique and Specialized Applications (R.I. Freshney, 6 ^th ed., J. Wiley and Sons, 2010); Oligonucleotide Synthesis (M.J. Gait, ed., 1984); Methods in Molecular Biology, Humana Press; Cell Biology: A Laboratory Notebook (J.E. Cellis, ed., Academic Press, 1998); Introduction to Cell and Tissue Culture (J.P. Mather and P.E. Roberts, Plenum Press, 1998); Cell and Tissue Culture: Laboratory Procedures (A. Doyle, J.B. Griffiths, and D.G. Newell, eds., J. Wiley and Sons, 1993-8); Handbook of Experimental Immunology (D.M. Weir and C.C. Blackwell, eds., 1996); Gene Transfer Vectors for Mammalian Cells (J.M. Miller and M.P. Calos, eds., 1987); PCR: The Polymerase Chain Reaction, (Mullis et al., eds., 1994); Current Protocols in Immunology (J.E. Coligan et al., eds., 1991); Short

Protocols in Molecular Biology (Ausubel et al., eds., J. Wiley and Sons, 2002);

Immunobiology (C.A. Janeway et al., 2004); Antibodies (P. Finch, 1997); Antibodies: A Practical Approach (D. Catty., ed., IRL Press, 1988-1989); Monoclonal Antibodies: A Practical Approach (P. Shepherd and C. Dean, eds., Oxford University Press, 2000); Using Antibodies: A Laboratory Manual (E. Harlow and D. Lane, Cold Spring Harbor Laboratory Press, 1999); The Antibodies (M. Zanetti and J. D. Capra, eds., Harwood Academic

Publishers, 1995); and Cancer: Principles and Practice of Oncology (V.T. DeVita et al., eds., J.B. Lippincott Company, 2011).

II. Definitions

[0129] As used herein, "CRISPR-Cas" refers to a two component ribonucleoprotein complex with guide RNA and a Cas endonuclease. CRISPR refers to the Clustered Regularly Interspaced Short Palindromic Repeats type II system. While CRISPR was discovered as an adaptive defense system that enables bacteria and archaea to detect and silence foreign nucleic acids {e.g., from viruses or plasmids), it has been adapted for use in a variety of cell types to allow for polynucleotide editing in a sequence- specific manner (see, e.g., Jinek, M. et al. (2012) Science 337:816-821 and Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308). In type II systems, guide RNA interacts with Cas and directs the nuclease activity of the Cas enzyme to target DNA sequences identical to the guide RNA guide sequences. Guide RNA base pairs with the opposite strand of the target sequence. Cas nuclease activity then generates a double- stranded break in the target DNA. In some embodiments, the Cas protein is a Cas9 protein.

[0130] As used herein, "CRISPR-Cas single guide RNA" (the terms "single guide RNA" and "sgRNA" may be used interchangeably herein) refers to a single RNA species capable of directing Cas-mediated cleavage of target DNA. In some embodiments, a single guide RNA may contain the sequences necessary for Cas (e.g., Cas9) nuclease activity and a guide sequence identical to a target DNA of interest.

[0131] The terms "chimeric RNA", "chimeric guide RNA", "guide RNA", "single guide RNA" and "synthetic guide RNA" may be used interchangeably herein and refer to the polynucleotide sequence comprising the guide sequence, the tracr sequence and the tracr mate sequence. The term "guide sequence" as used herein refers to the about 20 bp sequence within the guide RNA that specifies the target site and may be used interchangeably with the terms "guide" or "spacer" or "protospacer". The term "tracr mate sequence" may also be used interchangeably with the term "direct repeat(s)."

[0132] As used herein, an "sgRNA guide sequence" may refer to the nucleotide sequence of an sgRNA that binds to the opposite strand of a target DNA sequence and directs Cas (e.g., Cas9) nuclease activity to that locus. In some embodiments, the sgRNA guide sequence is identical to the target sequence. Full identidy is not necessarily required, provided there is sufficient similarity to cause hybridization and promote formation of a CRISPR complex. A guide sequence may comprise any polynucleotide, such as DNA or RNA polynucleotides.

[0133] As used herein, a "Cas" polypeptide is a polypeptide that functions as a nuclease when complexed to a guide RNA, e.g., a sgRNA. In some embodiments, the Cas polypeptide is a Cas9 polypeptide (CRISPR-associated 9, also known as Csnl). When bound to a crRNA:tracrRNA guide or single guide RNA, Cas polypeptides (e.g., Cas9) are able to cleave target DNA at a sequence identical to the sgRNA guide sequence and adjacent to a PAM motif. Unlike other Cas polypeptides, Cas9 polypeptides are characteristic of type II

CRISPR-Cas systems (for a description of Cas proteins of different CRISPR-Cas systems, see Makarova, K.S., et al. (2011) Nat. Rev. Microbiol. 9(6):467-77). As used herein, "Cas" may refer to the ribonucleoprotein complex with an sgRNA or the polypeptide component of the complex, unless specified. [0134] The term "CRISPR RNA (crRNA)" as used herein refers to an RNA comprising the guide sequence used by a CRISPR-Cas system to direct cleavage against a target DNA sequence. The term "trans-activating crRNA (tracrRNA)" as used herein refers to an RNA comprising sequence that forms the structure required for the CRISPR-Cas effector complex that mediates DNA cleavage. In endogenous bacterial and archaeal type II CRISPR-Cas systems, the effector CRISPR-Cas complex includes a Cas protein (e.g., a Cas9 protein) complexed with two polyribonucleotide molecules: a crRNA and a tracrRNA. The crRNA contains an -20 nucleotide guide sequence that mediates target recognition and a sequence that forms a duplex with a tracrRNA. The crRNA: tracrRNA duplex binds the Cas protein and is required for the CRISPR-Cas effector complex function. In some embodiments, the crRNA and tracrRNA functions may be carried out by a single RNA (a single guide RNA or sgRNA) that contains both the sequence that mediates target recognition and the sequence that generates the structure required for the CRISPR-Cas effector complex.

[0135] The term "deep intronic mutation" as used herein refers to a mutation within intronic sequence at a region outside of the wild-type splice acceptor and splice donor sequences. In some cases, a deep intronic mutation may lead to altered splicing of the associated gene, e.g., the inclusion of intronic sequence in the mature mRNA. In non- limiting examples, the deep intronic mutation is greater than about 100 bp downstream (i.e. 3') to an exon, greater than about 100 bp upstream (i.e., 5') to an exon, or greater than about 100 bp downstream of a first exon and greater than about 100 bp upstream of a second exon.

[0136] The term "Leber Congenital Amaurosis (LCA)" as used herein refers to a group of early-onset disorders characterized by vision loss, retinal dysfunction, and nystagmus. A variety of mutations have been implicated in LCA, but LCA is typically inherited as an autosomal recessive disorder. For more description and exemplary LCA disease genes and loci, see, e.g., OMEVI Entry 204000.

[0137] The term "CEP290" as used herein refers to the gene encoding a centrosomal protein involved in ciliogenesis, also known as MKS4, CT87, POC3, rdl6, BBS14, LCA10, JBTS5, NPHP6, SLSN6, and 3HllAg. Mutations in CEP290 have been implicated in LCA. One example of such a mutation is the c.2991+1655A>G mutation that introduces a cryptic splice donor site, resulting in the inclusion of an aberrant exon with a premature stop codon. See, e.g., NCBI Gene ID No. 80184 and UniProt ID No. 015078 for exemplary human gene and protein sequences, respectively. Other examples of CEP290 genes include without limitation mouse CEP290 (e.g., NCBI Gene ID No. 216274), rat CEP290 (e.g., NCBI Gene ID No. 314787), Rhesus monkey CEP290 (e.g., NCBI Gene ID No. 708286), zebrafish CEP290 (e.g., NCBI Gene ID No. 560588), dog CEP290 (e.g., NCBI Gene ID No. 482591), chimpanzee CEP290 (e.g., NCBI Gene ID No. 452113), cat CEP290 (e.g., NCBI Gene ID No. 100113471), chicken CEP290 (e.g., NCBI Gene ID No. 417887), and cow CEP290 (e.g., NCBI Gene ID No. 282707). In some embodiments, a CEP290 gene comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0138] A "vector," as used herein, refers to a recombinant plasmid or virus that comprises a nucleic acid to be delivered into a host cell, either in vitro or in vivo.

[0139] The term "polynucleotide" or "nucleic acid" as used herein refers to a polymeric form of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. Thus, this term includes, but is not limited to, single-, double- or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids, or a polymer comprising purine and pyrimidine bases, or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases. The backbone of the polynucleotide can comprise sugars and phosphate groups (as may typically be found in RNA or DNA), or modified or substituted sugar or phosphate groups. Alternatively, the backbone of the polynucleotide can comprise a polymer of synthetic subunits such as phosphoramidates and thus can be an oligodeoxynucleoside phosphoramidate (P-NH ₂ ) or a mixed phosphoramidate- phosphodiester oligomer. In addition, a double- stranded polynucleotide can be obtained from the single stranded polynucleotide product of chemical synthesis either by synthesizing the complementary strand and annealing the strands under appropriate conditions, or by synthesizing the complementary strand de novo using a DNA polymerase with an appropriate primer.

[0140] The terms "polypeptide" and "protein" are used interchangeably to refer to a polymer of amino acid residues, and are not limited to a minimum length. Such polymers of amino acid residues may contain natural or non-natural amino acid residues, and include, but are not limited to, peptides, oligopeptides, dimers, trimers, and multimers of amino acid residues. Both full-length proteins and fragments thereof are encompassed by the definition. The terms also include post-expression modifications of the polypeptide, for example, glycosylation, sialylation, acetylation, phosphorylation, and the like. Furthermore, for purposes of the present invention, a "polypeptide" refers to a protein which includes modifications, such as deletions, additions, and substitutions (generally conservative in nature), to the native sequence, as long as the protein maintains the desired activity. These modifications may be deliberate, as through site-directed mutagenesis, or may be accidental, such as through mutations of hosts which produce the proteins or errors due to PCR amplification.

[0141] A "recombinant viral vector" refers to a recombinant polynucleotide vector comprising one or more heterologous sequences (i.e. , nucleic acid sequence not of viral origin). In the case of recombinant AAV vectors, the recombinant nucleic acid is flanked by at least one inverted terminal repeat sequence (ITR). In some embodiments, the recombinant nucleic acid is flanked by two ITRs.

[0142] A "recombinant AAV vector (rAAV vector)" refers to a polynucleotide vector comprising one or more heterologous sequences (i.e., nucleic acid sequence not of AAV origin) that are flanked by at least one AAV inverted terminal repeat sequence (ITR). Such rAAV vectors can be replicated and packaged into infectious viral particles when present in a host cell that has been infected with a suitable helper virus (or that is expressing suitable helper functions) and that is expressing AAV rep and cap gene products (i.e. AAV Rep and Cap proteins). When a rAAV vector is incorporated into a larger polynucleotide (e.g. , in a chromosome or in another vector such as a plasmid used for cloning or transfection), then the rAAV vector may be referred to as a "pro-vector" which can be "rescued" by replication and encapsidation in the presence of AAV packaging functions and suitable helper functions. A rAAV vector can be in any of a number of forms, including, but not limited to, plasmids, linear artificial chromosomes, complexed with lipids, encapsulated within liposomes, and encapsidated in a viral particle, e.g., an AAV particle. A rAAV vector can be packaged into an AAV virus capsid to generate a "recombinant adeno-associated viral particle (rAAV particle)".

[0143] An "rAAV virus" or "rAAV viral particle" refers to a viral particle composed of at least one AAV capsid protein and an encapsidated rAAV vector genome.

[0144] A "recombinant adenoviral vector" refers to a polynucleotide vector comprising one or more heterologous sequences (i.e. , nucleic acid sequence not of adenovirus origin) that are flanked by at least one adenovirus inverted terminal repeat sequence (ITR). In some embodiments, the recombinant nucleic acid is flanked by two inverted terminal repeat sequences (ITRs). Such recombinant viral vectors can be replicated and packaged into infectious viral particles when present in a host cell that is expressing essential adenovirus genes deleted from the recombinant viral genome (e.g. , El genes, E2 genes, E4 genes, etc.). When a recombinant viral vector is incorporated into a larger polynucleotide (e.g., in a chromosome or in another vector such as a plasmid used for cloning or transfection), then the recombinant viral vector may be referred to as a "pro-vector" which can be "rescued" by replication and encapsidation in the presence of adenovirus packaging functions. A recombinant viral vector can be in any of a number of forms, including, but not limited to, plasmids, linear artificial chromosomes, complexed with lipids, encapsulated within liposomes, and encapsidated in a viral particle, for example, an adenovirus particle. A recombinant viral vector can be packaged into an adenovirus virus capsid to generate a "recombinant adenoviral particle."

[0145] A "recombinant lentivirus vector" refers to a polynucleotide vector comprising one or more heterologous sequences (i.e. , nucleic acid sequence not of lentivirus origin) that are flanked by at least one lentivirus terminal repeat sequences (LTRs). In some embodiments, the recombinant nucleic acid is flanked by two lentiviral terminal repeat sequences (LTRs). Such recombinant viral vectors can be replicated and packaged into infectious viral particles when present in a host cell that has been infected with a suitable helper functions. A recombinant lentiviral vector can be packaged into a lentivirus capsid to generate a

"recombinant lentiviral particle."

[0146] A "recombinant herpes simplex vector (recombinant HSV vector)" refers to a polynucleotide vector comprising one or more heterologous sequences (i.e. , nucleic acid sequence not of HSV origin) that are flanked by HSV terminal repeat sequences. Such recombinant viral vectors can be replicated and packaged into infectious viral particles when present in a host cell that has been infected with a suitable helper functions. When a recombinant viral vector is incorporated into a larger polynucleotide (e.g., in a chromosome or in another vector such as a plasmid used for cloning or transfection), then the recombinant viral vector may be referred to as a "pro-vector" which can be "rescued" by replication and encapsidation in the presence of HSV packaging functions. A recombinant viral vector can be in any of a number of forms, including, but not limited to, plasmids, linear artificial chromosomes, complexed with lipids, encapsulated within liposomes, and encapsidated in a viral particle, for example, an HSV particle. A recombinant viral vector can be packaged into an HSV capsid to generate a "recombinant herpes simplex viral particle." [0147] "Heterologous" means derived from a genotypically distinct entity from that of the rest of the entity to which it is compared or into which it is introduced or incorporated. For example, a polynucleotide introduced by genetic engineering techniques into a different cell type is a heterologous polynucleotide (and, when expressed, can encode a heterologous polypeptide). Similarly, a cellular sequence (e.g., a gene or portion thereof) that is incorporated into a viral vector is a heterologous nucleotide sequence with respect to the vector.

[0148] The term "transgene" refers to a polynucleotide that is introduced into a cell and is capable of being transcribed into RNA and optionally, translated and/or expressed under appropriate conditions. In aspects, it confers a desired property to a cell into which it was introduced, or otherwise leads to a desired therapeutic or diagnostic outcome. In another aspect, it may be transcribed into a molecule that mediates RNA interference, such as miRNA, siRNA, or shRNA.

[0149] The terms "genome particles (gp)," "genome equivalents," or "genome copies" as used in reference to a viral titer, refer to the number of virions containing the recombinant AAV DNA genome, regardless of infectivity or functionality. The number of genome particles in a particular vector preparation can be measured by procedures such as described in the Examples herein, or for example, in Clark et al. (1999) Hum. Gene Ther., 10: 1031- 1039; Veldwijk et al. (2002) Mol. Ther., 6:272-278.

[0150] The term "vector genome (vg)" as used herein may refer to one or more

polynucleotides comprising a set of the polynucleotide sequences of a vector, e.g., a viral vector. A vector genome may be encapsidated in a viral particle. Depending on the particular viral vector, a vector genome may comprise single-stranded DNA, double-stranded DNA, or single- stranded RNA, or double-stranded RNA. A vector genome may include endogenous sequences associated with a particular viral vector and/or any heterologous sequences inserted into a particular viral vector through recombinant techniques. For example, a recombinant AAV vector genome may include at least one ITR sequence flanking a promoter, a stuffer, a sequence of interest (e.g., an RNAi), and a polyadenylation sequence. A complete vector genome may include a complete set of the polynucleotide sequences of a vector. In some embodiments, the nucleic acid titer of a viral vector may be measured in terms of vg/mL. Methods suitable for measuring this titer are known in the art (e.g., quantitative PCR). [0151] The terms "infection unit (iu)," "infectious particle," or "replication unit," as used in reference to a viral titer, refer to the number of infectious and replication-competent recombinant AAV vector particles as measured by the infectious center assay, also known as replication center assay, as described, for example, in McLaughlin et al. (1988) J. Virol., 62: 1963-1973.

[0152] The term "transducing unit (tu)" as used in reference to a viral titer, refers to the number of infectious recombinant AAV vector particles that result in the production of a functional transgene product as measured in functional assays such as described in Examples herein, or for example, in Xiao et al. (1997) Exp. Neurobiol., 144: 113-124; or in Fisher et al. (1996) J. Virol., 70:520-532 (LFU assay).

[0153] An "inverted terminal repeat" or "ITR" sequence is a term well understood in the art and refers to relatively short sequences found at the termini of viral genomes which are in opposite orientation.

[0154] An "AAV inverted terminal repeat (ITR)" sequence, a term well-understood in the art, is an approximately 145-nucleotide sequence that is present at both termini of the native single-stranded AAV genome. The outermost 125 nucleotides of the ITR can be present in either of two alternative orientations, leading to heterogeneity between different AAV genomes and between the two ends of a single AAV genome. The outermost 125 nucleotides also contains several shorter regions of self-complementarity (designated A, A', B, B', C, C and D regions), allowing intrastrand base-pairing to occur within this portion of the ITR.

[0155] A "terminal resolution sequence" or "trs" is a sequence in the D region of the AAV ITR that is cleaved by AAV rep proteins during viral DNA replication. A mutant terminal resolution sequence is refractory to cleavage by AAV rep proteins.

[0156] A "helper virus" for AAV refers to a virus that allows AAV (which is a defective parvovirus) to be replicated and packaged by a host cell. A number of such helper viruses have been identified, including adenoviruses, herpesviruses and poxviruses such as vaccinia. The adenoviruses encompass a number of different subgroups, although Adenovirus type 5 of subgroup C (Ad5) is most commonly used. Numerous adenoviruses of human, non-human mammalian and avian origin are known and are available from depositories such as the ATCC. Viruses of the herpes family, which are also available from depositories such as ATCC, include, for example, herpes simplex viruses (HSV), Epstein-Barr viruses (EBV), cytomegaloviruses (CMV) and pseudorabies viruses (PRV).

[0157] "Percent (%) sequence identity" with respect to a reference polypeptide or nucleic acid sequence is defined as the percentage of amino acid residues or nucleotides in a candidate sequence that are identical with the amino acid residues or nucleotides in the reference polypeptide or nucleic acid sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid or nucleic acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software programs, for example, those described in Current Protocols in Molecular Biology (Ausubel et ah, eds., 1987), Supp. 30, section 7.7.18, Table 7.7.1, and including BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software. An example of an alignment program is ALIGN Plus (Scientific and Educational Software, Pennsylvania). Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. For purposes herein, the % amino acid sequence identity of a given amino acid sequence A to, with, or against a given amino acid sequence B (which can alternatively be phrased as a given amino acid sequence A that has or comprises a certain % amino acid sequence identity to, with, or against a given amino acid sequence B) is calculated as follows: 100 times the fraction X/Y, where X is the number of amino acid residues scored as identical matches by the sequence alignment program in that program's alignment of A and B, and where Y is the total number of amino acid residues in B. It will be appreciated that where the length of amino acid sequence A is not equal to the length of amino acid sequence B, the % amino acid sequence identity of A to B will not equal the % amino acid sequence identity of B to A. For purposes herein, the % nucleic acid sequence identity of a given nucleic acid sequence C to, with, or against a given nucleic acid sequence D (which can alternatively be phrased as a given nucleic acid sequence C that has or comprises a certain % nucleic acid sequence identity to, with, or against a given nucleic acid sequence D) is calculated as follows: 100 times the fraction W/Z, where W is the number of nucleotides scored as identical matches by the sequence alignment program in that program's alignment of C and D, and where Z is the total number of nucleotides in D. It will be appreciated that where the length of nucleic acid sequence C is not equal to the length of nucleic acid sequence D, the % nucleic acid sequence identity of C to D will not equal the % nucleic acid sequence identity of D to C.

[0158] An "isolated" molecule (e.g. , nucleic acid or protein) or cell means it has been identified and separated and/or recovered from a component of its natural environment.

[0159] An "effective amount" is an amount sufficient to effect beneficial or desired results, including clinical results (e.g. , amelioration of symptoms, achievement of clinical endpoints, and the like). An effective amount can be administered in one or more administrations. In terms of a disease state, an effective amount is an amount sufficient to ameliorate, stabilize, or delay development of a disease.

[0160] An "individual" or "subject" is a mammal. Mammals include, but are not limited to, domesticated animals (e.g., cows, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates such as monkeys), rabbits, and rodents (e.g., mice and rats). In certain embodiments, the individual or subject is a human.

[0161] As used herein, "treatment" is an approach for obtaining beneficial or desired clinical results. For purposes of this invention, beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, diminishment of extent of disease, stabilized (e.g., not worsening) state of disease, preventing spread (e.g., metastasis) of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. "Treatment" can also mean prolonging survival as compared to expected survival if not receiving treatment.

[0162] As used herein, the term "prophylactic treatment" refers to treatment, wherein an individual is known or suspected to have or be at risk for having a disorder but has displayed no symptoms or minimal symptoms of the disorder. An individual undergoing prophylactic treatment may be treated prior to onset of symptoms.

[0163] As used herein, a "therapeutic" agent (e.g., a therapeutic polypeptide, nucleic acid, or transgene) is one that provides a beneficial or desired clinical result, such as the exemplary clinical results described above. As such, a therapeutic agent may be used in a treatment as described above. [0164] The term "central retina" as used herein refers to the outer macula and/or inner macula and/or the fovea. The term "central retina cell types" as used herein refers to cell types of the central retina, such as, for example, RPE and photoreceptor cells.

[0165] The term "macula" refers to a region of the central retina in primates that contains a higher relative concentration of photoreceptor cells, specifically rods and cones, compared to the peripheral retina. The term "outer macula" as used herein may also be referred to as the "peripheral macula". The term "inner macula" as used herein may also be referred to as the "central macula".

[0166] The term "fovea" refers to a small region in the central retina of primates of approximately equal to or less than 0.5 mm in diameter that contains a higher relative concentration of photoreceptor cells, specifically cones, when compared to the peripheral retina and the macula.

[0167] The term "subretinal space" as used herein refers to the location in the retina between the photoreceptor cells and the retinal pigment epithelium cells. The subretinal space may be a potential space, such as prior to any subretinal injection of fluid. The subretinal space may also contain a fluid that is injected into the potential space. In this case, the fluid is "in contact with the subretinal space." Cells that are "in contact with the subretinal space" include the cells that border the subretinal space, such as RPE and photoreceptor cells.

[0168] The term "bleb" as used herein refers to a fluid space within the subretinal space of an eye. A bleb of the invention may be created by a single injection of fluid into a single space, by multiple injections of one or more fluids into the same space, or by multiple injections into multiple spaces, which when repositioned create a total fluid space useful for achieving a therapeutic effect over the desired portion of the subretinal space.

[0169] Reference to "about" a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. For example, description referring to "about X" includes description of "X."

[0170] As used herein, the singular form of the articles "a," "an," and "the" includes plural references unless indicated otherwise. [0171] It is understood that aspects and embodiments of the invention described herein include "comprising," "consisting," and/or "consisting essentially of aspects and embodiments.

III. CRISPR-Cas

[0172] Certain aspects of the present disclosure relate to engineered, non-naturally occurring Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)— CRISPR associated (Cas) (CRISPR-Cas) systems. These systems may be used, inter alia, for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual, e.g., an ocular disease or disorder associated with a deep intronic mutation. In some

embodiments, the CRISPR-Cas systems include a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking the deep intronic mutation; and a nucleotide sequence encoding a Cas protein, wherein the Cas protein cleaves the target DNA molecule at sites flanking the deep intronic mutation thereby excising a portion of the target DNA comprising the deep intronic mutation.

[0173] As described above, the CRISPR-Cas systems were originally discovered as an adaptive defense against foreign nucleic acids in bacteria and archaea. Indeed, CRISPR loci have been identified in more than 40 prokaryotes (see, e.g., Jansen, R. et al. (2002) Mol. Microbiol. 43: 1565-1575 and Mojica, F.J. et al. (2005) J. Mol. Evol. 60: 174-182) including without limitation Aeropyrum, Pyrobaculum, Sulfolobus, Archaeoglobus, Halocarcula, Methanobacteriumn, Methanococcus, Methanosarcina, Methanopyrus, Pyrococcus,

Picrophilus, Thernioplasnia, Corynebacterium, Mycobacterium, Streptomyces, Aquifrx, Porphvromonas, Chlorobium, Thermus, Bacillus, Listeria, Staphylococcus, Clostridium, Thermoanaerobacter, Mycoplasma, Fusobacterium, Azarcus, Chromobacterium, Neisseria, Nitrosomonas, Desulfovibrio, Geobacter, Myrococcus, Campylobacter, Wolinella,

Acinetobacter, Erwinia, Escherichia, Legionella, Methylococcus, Pasteurella,

Photobacterium, Salmonella, Xanthomonas, Yersinia, Treponema, and Thermotoga.

[0174] In bacteria, Cas (e.g., Cas9) proteins bind to two different guide RNAs: a CRISPR RNA (crRNA) and a trans-activating crRNA (tracrRNA). The crRNA and tracrRNA ribonucleotides base pair and form a structure required for the Cas-mediated cleavage of target DNA. However, it has recently been demonstrated that a single guide RNA (sgRNA) may be engineered to form the crRNA:tracrRNA structure and direct Cas-mediated cleavage of target DNA (Jinek, M., et al. (2012) Science 337(6096):816-21). Since the specificity of Cas nuclease activity is determined by the guide RNA, the CRISPR-Cas system has been explored as a tool to direct double-stranded DNA breaks in heterologous cells, enabling customizable genome editing (Mali, P., et al. (2013) Science 339(6121):823-6). Further descriptions of exemplary CRISPR-Cas systems and methods of use related thereto may be found, inter alia, in U.S. Patent No. 8,697,359. In some embodiments, a guide RNA as described herein (e.g., a first or second guide RNA) comprises a single guide RNA (sgRNA) comprising a CRISPR RNA (crRNA) and a trans-activating crRNA (tracrRNA). In some embodiments, a guide RNA as described herein (e.g., a first or second guide RNA) is fused to a trans-activating cr (tracr) sequence. In some embodiments, the trans-activating cr (tracr) sequence comprises the sequence of SEQ ID NO: 25.

[0175] As such, the CRISPR-Cas systems described herein may contrast with a naturally occurring CRISPR-Cas system for many reasons. For example, inter alia, the CRISPR-Cas systems of the present disclosure may include one or more guide RNAs that hybridize to a non-natural sequence (e.g., a eukaryotic intron). Naturally occurring CRISPR-Cas systems recognize sequence that bacteria and archaea are typically exposed to, such as plasmid or phage sequence. Also, many of the CRISPR-Cas systems of the present disclosure include a single guide RNA, whereas naturally occurring CRISPR-Cas systems typically involve separate CRISPR RNAs (crRNAs) and trans-activating crRNAs (tracrRNAs).

[0176] In some embodiments, a CRISPR-Cas system described herein may be self-limiting. For example, as described below, a CRISPR-Cas system may include one or more guide RNAs that hybridize to target sequence(s) within the system itself, e.g., sequence(s) whose cleavage affects the expression level of system components, such as a Cas protein. Without wishing to be bound to theory, it is thought that since the CRISPR-Cas system need not be persistently expressed in a host cell, engineering the system to be "self-limiting" (e.g., characterized by reduced persistence and/or expression) may be advantageous, e.g., for reducing off-target effects, reducing the potential for unwanted immune responses and/or safety problems, and so forth.

[0177] In a self-limiting CRISPR-Cas system, the CRISPR-Cas complex targets one or more sites in the vector used to express one or more components of the complex itself. Thus, upon expression of the guide RNA(s) and the Cas protein, the CRISPR-Cas system targets a locus of interest (e.g. , the site of a mutation as described herein) as well as one or more target(s) in the Cas vector, eventually leading to cleavage of the Cas vector and reduction or elimination of Cas protein expression (after cleavage at the locus of interest). Example 3 infra demonstrates that such a self-limiting CRISPR-Cas system is characterized by decreased Cas persistence time while still allowing for effective cleavage at target sequence(s) of interest (e.g. , excision of a deep intronic mutation).

[0178] Certain aspects of the present disclosure relate to methods for treating a disease or disorder associated with a mutation in a gene of an individual using a self-limiting CRISPR- Cas system. For example, the mutation may be an unwanted sequence (e.g. , a deep intronic mutation) that is excised from the gene of the individual by the CRISPR-Cas system. In other embodiments, the mutation may be a missense, point, or other mutation that is corrected by the CRISPR-Cas system (e.g., homologous DNA repair at the cleaved DNA sequence, particularly if a homology template is included). In some embodiments, the CRISPR-Cas system is in a composition. In some embodiments, the composition is administered to the individual in a therapeutically effective amount.

[0179] In some embodiments, the composition includes a) a nucleic acid encoding a CRISPR-Cas system comprising a first guide RNA and a second guide RNA, wherein the first guide RNA and the second guide RNA hybridize to opposite strands of target DNA sequences flanking a mutation of interest (including but not limited to a deep intronic mutation described herein); and b) a Cas expression cassette. In some embodiments, the Cas expression cassette includes a nucleotide sequence encoding a Cas protein, and a guide RNA target site. The first or second guide RNA hybridizes to the guide RNA target site, thus allowing the CRISPR-Cas system to catalyze cleavage at the guide RNA target site. The guide RNA target site may also include a protospacer adjacent motif (PAM), specific for the Cas protein, adjacent to the sequence that hybridizes to the guide RNA. Upon expression of the Cas protein, the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation. Upon expression of the Cas protein, the Cas protein also cleaves the Cas expression cassette at the guide RNA target site, thereby reducing expression of the Cas protein. As such, Cas expression initially increases following introduction of the Cas expression cassette to the cell, but as Cas protein accumulates in the cell, the Cas protein cleaves the Cas expression cassette. As more of the Cas expression cassette is interrupted by the Cas protein, expression of additional Cas protein is reduced (i.e., the Cas limits expression of its own expression cassette and may be considered a self-limiting Cas expression cassette). In some embodiments, expression of the Cas protein is characterized by an intial increase, followed by a decline in expression following cleavage at the guide RNA target site. As described herein, reducing expression of the Cas protein may refer to reducing the amount and/or persistence of the Cas protein. In some embodiments, expression of the Cas protein may be reduced compared with prior to cleavage of the Cas expression cassette (e.g., compared to initial expression of Cas). In some embodiments, expression of the Cas protein may be reduced compared with the use of a Cas expression cassette lacking the guide RNA target site. In some embodiments, the

composition comprising a self-limiting Cas expression cassette may be used to cleave a target nucleic acid. In some embodiments, the composition may be used to cleave a target nucleic acid in vitro or in vivo. In some embodiments, the composition may be used to cleave a target nucleic acid comprising a mutation (e.g. a deep intronic mutation). For example, the self-limiting Cas expression cassette is used to treat a disease or disorder associated with a mutation in a nucleic acid.

[0180] In some embodiments, the Cas expression cassette further includes a second guide RNA target site, wherein the first guide RNA or the second guide RNA hybridizes to the second guide RNA target site, and wherein the second guide RNA target site is adjacent to a protospacer adjacent motif (PAM) specific for the Cas protein. Upon expression of the Cas protein, the Cas protein cleaves the target DNA sequences flanking the mutation, thereby excising a portion of target DNA comprising the mutation. Further upon expression of the Cas protein, the Cas protein cleaves the Cas expression cassette at both guide RNA target sites, thereby reducing expression of the Cas protein. As exemplified below, one guide RNA may hybridize to two guide RNA target sites; a first guide RNA may hybridize to a first guide RNA target site, and a second guide RNA may hybridize to a second guide RNA target site; or a second guide RNA may hybridize to a first guide RNA target site, and a first guide RNA may hybridize to a second guide RNA site.

[0181] In some embodiments, the Cas expression cassette may include one or more promoters, enhancers, introns, polyadenylation (polyA) sequences, terminators, regulatory elements present in 5' or 3' untranslated regions, and so forth useful for directing/promoting the expression of the Cas protein. In some embodiments, the nucleotide sequence encoding the Cas protein may be operably linked to a promoter. In some embodiments, a guide RNA target site may be between the promoter and the nucleotide sequence encoding the Cas protein, resulting in decreased expression of the Cas protein upon cleavage. In some embodiments, expression of Cas protein is decreased by cleavage of the operable link between the promoter and the nucleotide sequence encoding the Cas protein. In some embodiments, the nucleotide sequence encoding the Cas protein may be operably linked to a polyA sequence. In some embodiments, a guide RNA target site may be between the polyA sequence and the nucleotide sequence encoding the Cas protein, resulting in decreased expression of the Cas protein upon cleavage. In some embodiments, expression of Cas protein is decreased by cleavage of the operable link between the nucleotide sequence encoding the Cas protein and the polyadenylation sequence. In some embodiments, a first guide RNA target site may be between the promoter and the nucleotide sequence encoding the Cas protein, and a second guide RNA target site may be between the polyA sequence and the nucleotide sequence encoding the Cas protein, resulting in decreased expression of the Cas protein upon cleavage. In some embodiments, the Cas protein may be fused in-frame to one or more NLS(s), and a guide RNA target site may be between the sequence encoding the one or more NLS(s) and a polyA sequence (particularly if the NLS(s) are fused to the C- terminus of the Cas protein), resulting in decreased expression of the NLS-fused Cas protein upon cleavage.

[0182] As described herein, a CRISPR-Cas system such as a self-limiting CRISPR-Cas system may be encoded on one or more vectors, such as any of the vectors or viral vectors/particles described herein. In some embodiments, the nucleic acid encoding the first and second guide RNAs may be on the same vector as the Cas expression cassette. In other embodiments, the nucleic acid encoding the first and second guide RNAs may be a different vector than the Cas expression cassette. For example, the first and second guide RNAs may be encoded by a first rAAV vector, and the Cas expression cassette may be encoded by a second rAAV vector. In some embodiments, the target cell may be transfected with both vectors, thus leading to expression of the self-limiting CRISPR-Cas system.

[0183] In some embodiments, the Cas protein cleaves the target DNA molecule at sites flanking a mutation (e.g. , a deep intronic mutation) thereby excising a portion of the target DNA comprising the mutation. For example, a DNA repair process such as non-homologous end joining (NHEJ) may repair the cleaved DNA sequence by joining the cleaved ends, thereby excising the portion of the target DNA comprising the deep intronic mutation. In other examples, homologous DNA repair may repair the cleaved DNA sequence, particularly if a homology template is included. As described and exemplified herein, the use of two guide RNAs that flank a target DNA sequence (e.g., a sequence bearing a deep intronic mutation) allows the excision of a portion of the target DNA sequence, such as the sequence bearing the deep intronic mutation (see also Brandl, C. et al. (2014) FEBS Open Bio. 5:26-35; Zheng, Q. et al. (2014) Biotechniques 57: 115-124 for descriptions of exemplary gene deletion strategies using CRISPR-Cas systems). In some embodiments, the excised portion of the target DNA sequence comprises intronic DNA. In some embodiments, the excised portion of the target DNA sequence consists of only intronic DNA.

[0184] In some embodiments, the first and/or the second guide RNAs hybridize to the opposite strands of the target DNA sequences flanking the mutation (e.g., a deep intronic mutation). Without wishing to be bound to theory, it is thought that the first and/or the second guide RNAs may hybridize to the opposite strands of the target DNA sequences located within the intron at any distance away from the deep intronic mutation. In some embodiments, the first and/or the second guide RNAs hybridize to the opposite strands of the target DNA sequences between 1 base pair and about 10,000 base pairs from the deep intronic mutation. In some embodiments, the first and/or the second guide RNAs hybridize to the opposite strands of the target DNA sequences located less than about any of the following distances from the deep intronic mutation (in nucleotides): 10,000; 9,500; 9,000; 8,500; 8,000; 7,500; 7,000; 6,500; 6,000; 5,500; 5,000; 4,500; 4,000; 3,500; 3,000; 2,500; 2,000; 1,500; 1,000; 950; 900; 850; 800; 750; 700; 650; 600; 550; 500; 450; 400; 350; 300; 250; 200; 150; 100; 95; 90; 85; 80; 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4; 3; 2; or any value therebetween. In some embodiments, the first and/or the second guide RNAs hybridize to the opposite strands of the target DNA sequences located greater than about any of the following distances from the deep intronic mutation (in nucleotides): 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 65; 70; 75; 80; 85; 90; 95; 100; 150; 200; 250; 300; 350; 400; 450; 500; 550; 600; 650; 700; 750; 800; 850; 900; 950; 1,000; 1,500; 2,000; 2,500; 3,000; 3,500; 4,000; 4,500; 5,000; 5,500; 6,000; 6,500; 7,000; 7,500; 8,000; 8,500; 9,000; 9,500; or any value therebetween. That is, the first and/or the second guide RNAs may hybridize to the opposite strands of the target DNA sequences located at a distance from the deep intronic mutation that may be any of a range of distances (in nucleotides) having an upper limit of 10,000; 9,500; 9,000; 8,500; 8,000; 7,500; 7,000; 6,500; 6,000; 5,500; 5,000; 4,500; 4,000; 3,500; 3,000; 2,500; 2,000; 1,500; 1,000; 950; 900; 850; 800; 750; 700; 650; 600; 550; 500; 450; 400; 350; 300; 250; 200; 150; 100; 95; 90; 85; 80; 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4; 3; 2; or any value therebetween and an independently selected lower limit of 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 65; 70; 75; 80; 85; 90; 95; 100; 150; 200; 250; 300; 350; 400; 450; 500; 550; 600; 650; 700; 750; 800; 850; 900; 950; 1,000; 1,500; 2,000; 2,500; 3,000; 3,500; 4,000; 4,500; 5,000; 5,500; 6,000; 6,500; 7,000; 7,500; 8,000; 8,500; 9,000; 9,500; or any value therebetween, wherein the lower limit is less than the upper limit.

[0185] Non-limiting examples of Cas proteins include Casl, CaslB, Cas2, Cas3, Cas4, Cas5, Cas6, Cas7, Cas8, Cas9 (also known as Csnl and Csxl2), CaslO, Csyl, Csy2, Csy3, Csel, Cse2, Cscl, Csc2, Csa5, Csn2, Csm2, Csm3, Csm4, Csm5, Csm6, Cmrl, Cmr3, Cmr4, Cmr5, Cmr6, Csbl, Csb2, Csb3, Csxl7, Csxl4, CsxlO, Csxl6, CsaX, Csx3, Csxl, Csxl5, Csfl, Csf2, Csf3, Csf4, homologs thereof, or modified versions thereof. These enzymes are commonly known in the art.

[0186] In some embodiments the Cas protein (e.g., the CRISPR enzyme) is a Cas9 protein. In some embodiments, the unmodified CRISPR enzyme has DNA cleavage activity, such as Cas9. Exemplary Cas9 proteins include without limitation S. pyogenes Cas9 (see, e.g., SwissProt database Accession No. Q99ZW2), S. aureus Cas9 (see, e.g., GenBank Accession No. CCK74173), S. thermophilus Cas9 (see, e.g., SwissProt database Accession No.

G3ECR1), N. meningitidis Cas9 (see, e.g., UniProt accession number C9X1G5), and T.

denticola Cas9 (see, e.g., GenBank accession number EMB41078). In some embodiments, the Cas9 is from S. pyogenes or S. pneumoniae. In some embodiments, the CRISPR enzyme directs cleavage of one or both strands at the location of a target sequence, such as within the target sequence and/or within the complement of the target sequence. In some embodiments, the CRISPR enzyme directs cleavage of one or both strands within about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 50, 100, 200, 500, or more base pairs from the first or last nucleotide of a target sequence.

[0187] In some embodiments, an enzyme coding sequence encoding a Cas protein of the present disclosure is codon optimized for expression in a particular cell, such as a eukaryotic cell. Eukaryotic cells may be those of or derived from a particular organism, such as a mammal, including but not limited to human, mouse, rat, rabbit, dog, or non-human primate. In general, codon optimization refers to a process of modifying a nucleic acid sequence for enhanced expression in the host cells of interest by replacing at least one codon of the native sequence with codons that are more frequently or most frequently used in the genes of that host cell while maintaining the native amino acid sequence. Various species exhibit particular bias for certain codons of a particular amino acid. Codon usage tables are readily available, for example, at the "Codon Usage Database", and these tables can be adapted in a number of ways (see, e.g., Nakamura, Y. et al. (2000) Nucleic Acids Res. 28:292). Computer algorithms for codon optimizing a particular sequence for expression in a particular host cell are also available, such as Gene Forge (Aptagen; Jacobus, Pa.), are also available.

[0188] In some embodiments, the Cas protein is a fusion protein comprising one or more heterologous protein domains (e.g., about or more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more domains in addition to the CRISPR enzyme). A Cas fusion protein may comprise any additional protein sequence, and optionally a linker sequence between any two domains. Examples of protein domains that may be fused to a Cas protein include, without limitation, epitope tags, reporter gene sequences, and protein domains having one or more of the following activities: methylase activity, demethylase activity, transcription activation activity, transcription repression activity, transcription release factor activity, histone modification activity, RNA cleavage activity and nucleic acid binding activity. Examples of epitope tags include without limitation histidine (His) tags, V5 tags, FLAG tags, influenza hemagglutinin (HA) tags, Myc tags, VSV-G tags, and thioredoxin (Trx) tags. Examples of reporter genes include without limitation glutathione-5-transferase (GST), horseradish peroxidase (HRP), chloramphenicol acetyltransferase (CAT) beta-galactosidase, beta-glucuronidase, luciferase, and fluorescent proteins (e.g., GFP, CFP, YFP, BFP, etc.). A Cas protein may be fused to a gene sequence encoding a protein or a fragment of a protein that bind DNA molecules or bind other cellular molecules, including but not limited to maltose binding protein (MBP), S-tag, Lex A DNA binding domain (DBD) fusions, GAL4A DNA binding domain fusions, and herpes simplex virus (HSV) BP16 protein fusions. In some embodiments, the Cas protein is modified for enhanced function.

[0189] In some embodiments, the Cas protein is a mutant Cas protein. In some

embodiments, the Cas protein (e.g., a Cas9 protien) is a nickase mutant (Ran et al., 2013 Cell 156(6): 1380-9). In some embodiments, a Cas9 nickase mutant is used with pairs of guide RNAs to introduce targeted double-strand breaks with reduced off-target DNA cleavage.

[0190] In some embodiments, the Cas protein is a high-fidelity Cas protein variant harboring amino acid alterations and displaying robust on-target activity but negligible off- target cleavage (Slaymaker, I.M. et al. (2016) Science 351(6268):84-88; Kleinstiver, B.P. et al. (2016) Nature 529:490-495).

[0191] In some embodiments, the CRISPR-Cas system further comprises one or more nuclear localization signal(s) (NLS(s)). For example, the Cas protein {e.g., a Cas9 protein) may comprise one or more NLS(s). Exemplary plasmids including a Cas9 with an NLS may be found in Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308. A variety of NLSs suitable for a range of host cells are known in the art. For example and without limitation, the NLS may be an SV40 NLS {e.g., as described in Mali, P., et al. (2013) Science 339(6121):823-6), an SV40 Large T-antigen monopartite NLS, a nucleoplasmin NLS, and an hnRNP Al NLS. Exemplary NLS sequences that may be used include without limitation PKKKRKV (SEQ ID NO:26) or PKKKRKVEDPKKKRKVD (SEQ ID NO:27) (see, e.g., Jinek, M. et al. (2013) eLife 2:e00471).

[0192] Formation of a CRISPR complex (comprising a guide sequence hybridized to the opposite strand of a target sequence and complexed with one or more Cas proteins) typically results in cleavage of one or both strands in or near (e.g. within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50, or more base pairs from) the target sequence in an endogenous CRISPR system. The tracr sequence, which may comprise all or a portion of a wild-type tracr sequence, is also thought to be able to form part of a CRISPR complex, such as by hybridization along at least a portion of the tracr sequence to all or a portion of a tracr mate sequence, e.g., a tracr mate sequence operably linked to a guide sequence.

[0193] In general, a tracr mate sequence may include any sequence that has sufficient complementarity with a tracr sequence to promote excision of a guide sequence flanked by tracr mate sequences in a cell containing the corresponding tracr sequence; formation of a CRISPR complex comprising the tracr mate sequence hybridized to the tracr sequence at a target sequence; or both. In some embodiments, the tracr sequence has sufficient

complementarity to a tracr mate sequence to hybridize and participate in formation of a CRISPR complex. As described below with respect to target sequences, it is believed that complementarity sufficient at least to be functional is needed {i.e., complete complementarity between the tracr and tracr mate sequences is not required).

[0194] Generally, degree of complementarity refers to the optimal alignment of the tracr mate sequence and tracr sequence, along the length of the shorter of the two sequences. Optimal alignment may be determined by any suitable alignment algorithm (e.g., as described herein), and may further account for secondary structures, such as self-complementarity within either the tracr sequence or tracr mate sequence. In some embodiments, the tracr sequence is about or more than about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, or more nucleotides in length. In some embodiments, the tracr sequence has at least 50%, 60%, 70%, 80%, 90%, 95% or 99% of sequence complementarity along the length of the tracr mate sequence when optimally aligned (e.g., as determined by any of the exemplary alignment methods described herein).

[0195] Without wishing to be bound to theory, it is thought that any desired target DNA sequence of interest may be targeted by an sgRNA guide sequence, and that the only requirement for a target DNA sequence is the presence of a protospacer-adjacent motif (PAM) adjacent to the sgRNA target sequence (Mali, P., et al. (2013) Science

339(6121):823-6). Different Cas complexes are known to have different PAM motifs. For example, Cas9 from Streptococcus pyogenes has a GG dinucleotide PAM motif. For further examples, the PAM motif of S. aureus Cas9 is GRRT in which R is a purine (A or G), the PAM motif of N. meningitidis Cas9 is GATT, the PAM motif of S. thermophilus Cas9 is AGAA, and the PAM motif of T. denticola Cas9 is AAAAC.

[0196] In general, a guide sequence may be any polynucleotide sequence having sufficient similarity with a target polynucleotide sequence to hybridize with the opposite strand of the target sequence and direct sequence-specific binding of a CRISPR complex to the target sequence. In some embodiments, the degree of identity between a guide sequence and its corresponding target sequence is about or more than about 50%, 60%, 75%, 80%, 85%, 90%, 95%, 97.5%, 99%, or more when optimally aligned using a suitable alignment algorithm. Optimal alignment may be determined with the use of any suitable algorithm for aligning sequences; non-limiting examples include the Smith-Waterman algorithm, the Needleman- Wunsch algorithm, algorithms based on the Burrows-Wheeler Transform (e.g. the Burrows Wheeler Aligner), ClustalW, Clustal X, BLAT, Novoalign (Novocraft Technologies, ELAND (Illumina, San Diego, Calif.), SOAP (available at soap.genomics.org.cn), Maq (available at maq.sourceforge.net), and the like.

[0197] In some embodiments, a guide sequence is about or more than about any one of 5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 75, or more nucleotides in length. In some embodiments, a guide sequence is less than about any one of 75, 50, 45, 40, 35, 30, 25, 20, 15, 12, or fewer nucleotides in length. Assays for determining the ability of a guide sequence to direct sequence- specific binding of a CRISPR complex to a target sequence are known in the art. For example, the components of a

CRISPR system sufficient to form a CRISPR complex, including the guide sequence to be tested, may be provided to a host cell having the corresponding target sequence, such as by transfection with vectors encoding the components of the CRISPR sequence, followed by an assessment of preferential cleavage within the target sequence, e.g., as described in U.S. Patent No. 8,697,359.

[0198] In some embodiments, a guide RNA of the present disclosure (e.g., a first guide RNA) comprises the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for

SaCas9), SEQ ID NO:46 (for SaCas9), or SEQ ID NO:47(for SaCas9). In some

embodiments, a guide RNA of the present disclosure (e.g., a first guide RNA) comprises the sequence of SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9). In some embodiments, the guide RNA comprises 1, 2, 3, 4, or 5 substitutions, deletions or insertions of the sequences of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), SEQ ID NO:47(for SaCas9), SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9) while maintaining its function as a guide RNA for Cas cleavage of the CEP290 gene. In some embodiments, the guide RNA is a variant of the guide RNA of SEQ ID NO:41 (for SpCas9), SEQ ID NO:45 (for SaCas9), SEQ ID NO:46 (for SaCas9), SEQ ID NO:47(for SaCas9), SEQ ID NO: 19 (for SpCas9), SEQ ID NO:50 (for SaCas9), SEQ ID NO:51 (for SaCas9), or SEQ ID NO:52 (for SaCas9) with enhanced function as a guide RNA for Cas cleavage of the CEP290 gene.

[0199] In some embodiments, a guide RNA of the present disclosure (e.g., a second guide RNA) comprises the sequences of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for

SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), or SEQ ID NO:49 (for SaCas9). In some embodiments, a guide RNA of the present disclosure (e.g., a second guide RNA) comprises the sequences of SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for

SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9). In some embodiments, the guide RNA comprises 1, 2, 3, 4, or 5 substitutions, deletions or insertions of the sequences of SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17 or SEQ ID NO: 18 while maintaining its function as a guide RNA for Cas cleavage of the CEP290 gene. In some embodiments, the guide RNA is a variant of the guide RNA of SEQ ID NO:42 (for SpCas9), SEQ ID NO:43 (for SpCas9), SEQ ID NO:44 (for SpCas9), SEQ ID NO:48 (for SaCas9), SEQ ID NO:49 (for SaCas9), SEQ ID NO:20 (for SpCas9), SEQ ID NO:21 (for SpCas9), SEQ ID NO:22 (for SpCas9), SEQ ID NO:53 (for SaCas9), or SEQ ID NO:54 (for SaCas9) with enhanced function as a guide RNA for Cas cleavage of the CEP290 gene.

[0200] In some embodiments, the tracr sequence and tracr mate sequence are contained within a single transcript, such that hybridization between the two produces a transcript having a secondary structure (e.g., a hairpin). In some embodiments, loop forming sequences for use in hairpin structures are four nucleotides in length. In some embodiments, the loop forming sequences have the sequence GAAA. However, longer or shorter loop sequences may be used, as may alternative sequences. Examples of other loop forming sequences include without limitation CAAA and AAAG. In some embodiments, the transcript or transcribed polynucleotide sequence has at least two or more hairpins, e.g, two, three, four or five hairpins. In some embodiments, the single transcript further includes a transcription termination sequence, e.g., a polyT sequence such as six T nucleotides.

IV. Deep Intronic Mutations

[0201] Certain aspects of the present disclosure relate to deep intronic mutations. As described above, a deep intronic mutation may lead to the aberrant inclusion of intronic sequence in a mature (e.g., spliced) mRNA. For example, a deep intronic mutation may introduce a splice donor site, splice acceptor site, or a splicing enhancer site in a gene. As a result, intronic sequence may be included as a cryptic exon. This typically results in a mutated polypeptide, particularly if the cryptic exon includes a frameshift mutation or premature stop codon.

[0202] As described above, a deep intronic mutation refers to a mutation outside of the wild-type splice acceptor and splice donor sequences, i.e., as opposed to a mutation at an endogenous splice acceptor or splice donor. Typically, a deep intronic mutation occurs at some distance from the endogenous splice acceptor/splice donor sites.

[0203] In some embodiments, a deep intronic mutation is located at least about 100 nucleotides from a 5' splice donor site of the gene. In some embodiments, a deep intronic mutation is located at least about 100 nucleotides from a 3' splice acceptor site of the gene. In some embodiments, a deep intronic mutation is located at least about 100 nucleotides from a 5' splice donor and at least about 100 nucleotides from a 3' splice acceptor site of the gene. In some embodiments, a deep intronic mutation occurs at more than about 100 nucleotides, more than about 150 nucleotides, more than about 200 nucleotides, more than about 250 nucleotides, more than about 300 nucleotides, more than about 350 nucleotides, more than about 400 nucleotides, more than about 450 nucleotides, more than about 500 nucleotides, more than about 550 nucleotides, more than about 600 nucleotides, more than about 650 nucleotides, more than about 700 nucleotides, more than about 750 nucleotides, more than about 800 nucleotides, more than about 850 nucleotides, more than about 900 nucleotides, more than about 950 nucleotides, more than about 1,000 nucleotides, more than about 1,500 nucleotides, more than about 2,000 nucleotides, more than about 2,500 nucleotides, more than about 3,000 nucleotides, more than about 3,500 nucleotides, more than about 4,000 nucleotides, more than about 4,500 nucleotides, more than about 5,000 nucleotides, more than about 5,500 nucleotides, more than about 6,000 nucleotides, more than about 6,500 nucleotides, more than about 7,000 nucleotides, more than about 7,500 nucleotides, more than about 8,000 nucleotides, more than about 8,500 nucleotides, more than about 9,000 nucleotides, more than about 9,500 nucleotides, more than about 10,000 nucleotides, more than about 15,000 nucleotides, more than about 20,000 nucleotides, more than about 25,000 nucleotides, more than about 30,000 nucleotides, more than about 35,000 nucleotides, more than about 40,000 nucleotides, more than about 45,000 nucleotides, more than about 50,000 nucleotides, more than about 55,000 nucleotides, more than about 60,000 nucleotides, more than about 65,000 nucleotides, more than about 70,000 nucleotides, more than about 75,000 nucleotides, more than about 80,000 nucleotides, or more than about 85,000 nucleotides from an endogenous splice acceptor and/or splice donor site (e.g., a 5' splice donor and/or 3' splice acceptor site).

[0204] In some embodiments, a deep intronic mutation occurs at a distance from an endogenous splice acceptor and/or splice donor site (e.g., a 5' splice donor site or 3' splice acceptor) that is less than about any of the following distances (in nucleotides): 85,000; 80,000; 75,000; 70,000; 65,000; 60,000; 55,000; 50,000; 45,000; 40,000; 35,000; 30,000; 25,000; 20,000; 15,000; 10,000; 9,500; 9,000; 8,500; 8,000; 7,500; 7,000; 6,500; 6,000; 5,500; 5,000; 4,500; 4,000; 3,500; 3,000; 2,500; 2,000; 1,500; 1,000; 950; 900; 850; 800; 750; 700; 650; 600; 550; 500; 450; 400; 350; 300; 250; 200; or 150. In some embodiments, a deep intronic mutation occurs at a distance from an endogenous splice acceptor and/or splice donor site that is greater than about any of the following distances (in nucleotides): 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900; 950; 1,000; 1,500; 2,000; 2,500; 3,000; 3,500; 4,000; 4,500; 5,000; 5,500; 6,000; 6,500; 7,000; 7,500; 8,000; 8,500; 9,000; 9,500; 10,000; 15,000; 20,000; 25,000; 30,000; 35,000; 40,000; 45,000; 50,000; 55,000; 60,000; 65,000; 70,000; 75,000; or 80,000. That is, distance from the deep intronic mutation to the endogenous splice acceptor and/or splice donor site (e.g., a 5' splice donor site) may be any of a range of distances (in nucleotides) having an upper limit of 85,000; 80,000; 75,000; 70,000; 65,000; 60,000; 55,000; 50,000; 45,000; 40,000; 35,000; 30,000; 25,000; 20,000; 15,000; 10,000; 9,500; 9,000; 8,500; 8,000; 7,500; 7,000; 6,500; 6,000;

5,500; 5,000; 4,500; 4,000; 3,500; 3,000; 2,500; 2,000; 1,500; 1,000; 950; 900; 850; 800; 750; 700; 650; 600; 550; 500; 450; 400; 350; 300; 250; 200; or 150 and an independently selected lower limit of 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900; 950; 1,000; 1,500; 2,000; 2,500; 3,000; 3,500; 4,000; 4,500; 5,000; 5,500; 6,000; 6,500; 7,000; 7,500; 8,000; 8,500; 9,000; 9,500; 10,000; 15,000; 20,000; 25,000;

30,000; 35,000; 40,000; 45,000; 50,000; 55,000; 60,000; 65,000; 70,000; 75,000; or 80,000; wherein the lower limit is less than the upper limit.

[0205] Certain aspects of the present disclosure relate to methods, kits, compositions, and viral particles that may be used, inter alia, for treating a disease or disorder associated with a deep intronic mutation, e.g., in a gene of an individual. A variety of deep intronic mutations are known in the art. Exemplary deep intronic mutations associated with disease are provided in Table 1 below (note that the specific mutations, genes, and intron sizes provided in Table 1 refer to human DNA sequence as the reference).

Table 1. Exemplary diseases associated with deep intronic mutations.

Phenotype Gene Mutation Intron Pub Med size Article #

Autosomal recessive PKHD1 IVS46+653A>G 12453 19021639 polycystic kidney disease

Barth syndrome TAZ IVS3+110G>A 229 11735032

Beta-thalassemia HBB IVS2+645C>T 850 6585831

Beta-thalassemia HBB IVS2+705T>G 850 6298782

Beta-thalassemia HBB IVS2+745C>G 850 6188062

Congenital FGG IVS6+660A>T 979 17854317 afibrinogenemia

Congenital cataracts facial CTDP1 IVS6+389C>T 2505 14517542 dysmorphism neuropathy

syndrome

Congenital disorder of PMM2 IVS7+19139C>T 34617 17307006 glycosylation, type la

Congenital disorder of SLC35A1 IVS6+286insCACT 444 15576474 glycosylation, type II

Cystic fibrosis CFTR IVS 12+1634A>G 2519 7534040

Cystic fibrosis CFTR IVS 19+11505C>G 12808 11134243

Cystic fibrosis CFTR IVS22+12191C>T 14967 1384328

Dihydropteridine reductase QDPR IVS3+2552A>G 9078 9341885 deficiency

Fabry disease GLA IVS4+919G>A 1719 11828341

Familial melanoma CDKN2A IVS2-105A>G 2659 11726555

Familial platelet disorder CYBB IVS5+979G>T 2140 11566256 with predisposition to acute

myelogenous leukemia

Familial platelet disorder CYBB IVS6+1657A>G 2803 16516412 with predisposition to acute

myelogenous leukemia

Fanconi anemia BRIP1 IVS 11+2767A>T 3264 16116423

Gitelman syndrome SLC12A3 IVS 13+1361C>T 1551 19668106

Growth hormone GHR IVS6+792A>G 11204 11468686 insensitivity

Friedrich's ataxia FXN GAA triplet repeat 10437 9259271

Hearing Loss MY06 IVS23+2321T>G 4185 18212818

Hemophilia A F8 IVS 1+1567A>G 22809 18160816

Hemophilia A F8 IVS 10+325 A>G 3903 15284851

Hemophilia A F8 IVS 18+530C>T 1738 23809411 Phenotype Gene Mutation Intron Pub Med size Article #

Hemophilia A F8 IVS 18+941C>T 1738 23809411

Hereditary megaloblastic CUBN IVS23+881C>G 1320 10080186 anaemia 1

Hermansky-Pudlak HPS3 IVS 16+2499G>A 4111 7901342 syndrome

Homocystinuria MTRR IVS6+469T>C 2420 20120036

Maple syrup urine disease DBT IVS8-550A>G 4057 9621512

Marfan syndrome FBN1 IVS63+375G>T 2793 18795226

Methionine synthase MTR IVS3+2305A>G 2470 9683607 deficiency

Methionine synthase MTR IVS6+1088G>A 2759 9683607 deficiency

Methylmalonic acidemia MUT IVS 11+3691C>A 7582 17966092

Mitochondrial trifunctional HADHB IVS7+615A>G 1453 18693053 protein deficiency

Mucopolysaccharidosis, IDS IVS7+3083A>G 3215 8940265 type II

Multi-minicore disease RYR1 IVS 100+2990A>G 4438 12719381

Muscular dystrophy DMD IVS 1+36846G>A 191081 14659407

Muscular dystrophy DMD IVS 1+36947G>A 191081 17041906

Muscular dystrophy DMD IVS2+5591T>A 170318 12522557

Muscular dystrophy DMD IVS9+46806C>T 52717 14659407

Muscular dystrophy DMD IVS25+2036A>G 8606 12754707

Muscular dystrophy DMD IVS25+2240A>G 8606 10094556

Muscular dystrophy DMD IVS27+6298C>A 7141 20485447

Muscular dystrophy DMD IVS60+80228G>T 95846 14659407

Muscular dystrophy DMD IVS62+62296A>G 62581 12754707

Muscular dystrophy DMD IVS65+1215A>G 2830 17041906

Muscular dystrophy DMD IVS67+2714C>T 21056 20485447

Neurofibromatosis, type I NF1 IVS3+2025T>G 4092 19241459

Neurofibromatosis, type I NF1 IVS39+332A>G 4339 8829638

Neurofibromatosis, type I NF1 IVS39+4060A>G 4339 16470740

Neurofibromatosis, type I NF1 IVS54+790C>G 1110 19241459

Niemann-Pick disease, type NPC1 IVS9+2021G>A 3030 19718781 C

Ocular albinism, type I GPR143 IVS7+748G>A 1618 16550551 Phenotype Gene Mutation Intron Pub Med size Article #

Ornithine delta- OAT rVS3+303C>G 3007 1992472 aminotransferase

deficiency

Predisposition to systemic IRF5 rVS l+198G>T 4021 16642019 lupus erythematosus

Propionic acidemia PCCA IVS 14+2778A>G 4193 17966092

Propionic acidemia PCCB IVS6+462A>G 9808 17966092

Rhabdoid tumors SNF5/INI1 IVS 1+559A>G 4493 10556283

Schwartz-Jampel syndrome HSPG2 rVS6+481C>T 1914 16927315

Stickler syndrome COL2A1 IVS23+135G>A 371 16752401

Systemic lupus MFGE8 IVS6+936A>G 1739 20213738 erythematosus

Tuberous sclerosis TSC2 rVS8+281C>T 1568 11068191

Werner syndrome WRN rVS 18+7636A>G 10659 17478382

X-linked CD40L rVS3+1011A>T 1925 15358621 hyperimmunoglobulinemia

M

X-linked PHEX rVS7+1268G>T 2855 11502821 hypopho sphatemia

[0206] In some embodiments, the disease or disorder associated with a deep intronic mutation is afibrinogenemia, Alport syndrome, Amyotrophic lateral sclerosis, ataxia telangiectasia, autosomal recessive polycystic kidney disease, Barth syndrome, beta- thalassemia, congenital afibrinogenemia, congenital cataracts facial dysmorphism neuropathy syndrome, congenital disorder of glycosylation type la, congenital disorder of glycosylation type II, cystic fibrosis, dihydropteridine reductase deficiency, Fabry disease, familial platelet disorder with predisposition to acute myelogenous leukemia, Fanconi anemia, Gitelman syndrome, growth hormone insensitivity, Friedrich's ataxia, hemophilia A, hereditary megaloblastic anaemia 1, Hermansky-Pudlak syndrome, homocytinuria, maple syrup urine disease, Marfan syndrome, methionine synthase deficiency, methylmalonic academia, mitochondrial trifunctional protein deficiency, mucupolysaccaridosis type II, multi-minicore disease, muscular dystrophy, neurofibromatosis type I, Niemann-Pick disease type C, ocular albinism type I, ornithine delta-aminotransferaase deficiency, predisposition to systemic lupus erythematosus, propionic academia, rhabdoid tumors, Schwartz-Jampel syndrome, Stickler syndrome, systemic lupus erythematosus, tuberous sclerosis, Werner syndrome, X- linked hyperimmunoglobulinemia M, or X-linked hypophosphatemia. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 1.

[0207] In some embodiments, the disease or disorder associated with a deep intronic mutation is an ocular disease. As used herein, the term "ocular disease" is used in the broadest sense and may refer to a disease originating in, or resulting in a pathological condition of, any structure of the eye, including without limitation the cornea, iris, lens, retina, optic nerve, aqueous humor, conjunctiva, one or more ocular muscles, sclera, vitreous body, macula, fovea, ciliary body, one or more ligaments or suspensory ligament zonules, pupil, anterior chamber, and/or posterior chamber. Exemplary deep intronic mutations associated with ocular disease are provided in Table 2 below (note that the specific mutations, genes, and intron sizes provided in Table 2 refer to human DNA sequence as the reference).

Table 2. Ocular diseases associated with deep intronic mutations.

[0208] In some embodiments, the ocular disease is Leber congenital amaurosis, optic atrophy, retinitis pigmentosa, retinoblastoma, Stargardt disease, Usher syndrome, or X-linked retinitis pigmentosa. In some embodiments, the deep intronic mutation is a deep intronic mutation presented in Table 2. [0209] In some embodiments, the ocular disease is Leber congenital amaurosis. Leber Congenital Amaurosis (LCA) refers to a group of ocular disorders characterized by symptoms such as severe vision loss, nystagmus, retinal dysfunction, photophobia, oculodigital sign (e.g., rubbing, poking, and pressing of the eye), and keratoconus. LCA typically presents at birth with profound vision loss and nystagmus. While instances of LCA are typically inherited as an autosomal recessive disorder, mutations in a variety of genetic loci have been implicated. For example, Table 3 lists some of the loci implicated in forms of LCA.

Table 3. LCA disease loci.

[0210] The most frequent type of LCA is caused by a mutation in CEP290, which encodes a centrosomal protein that plays an important role in centrosome and cilia development (see, e.g., NCBI Gene ID No. 80184 and UniProt ID No. 015078 for exemplary human gene and protein sequences, respectively). CEP290 is essential in the formation of the primary cilium on the cell membrane that plays an important role in the photoreceptors at the back of the retina and in the kidney, brain, and many other organs of the body. CEP290 is also known as MKS4, CT87, POC3, rdl6, BBS14, LCA10, JBTS5, NPHP6, SLSN6, and 3HllAg. In some embodiments, the causative mutation is a c.2991+1655A>G mutation that introduces a cryptic splice donor site, resulting in the inclusion of an aberrant exon with a premature stop codon. In some embodiments, the first guide RNA and second guide RNA guide sequences hybridize to the opposite strands of the target DNA sequences flanking a deep intronic mutation of the centrosomal protein 290 kDa (CEP290) gene. In certain embodiments, the deep intronic mutation is a c.2991+1655A>G mutation. In some embodiments, the CEP290 is a human CEP290 (see, e.g., the human CEP290 sequence according to NCBI Reference Sequence NG_008417). In some embodiments, the CEP290 comprises a deep intronic mutation of the sequence set forth in SEQ ID NO:23.

[0211] Certain aspects of the present disclosure further relate to methods for generating an in vitro model of an ocular disease associated with deep intronic mutation in a gene. In some embodiments, the methods include introducing to eukaryotic cells nucleic acid encoding a CRISPR-Cas system, wherein the CRISPR-Cas system comprises i) a single guide RNA to target DNA sequences of an intron in the gene, ii) a nucleotide sequence encoding a Cas protein, iii) a single- stranded oligonucleotide comprising a homology directed repair (HDR) template comprising homology arms flanking a desired intronic mutation and a protospacer adjacent motif (PAM); and isolating cells that comprise the mutation incorporated into gene. Exemplary methods related to this approach are illustrated in the Examples below. As described above, CRISPR-Cas-mediated DNA cleavage may be repaired by NHEJ, resulting in, e.g., excision of a target DNA sequence. However, CRISPR-Cas-mediated DNA cleavage may also be repaired by homology directed repair (HDR), resulting in, e.g., introduction of a sequence present in the HDR template {e.g., an introduced deep intronic mutation). See, e.g., Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308. These methods may include any features, aspects, or elements described herein with respect to methods of treatment, viral particles, compositions, and kits.

[0212] A homology directed repair (HDR) template may take a variety of forms, such as a double-stranded DNA polynucleotide or a single-stranded DNA oligonucleotide (ssODN). The HDR template may include one or more homology arms flanking a desired intronic mutation. These homology arms may be in the sense or antisense direction, relative to the target locus. In some embodiments, the one or more homology arms may be at least about 40 base pairs, at least about 50 base pairs, at least about 60 base pairs, at least about 70 base pairs, at least about 80 base pairs, at least about 90 base pairs, or at least about 100 base pairs away from the target locus. [0213] The HDR template may also include a protospacer adjacent motif (PAM). In some embodiments, the PAM comprises a mutation to avoid cleavage of the single- stranded oligonucleotide by an expressed Cas protein in the cells. For example, the PAM may be mutated such that the particular expressed Cas protein does not cleave the HDR template, or mutated such that an identifying sequence (e.g., a unique restriction site, as illustrated in the Examples below) is introduced upon CRISPR-Cas-mediated editing of a genomic locus.

[0214] Any suitable eukaryotic cell may be used for the in vitro model. In some

embodiments, the eukaryotic cell is a mammalian or human cell. In some embodiments, the eukaryotic cell is a cell line, such as a human cell line (e.g., HeLa, A549, 293, and so forth), a mammalian cell line, a vertebrate cell line, or an insect cell line (e.g., Sf9 or S2). In some embodiments, the eukaryotic cell is a retinal cell (e.g., a WERI cell), such as a photoreceptor cell.

V. Methods of Delivery

[0215] Certain aspects of the present disclosure relate to treating a disease or disorder associated with a deep intronic mutation in a gene of an individual. In some aspects, the invention provides methods for treating a disease or disorder associated with a deep intronic mutation in a gene of an individual comprising administering to the individual a

therapeutically effective amount of a composition of the present disclosure, e.g., a

composition comprising nucleic acid encoding an engineered, non-naturally occurring CRISPR-Cas system of the present disclosure. In some embodiments, the nucleic acid encoding the engineered, non-naturally occurring CRISPR-Cas system may be DNA or RNA. In some embodiments, the Cas protein is delivered as a protein.

Vectors

[0216] In some embodiments, the nucleic acid encoding one or more of the first guide RNA, the second guide RNA or the Cas protein are located on the same or different vectors of the system. In some embodiments, one or more vectors driving expression of one or more elements of a CRISPR system are introduced into a cell such that expression of the elements of the CRISPR system direct formation of a CRISPR complex at one or more target sites. For example, a Cas enzyme, a guide sequence linked to a tracr-mate sequence, and a tracr sequence may each be operably linked to separate regulatory elements on separate vectors. Alternatively, two or more of the elements described above may be expressed from the same or different regulatory elements, and/or may be combined in a single vector, optionally with one or more additional vectors providing any components of the CRISPR system not included in the first vector. CRISPR system elements that are combined in a vector may be arranged in any suitable orientation. For example, the coding sequence of one element may be located on the same or opposite strand of the coding sequence of a second element, and/or oriented in the same or opposite direction.

[0217] In some embodiments, a single promoter drives expression of a transcript encoding a Cas protein and one or more of the guide sequence, tracr mate sequence (optionally operably linked to the guide sequence), and a tracr sequence embedded within one or more intron sequences (e.g. each in a different intron, two or more in at least one intron, or all in a single intron). In some embodiments, the Cas protein, guide sequence, tracr mate sequence, and tracr sequence are operably linked to and expressed from the same promoter. In some embodiments, the first guide RNA, the second guide RNA and/or the nucleic acid encoding the Cas protein are operably linked to one or more regulatory control elements and/or promoters.

[0218] In some embodiments, the vector is a plasmid.

[0219] In some embodiments, the first guide RNA, the second guide RNA and the Cas protein are expressed in eukaryotic cells. In some embodiments, the first guide RNA, the second guide RNA and the Cas protein are operably linked to one or more promoters that allow for expression in a eukaryotic cell. A variety of promoters that are expressed in eukaryotic cells are known in the art. Exemplary promoters are provided without limitation below.

[0220] In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III promoter. RNA polymerase III promoters may include a full-length promoter or a fragment thereof sufficient to drive transcription by RNA polymerase III. For a more detailed description of RNA polymerase III promoter types, structural features, and interactions with RNA polymerase III, as well as suitable RNA polymerase III promoters, see Schramm, L. and Hernandez, N. (2002) Genes Dev. 16:2593- 620. Any suitable RNA polymerase III promoter known in the art may be used, including without limitation promoters for a tRNA, 5S RNA, U6 snRNA, HI, 7SK, RNase P, the RNA component of the Signal Recognition Particle, and snoRNAs (see, e.g., Ma, H. et al. (2014) Mol. Ther. Nucleic Acids 3:el61). In some embodiments, the RNA polymerase III promoter is a U6, HI, or 7SK promoter. In some embodiments, the first guide RNA and/or the second guide RNA is operably linked to a RNA polymerase III terminator. Examples of RNA polymerase III terminators may include, without limitation, a string of uridine nucleotides of at least 5-6 bases in length (for more information on RNA polymerase III terminators, see Marck, C, et al. (2006) Nucleic Acids Res 34(6): 1816-35).

[0221] In some embodiments, the nucleic acid encoding the Cas protein is operably linked to a RNA polymerase II promoter. RNA polymerase II promoters may include a full-length promoter or a fragment thereof sufficient to drive transcription by RNA polymerase II. Any suitable RNA polymerase II promoter known in the art may be used, including without limitation the cytomegalovirus (CMV) immediate early promoter, the minimal promoter fragment derived from the CMV promoter (minCMV promoter), the RSV LTR, the MoMLV LTR, the phosphoglycerate kinase- 1 (PGK) promoter, a simian virus 40 (SV40) promoter and a CK6 promoter, a transthyretin promoter (TTR), a TK promoter, a tetracycline responsive promoter (TRE), an HBV promoter, an hAAT promoter, a LSP promoter, chimeric liver- specific promoters (LSPs), the E2F promoter, the telomerase (hTERT) promoter; the cytomegalovirus enhancer/chicken beta-actin/Rabbit β-globin promoter (CAG promoter; Niwa et al., Gene, 1991, 108(2): 193-9) and the elongation factor 1-alpha promoter (EFl-alpha) promoter (Kim et al., Gene, 1990, 91(2):217-23 and Guo et al., Gene Ther., 1996, 3(9):802-10). In some embodiments, the promoter comprises a human β-glucuronidase promoter or a cytomegalovirus enhancer linked to a chicken β-actin (CBA) promoter. The promoter can be a constitutive, inducible or repressible promoter. In some embodiments, the promoter is capable of expressing the heterologous nucleic acid in a cell of the eye. In some embodiments, the promoter is capable of expressing the heterologous nucleic acid in photoreceptor cells or RPE. In embodiments, the promoter is a rhodopsin kinase (RK) promoter; e.g., a human RK promoter. In some embodiments, the promoter is an opsin promoter; e.g., a human opsin promoter or a mouse opsin promoter. In some embodiments, the promoter is a rod opsin promoter, a cone opsin promoter, a beta phosphodiesterase (PDE) promoter, a retinitis pigmentosa (RP1) promoter, or an interphotoreceptor retinoid-binding protein gene (IRBP) promoter.

[0222] Inducible promoters allow regulation of gene expression and can be regulated by exogenously supplied compounds, environmental factors such as temperature, or the presence of a specific physiological state, e.g., acute phase, a particular differentiation state of the cell, or in replicating cells only. Inducible promoters and inducible systems are available from a variety of commercial sources, including, without limitation, Invitrogen, Clontech and Ariad. Many other systems have been described and can be readily selected by one of skill in the art. Examples of inducible promoters regulated by exogenously supplied promoters include the zinc-inducible sheep metallothionine (MT) promoter, the dexamethasone (Dex) -inducible mouse mammary tumor virus (MMTV) promoter, the T7 polymerase promoter system (WO 98/10088); the ecdysone insect promoter (No et al, Proc. Natl. Acad. Sci. USA, 93:3346- 3351 (1996)), the tetracycline-repressible system (Gossen et al., Proc. Natl. Acad. Sci. USA, 89:5547-5551 (1992)), the tetracycline-inducible system (Gossen et al., Science, 268: 1766- 1769 (1995), see also Harvey et al, Curr. Opin. Chem. Biol, 2:512-518 (1998)), the RU486- inducible system (Wang et al, Nat. Biotech., 15:239-243 (1997) and Wang et al, Gene Ther., 4:432-441 (1997)) and the rapamycin-inducible system (Magari et al, J. Clin. Invest., 100:2865-2872 (1997)). Still other types of inducible promoters which may be useful in this context are those which are regulated by a specific physiological state, e.g., temperature, acute phase, a particular differentiation state of the cell, or in replicating cells only.

[0223] In another embodiment, the native promoter, or fragment thereof, for the transgene will be used. The native promoter can be used when it is desired that expression of the transgene should mimic the native expression. The native promoter may be used when expression of the transgene must be regulated temporally or developmentally, or in a tissue- specific manner, or in response to specific transcriptional stimuli. In a further embodiment, other native expression control elements, such as enhancer elements, polyadenylation sites or Kozak consensus sequences may also be used to mimic the native expression.

[0224] In some embodiments, the regulatory sequences impart tissue-specific gene expression capabilities. In some cases, the tissue- specific regulatory sequences bind tissue- specific transcription factors that induce transcription in a tissue specific manner. Such tissue- specific regulatory sequences (e.g., promoters, enhancers, etc.) are well known in the art. Exemplary tissue- specific regulatory sequences include, but are not limited to the following tissue specific promoters: neuronal such as neuron-specific enolase (NSE) promoter

(Andersen et al, Cell. Mol. Neurobiol, 13:503-15 (1993)), neurofilament light-chain gene promoter (Piccioli et al, Proc. Natl. Acad. Sci. USA, 88:5611-5 (1991)), and the neuron- specific vgf gene promoter (Piccioli et al, Neuron, 15:373-84 (1995)). In some embodiments, the tissue- specific promoter is a promoter of a gene selected from: neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP), adenomatous polyposis coli (APC), and ionized calcium-binding adapter molecule 1 (Iba- 1). Other appropriate tissue specific promoters will be apparent to the skilled artisan. In some embodiments, the promoter is a chicken Beta-actin promoter.

[0225] The present invention contemplates the use of a recombinant viral genome for introduction of one or more nucleic acid sequences (e.g., a guide RNA and/or a nucleotide sequence encoding a Cas protein) for packaging into a viral particle, e.g., a viral particle described below. The recombinant viral genome may include any element to establish the expression of the guide RNA and/or nucleotide sequence encoding a Cas protein, for example, a promoter, an ITR, a ribosome binding element, terminator, enhancer, selection marker, intron, polyA signal, and/or origin of replication. Exemplary viral genome elements and delivery methods for a range of viral particles are described in greater detail below.

Non-viral Delivery Systems

[0226] Conventional non- viral gene transfer methods may also be used to introduce nucleic acids into cells or target tissues. Non-viral vector delivery systems include DNA plasmids, RNA (e.g., a guide RNA or a nucleotide sequence encoding a Cas protein), naked nucleic acid (e.g., DNA or RNA), and nucleic acid (e.g., DNA or RNA) complexed to a delivery system. For example, the vector may be complexed to a lipid (e.g., a cationic or neutral lipid), a liposome, a polycation, a nanoparticle, or an agent that enhances the cellular uptake of nucleic acid. The vector may be complexed to an agent suitable for any of the delivery methods described herein.

[0227] Methods of non-viral delivery of nucleic acids include lipofection, nucleofection, microinjection, biolistics, nanoparticles (see, e.g., Jin, S. et al. (2009) Methods Mol. Biol. 544:547-557), virosomes, liposomes, immunoliposomes, polycation or lipid:nucleic acid conjugates, naked DNA, artificial virions, and agent-enhanced uptake of DNA. Lipofection is described in e.g., U.S. Pat. Nos. 5,049,386, 4,946,787; and 4,897,355) and lipofection reagents are sold commercially (e.g., Lipofectamine®, Transfectam™, and Lipofectin™). Cationic and neutral lipids that are suitable for efficient receptor-recognition lipofection of polynucleotides include those of Feigner, WO 91/17424; WO 91/16024. [0228] The preparation of lipid:nucleic acid complexes, including targeted liposomes such as immunolipid complexes, is well known to one of skill in the art (see, e.g., Crystal, Science 270:404-410 (1995); Blaese et al., Cancer Gene Ther. 2:291-297 (1995): Behr et al.,

Bioconjugate Chem. 5:382-389 (1994); Remy et al., Bioconjugate Chem. 5:647-654 (1994); Gao et al., Gene Therapy 2:710-722 (1995); Ahmad et al., Cancer Res. 52:4817-4820 (1992); U.S. Pat. Nos. 4,186,183, 4,217,344, 4,235,871, 4,261,975, 4,485,054, 4,501,728, 4,774,085, 4,837,028, and 4,946,787).

[0229] Other compounds that may be complexed with a vector of the present disclosure include without limitation a cationic peptide (e.g., poly-L-lysine), a salt (e.g., calcium phosphate), DEAE dextran, a dendrimer (e.g., polyamidoamine or PAMAM), polyethylene glycol, polyethylenimine (PEI) and conjugates thereof, and the like. For a more detailed discussion of such agents, see, e.g., Luo, D. and Saltzman, W.M. (2000) Nature

Biotechnology 18:33-37.'

[0230] In some embodiments, the nucleic acid is in a pharmaceutical formulation. In some embodiments, the pharmaceutical formulation includes a pharmaceutically acceptable carrier. Such carriers are well known in the art (see, e.g., Remington's Pharmaceutical Sciences, 15th Edition, pp. 1035-1038 and 1570-1580). In some embodiments, the pharmaceutical compositions comprising a nucleic acid described herein and a pharmaceutically acceptable carrier is suitable for ocular injection. Such pharmaceutically acceptable carriers can be sterile liquids, such as water and oil, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, and the like. Saline solutions and aqueous dextrose, polyethylene glycol (PEG) and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. The pharmaceutical composition may further comprise additional ingredients, for example preservatives, buffers, tonicity agents, antioxidants and stabilizers, nonionic wetting or clarifying agents, viscosity- increasing agents, and the like. The pharmaceutical compositions described herein can be packaged in single unit dosages or in multidosage forms. The compositions are generally formulated as sterile and substantially isotonic solution.

Viral Particles [0231] In some embodiments, the vector is a recombinant adeno-associated virus (rAAV) vector, a recombinant adenoviral vector, a recombinant lentiviral vector or a recombinant herpes simplex virus (HSV) vector. rAAV particles

[0232] In some embodiments, the vector is a recombinant AAV (rAAV) vector. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by one or more AAV inverted terminal repeat (ITR) sequences. In some embodiments, the viral particle is a recombinant AAV particle comprising a nucleic acid comprising a transgene flanked by one or two ITRs. In some embodiments, the nucleic acid encoding one of more of the first guide RNA, the second guide RNA, or the Cas protein is flanked by two AAV ITRs.

[0233] In some embodiments, the nucleic acid comprises one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure operatively linked components in the direction of transcription, control sequences including transcription initiation and termination sequences, thereby forming an expression cassette. The expression cassette is flanked on the 5' and 3' end by at least one functional AAV ITR sequence. By "functional AAV ITR sequences" it is meant that the ITR sequences function as intended for the rescue, replication and packaging of the AAV virion. See Davidson et al., PNAS, 2000, 97(7)3428-32; Passini et al., J. Virol., 2003, 77(12):7034-40; and Pechan et al, Gene Ther., 2009, 16: 10-16, all of which are incorporated herein in their entirety by reference. For practicing some aspects of the invention, the recombinant vectors comprise at least all of the sequences of AAV essential for encapsidation and the physical structures for infection by the rAAV. AAV ITRs for use in the vectors of the invention need not have a wild-type nucleotide sequence (e.g., as described in Kotin, Hum. Gene Ther., 1994, 5:793-801), and may be altered by the insertion, deletion or substitution of nucleotides or the AAV ITRs may be derived from any of several AAV serotypes. More than 40 serotypes of AAV are currently known, and new serotypes and variants of existing serotypes continue to be identified. See Gao et al, PNAS, 2002, 99(18): 11854-6; Gao et al, PNAS, 2003, 100(10):6081-6; and Bossis et al, J. Virol, 2003, 77(12):6799-810.

[0234] Use of any AAV serotype is considered within the scope of the present invention. In some embodiments, a rAAV vector is a vector derived from an AAV serotype, including without limitation, AAV ITRs are AAVl, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAV11, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV ITRs or the like. In some embodiments, the nucleic acid in the AAV comprises an ITR of AAV ITRs are AAVl, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, AAVrhlO, AAVl 1, AAV 12, AAV2R471A, AAV DJ, a goat AAV, bovine AAV, or mouse AAV or the like. In certain embodiments, the AAV ITRs are AAV2 ITRs.

[0235] In some embodiments, a vector may include a stuffer nucleic acid. In some embodiments, the stuffer nucleic acid may encode a green fluorescent protein. In some embodiments, the stuffer nucleic acid may be located between the promoter and the one or more of the one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure.

[0236] In some aspects, the invention provides viral particles comprising a recombinant self-complementing genome. In some embodiments, the vector is a self-complementary vector. AAV viral particles with self-complementing genomes and methods of use of self- complementing AAV genomes are described in US Patent Nos. 6,596,535; 7, 125,717;

7,765,583; 7,785,888; 7,790, 154; 7,846,729; 8,093,054; and 8,361,457; and Wang Z., et ah, (2003) Gene Ther 10:2105-2111, each of which are incorporated herein by reference in its entirety. A rAAV comprising a self-complementing genome will quickly form a double stranded DNA molecule by virtue of its partially complementing sequences (e.g.,

complementing coding and non-coding strands of a transgene). In some embodiments, the invention provides an AAV viral particle comprising an AAV genome, wherein the rAAV genome comprises a first heterologous polynucleotide sequence (e.g., one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure) and a second heterologous polynucleotide sequence (e.g., the noncoding or antisense strand of the one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure) wherein the first heterologous polynucleotide sequence can form intrastrand base pairs with the second polynucleotide sequence along most or all of its length.

[0237] In some embodiments, the first heterologous polynucleotide sequence and a second heterologous polynucleotide sequence are linked by a sequence that facilitates intrastrand basepairing; e.g., a hairpin DNA structure. Hairpin structures are known in the art, for example in siRNA molecules. In some embodiments, the first heterologous polynucleotide sequence and a second heterologous polynucleotide sequence are linked by a mutated ITR (e.g., the right ITR). The mutated ITR comprises a deletion of the D region comprising the terminal resolution sequence. As a result, on replicating an AAV viral genome, the rep proteins will not cleave the viral genome at the mutated ITR and as such, a recombinant viral genome comprising the following in 5' to 3' order will be packaged in a viral capsid: an AAV ITR, the first heterologous polynucleotide sequence including regulatory sequences, the mutated AAV ITR, the second heterologous polynucleotide in reverse orientation to the first heterologous polynucleotide and a third AAV ITR.

[0238] In some embodiments, the first heterologous nucleic acid sequence and a second heterologous nucleic acid sequence are linked by a mutated ITR (e.g., the right ITR). In some embodiments, the ITR comprises the polynucleotide sequence 5'- CACTCCCTCTCTGCGCGCTCGCTCGCTCACTGAGGCCGGGCGACCAAAGGTCGCC CACGCCCGGGCTTTGCCCGGGCG - 3' (SEQ ID NO:24). The mutated ITR comprises a deletion of the D region comprising the terminal resolution sequence. As a result, on replicating an AAV viral genome, the rep proteins will not cleave the viral genome at the mutated ITR and as such, a recombinant viral genome comprising the following in 5' to 3' order will be packaged in a viral capsid: an AAV ITR, the first heterologous polynucleotide sequence including regulatory sequences, the mutated AAV ITR, the second heterologous polynucleotide in reverse orientation to the first heterologous polynucleotide and a third AAV ITR.

[0239] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant AAV viral particle comprising a

recombinant AAV vector. Different AAV serotypes are used to optimize transduction of particular target cells or to target specific cell types within a particular target tissue (e.g. , an ocular tissue). A rAAV particle can comprise viral proteins and viral nucleic acids of the same serotype or a mixed serotype. For example, in some embodiments a rAAV particle can comprise AAV2 capsid proteins of the invention and at least one AAV2 ITR or it can comprise AAV2 capsid proteins and at least one AAV1 ITR. Any combination of AAV serotypes for production of a rAAV particle is provided herein as if each combination had been expressly stated herein. In some embodiments, the invention provides rAAV particles comprising an AAV2 capsid of the invention. In some embodiments, the invention provides rAAV particles comprising an AAVrh8R capsid of the invention.

[0240] In some embodiments, the rAAV particles comprise an AAV1 capsid, an AAV2 capsid, an AAV3 capsid, an AAV4 capsid, an AAV5 capsid, an AAV6 capsid (e.g., a wild- type AAV6 capsid, or a variant AAV6 capsid such as ShHIO, as described in U.S. PG Pub. 2012/0164106), an AAV7 capsid, an AAV8 capsid, an AAVrh8 capsid, an AAVrh8R capsid, an AAV9 capsid (e.g., a wild-type AAV9 capsid, or a modified AAV9 capsid as described in U.S. PG Pub. 2013/0323226), an AAV10 capsid, an AAVrhlO capsid, an AAV11 capsid, an AAV12 capsid, a tyrosine capsid mutant, a heparin binding capsid mutant, an AAV2R471A capsid, an AAVAAV2/2-7m8 capsid, an AAV DJ capsid (e.g., an AAV-DJ/8 capsid, an AAV-DJ/9 capsid, or any other of the capsids described in U.S. PG Pub. 2012/0066783), an AAV2 N587A capsid, an AAV2 E548A capsid, an AAV2 N708A capsid, an AAV V708K capsid, a goat AAV capsid, an AAV1/AAV2 chimeric capsid, a bovine AAV capsid, a mouse AAV capsid, a rAAV2/HBoVl capsid, or an AAV capsid described in U.S. Pat. No.

8,283, 151 or International Publication No. WO/2003/042397. In some embodiments, a mutant capsid protein maintains the ability to form an AAV capsid. In some embodiments, the rAAV particle comprises AAV5 tyrosine mutant capsid (Zhong L. et ah , (2008) Proc Natl Acad Sci U S A 105(22):7827-7832. In further embodiments, the rAAV particle comprises capsid proteins of an AAV serotype from Clades A-F (Gao, et ah, J. Virol. 2004, 78(12):6381). In some embodiments, the rAAV particle comprises an AAV1 capsid protein or mutant thereof. In other embodiments, the rAAV particle comprises an AAV2 capsid protein or mutant thereof. In some embodiments, the AAV serotype is AAV1, AAV2, AAV5, AAV6, AAV7, AAV8, AAVrh8, AAVrh8R, AAV9, AAV10, or AAVrhlO. In some embodiments, the rAAV particle comprises an AAV serotype 1 (AAV1) capsid. In some embodiments, the rAAV particle comprises an AAV serotype 2 (AAV2) capsid. In some embodiments, the recombinant AAV viral particle comprises an AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid. In some embodiments, the AAV1, AAV2, AAV8, AAVrh8R, AAV9, and/or AAVrhlO capsid comprises a tyrosine mutation or a heparan binding mutation, e.g., as described below.

[0241] The capsid of AAV (e.g. , AAV2, AAVrh8R, etc.) is known to include three capsid proteins: VP1, VP2, and VP3. These proteins contain significant amounts of overlapping amino acid sequence and unique N-terminal sequences. An AAV2 capsid includes 60 subunits arranged by icosahedral symmetry (Xie, Q., et al. (2002) Proc. Natl. Acad. Sci. 99(16): 10405-10). VP1, VP2, and VP3 have been found to be present in a 1: 1: 10 ratio.

[0242] The binding between AAV2 capsid proteins and HSPG is known to occur via electrostatic interactions between basic AAV2 capsid protein residues and negatively charged glycosaminoglycan residues (Opie, SR et al., (2003) J. Virol. 77:6995-7006; Kern, A et al., (2003) J. Virol. 77: 11072-11081). Specific capsid residues implicated in these interactions include R484, R487, K532, R585, and R588. Mutations in these residues have been shown to reduce AAV2 binding to Hela cells and heparan itself (Opie, SR et al., (2003) J. Virol.

77:6995-7006; Kern, A et al., (2003) J. Virol. 77: 11072-11081; WO 2004/027019 A2, US Patent No. 7,629,322). Further, without wishing to be bound to theory, it is thought that amino acid substitution(s) at one or more of the residues corresponding to amino acids 484, 487, 532, 585 or 588, numbering based on VP1 numbering of AAV2 may modulate the transduction properties of AAV capsid types that do not bind to HSPG, or may modulate the transduction properties of AAV capsid types independent from their ability to bind HSPG.

[0243] In some embodiments, a rAAV particle bears a mutation in a capsid protein at a residue that interacts with HSPG or at one or more of the residues corresponding to amino acids 484, 487, 532, 585 or 588, numbering based on VP1 numbering of AAV2.

Accordingly, in some embodiments, upon delivery the heterologous nucleic acid encoded by the rAAV vector is expressed at an increased level of expression, as compared to the level of expression of a heterologous nucleic acid of a rAAV particle comprising a rAAV capsid comprising a reference rAAV capsid protein (e.g., a wild-type rAAV capsid protein). In some embodiments, the expression of the nucleic acid is increased by at least about 10%, at least about 25%, at least about 50%, at least about 75%, or at least about 100%. In some embodiments, upon delivery the rAAV particle causes reduced neuroinflammation, as compared to a rAAV particle comprising a reference rAAV capsid protein (e.g., a wild-type rAAV capsid protein). In some embodiments, the neuroinflammation is reduced by at least about 10%, at least about 25%, at least about 50%, at least about 75%, or at least about 100%. A suitable reference rAAV capsid protein may include any capsid protein that lacks one or more amino acid substitutions at one or more positions that interact with a heparan sulfate proteoglycan (the reference capsid may thus contain one or more "background" substitutions that do not alter binding to HSPG). [0244] In some embodiments, the rAAV particle comprises a) a rAAV capsid comprising rAAV capsid proteins comprising one or more amino acid substitutions at one or more positions that interacts with a heparan sulfate proteoglycan, and b) a rAAV vector comprising the heterologous nucleic acid and at least one AAV inverted terminal repeat.

[0245] In some embodiments, the one or more amino acid substitutions reduce binding of the rAAV particle to the heparan sulfate proteoglycan by about at least 10%, about at least 25%, about at least 50%, about at least 75%, or about at least 100%. In some embodiments, the one or more amino acid substitutions reduce binding of the rAAV particle to the heparan sulfate proteoglycan by about at least 10%, about at least 15%, about at least 20%, about at least 25%, about at least 30%, about at least 35%, about at least 40%, about at least 45%, about at least 50%, about at least 55%, about at least 60%, about at least 65%, about at least 70%, about at least 75%, about at least 80%, about at least 85%, about at least 90%, about at least 95%, or about at least 100% (as compared to binding of a rAAV particle comprising a wild-type capsid). In some embodiments, the one or more amino acid substitutions reduce binding of the rAAV particle to the heparan sulfate proteoglycan by any one of about 10% to about 100%, about 20% to about 100%, about 30% to about 100%, about 40% to about 100%, about 50% to about 100%, about 60% to about 100%, about 70% to about 100%, about 80% to about 100%, about 90% to about 100%, about 10% to about 90%, about 20% to about 90%, about 30% to about 90%, about 40% to about 90%, about 50% to about 90%, about 60% to about 90%, about 70% to about 90%, about 80% to about 90%, about 10% to about 80%, about 20% to about 80%, about 30% to about 80%, about 40% to about 80%, about 50% to about 80%, about 60% to about 80%, about 70% to about 80%, about 10% to about 70%, about 20% to about 70%, about 30% to about 70%, about 40% to about 70%, about 50% to about 70%, about 60% to about 70%, about 10% to about 60%, about 20% to about 60%, about 30% to about 60%, about 40% to about 60%, about 50% to about 60%, about 10% to about 50%, about 20% to about 50%, about 30% to about 50%, about 40% to about 50%, about 10% to about 40%, about 20% to about 40%, about 30% to about 40%, about 10% to about 30%, about 20% to about 30%, or about 10% to about 20%, (as compared to binding of a rAAV particle comprising a wild-type capsid). In some

embodiments, the one or more amino acid substitutions results in no detectable binding of the rAAV particle to the heparan sulfate proteoglycan compared to binding of a wild-type rAAV particle. Means to measure binding of AAV particles to HSPG are known in the art; e.g. , binding to a heparan sulfate chromatography media or binding to a cell known to express HSPG on its surface. For example, see Opie, SR et al, (2003) J. Virol. 77:6995-7006 and Kern, A et al, (2003) J. Virol. 77: 11072-11081.

[0246] In some embodiments, the rAAV particles comprise one or more amino acid substitutions of capsid proteins that reduce or ablate binding of the rAAV particle to the heparan sulfate proteoglycan, and/or wherein the one or more amino acid substitutions is at position 484, 487, 532, 585 or 588, numbering based on VPl numbering of AAV2. As used herein, "numbering based on VPl of AAV2" refers to the amino acid of the recited capsid protein corresponding to the recited amino acid of VPl of AAV2. For example, if one or more amino acid substitutions are at position 347, 350, 390, 395, 448, 451, 484, 487, 527, 532, 585 and/or 588, numbering based on VPl of AAV2, then the one or more amino acid substitutions are at the amino acid(s) of the recited capsid protein corresponding to amino acids 347, 350, 390, 395, 448, 451, 484, 487, 527, 532, 585 and/or 588 of VPl of AAV2. In some embodiments, the one or more amino acid substitutions is at position 484, 487, 532, 585 or 588 of VPl of AAV2. In some embodiments, the one or more amino acid

substitutions is at position 484, 487, 532, 585 or 588 of VPl of AAV3, numbering based on VPl of AAV2. In some embodiments, the one or more amino acid substitutions is at position 485, 488, 528, 533, 586 or 589, numbering based on VPl numbering of AAVrh8R. In some embodiments, one or more amino acids at position(s) corresponding to amino acids 585 and/or 588 (numbering based on VPl of AAV2) are replaced by arginine residues (e.g., S586 and/or T589 for AAV1 or AAV6; S586 and/or A589 for AAV9; A586 and/or T589 for AAVrh8R; Q588 and/or T591 for AAV8; and Q588 and/or A591 for AAVrhlO). In other embodiments, one or more amino acids (e.g., arginine or lysine) at position(s) corresponding to amino acids 484, 487, 527 and/or 532 (numbering based on VPl of AAV2) are replaced by non-positively charged amino acid(s) such as alanine (e.g., R485, R488, K528, and/or K533 for AAV1 or AAV6; R485, R488, K528, and/or R533 for AAV9 or AAVrh8R; and R487, R490, K530, and/or R535 for AAV8 or AAVrhlO).

Other viral particles

[0247] In some embodiments, the vector is a recombinant adenoviral vector. In some embodiments, the viral particle is an adenoviral particle. In some embodiments, the adenoviral particle is a recombinant adenoviral particle, e.g., a polynucleotide vector comprising one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure between two ITRs. In some embodiments, the adenoviral particle lacks or contains a defective copy of one or more El genes, which renders the adenovirus replication-defective. Adenoviruses include a linear, double- stranded DNA genome within a large (-950A), non-enveloped icosahedral capsid. Adenoviruses have a large genome that can incorporate more than 30kb of heterologous sequence (e.g., in place of the El and/or E3 region), making them uniquely suited for use with larger heterologous genes. They are also known to infect dividing and non-dividing cells and do not naturally integrate into the host genome (although hybrid variants may possess this ability). In some embodiments, the adenoviral vector may be a first generation adenoviral vector with a heterologous sequence in place of El. In some embodiments, the adenoviral vector may be a second generation adenoviral vector with additional mutations or deletions in E2A, E2B, and/or E4. In some embodiments, the adenoviral vector may be a third generation or gutted adenoviral vector that lacks all viral coding genes, retaining only the ITRs and packaging signal and requiring a helper adenovirus in trans for replication, and packaging. Adenoviral particles have been investigated for use as vectors for transient transfection of mammalian cells as well as gene therapy vectors. For further description, see, e.g., Danthinne, X. and Imperiale, M.J. (2000) Gene Ther. 7: 1707-14 and Tatsis, N. and Ertl, H.C. (2004) Mol. Ther. 10:616-29.

[0248] In some embodiments, the viral particle is a recombinant adenoviral particle comprising a nucleic acid comprising one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure. Use of any adenovirus serotype is considered within the scope of the present invention. In some embodiments, the recombinant adenoviral vector is a vector derived from an adenovirus serotype, including without limitation, Adenovirus serotype 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenoviral vector is derived from adenovirus serotype 2 or a variant of adenoviral serotype 5.

[0249] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant adenovirus particle encapsidating a recombinant adenoviral vector. In some embodiments, the recombinant viral particles comprise an adenoviral particle in combination with one or more foreign viral capsid proteins. Such combinations may be referred to as pseudotyped recombinant adenoviral particles. In some embodiments, foreign viral capsid proteins used in pseudotyped recombinant adenoviral particles are derived from a foreign virus or from another adenovirus serotype. In some embodiments, the foreign viral capsid proteins are derived from, including without limitation, reovirus type 3. Examples of vector and capsid protein combinations used in pseudotyped adenovirus particles can be found in the following references (Tatsis, N. et al. (2004) Mol. Ther. 10(4):616-629 and Ahi, Y. et al. (2011) Curr. Gene Ther. l l(4):307-320). Different adenovirus serotypes can be used to optimize transduction of particular target cells or to target specific cell types within a particular target tissue {e.g., a diseased tissue).

Tissues or cells targeted by specific adenovirus serotypes, include without limitation, lung {e.g. HuAd3), spleen and liver {e.g. HuAd37), smooth muscle, synoviocytes, dendritic cells, cardiovascular cells, tumor cell lines {e.g. HuAdl 1), and dendritic cells {e.g. HuAd5 pseudotyped with reovirus type 3, HuAd30, or HuAd35). For further description, see Ahi, Y. et al. (2011) Curr. Gene Ther. l l(4):307-320, Kay, M. et al. (2001) Nat. Med. 7(l):33-40, and Tatsis, N. et al. (2004) Mol. Ther. 10(4):616-629. In some embodiments, the

recombinant adenovirus particle may contain a capsid from an Adenovirus serotype including without limitation 2, 1, 5, 6, 19, 3, 11, 7, 14, 16, 21, 12, 18, 31, 8, 9, 10, 13, 15, 17, 19, 20, 22, 23, 24-30, 37, 40, 41, AdHu2, AdHu 3, AdHu4, AdHu24, AdHu26, AdHu34, AdHu35, AdHu36, AdHu37, AdHu41, AdHu48, AdHu49, AdHu50, AdC6, AdC7, AdC69, bovine Ad type 3, canine Ad type 2, ovine Ad, or porcine Ad type 3. In some embodiments, the recombinant adenovirus particle comprises an adenovirus serotype 2 capsid or a variant of an adenoviral serotype 5 capsid.

[0250] In some embodiments, the vector is a recombinant lentiviral vector. In some embodiments, the viral particle is a lentiviral particle. In some embodiments, the lentiviral particle is a recombinant lentiviral particle, e.g., a polynucleotide vector comprising one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure between two LTRs. Lentiviruses are positive-sense, ssRNA retroviruses with a genome of approximately 10 kb. Lentiviruses are known to integrate into the genome of dividing and non-dividing cells. Lentiviral particles may be produced, for example, by transfecting multiple plasmids (typically the lentiviral genome and the genes required for replication and/or packaging are separated to prevent viral replication) into a packaging cell line, which packages the modified lentiviral genome into lentiviral particles. In some embodiments, a lentiviral particle may refer to a first generation vector that lacks the envelope protein. In some embodiments, a lentiviral particle may refer to a second generation vector that lacks all genes except the gag/pol and tat/rev regions. In some embodiments, a lentiviral particle may refer to a third generation vector that only contains the endogenous rev, gag, and pol genes and has a chimeric LTR for transduction without the tat gene (see Dull, T. et al. (1998) J. Virol. 72:8463-71). For further description, see Durand, S. and Cimarelli, A. (2011) Viruses 3: 132-59.

[0251] In some embodiments, the viral particle is a recombinant lentiviral particle comprising a nucleic acid comprising one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure. Use of any lentiviral vector is considered within the scope of the present invention. In some embodiments, the lentiviral vector is derived from a lentivirus including, without limitation, human

immunodeficiency virus- 1 (HIV-1), human immunodeficiency virus-2 (HIV-2), simian immunodeficiency virus (SIV), feline immunodeficiency virus (FIV), equine infectious anemia virus (EIAV), bovine immunodeficiency virus (BIV), Jembrana disease virus (JDV), visna virus (VV), and caprine arthritis encephalitis virus (CAEV).

[0252] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant lentiviral particle encapsidating a

recombinant lentiviral vector. In some embodiments, the recombinant viral particles comprise a lentivirus vector in combination with one or more foreign viral capsid proteins. Such combinations may be referred to as pseudotyped recombinant lentiviral particles. In some embodiments, foreign viral capsid proteins used in pseudotyped recombinant lentiviral particles are derived from a foreign virus. In some embodiments, the foreign viral capsid protein used in pseudotyped recombinant lentiviral particles is Vesicular stomatitis virus glycoprotein (VSV-GP). VSV-GP interacts with a ubiquitous cell receptor, providing broad tissue tropism to pseudotyped recombinant lentiviral particles. In addition, VSV-GP is thought to provide higher stability to pseudotyped recombinant lentiviral particles. In other embodiments, the foreign viral capsid proteins are derived from, including without limitation, Chandipura virus, Rabies virus, Mokola virus, Lymphocytic choriomeningitis virus (LCMV), Ross River virus (RRV), Sindbis virus, Semliki Forest virus (SFV), Venezuelan equine encephalitis virus, Ebola virus Reston, Ebola virus Zaire, Marburg virus, Lassa virus, Avian leukosis virus (ALV), Jaagsiekte sheep retrovirus (JSRV), Moloney Murine leukemia virus (MLV), Gibbon ape leukemia virus (GALV), Feline endogenous retrovirus (RD114), Human T-lymphotropic virus 1 (HTLV-1), Human foamy virus, Maedi-visna virus (MVV), SARS- CoV, Sendai virus, Respiratory syncytia virus (RSV), Human parainfluenza virus type 3, Hepatitis C virus (HCV), Influenza virus, Fowl plague virus (FPV), or Autographa californica multiple nucleopolyhedro virus (AcMNPV).

[0253] In some embodiments, the recombinant lentiviral vector is derived from a lentivirus pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RDl 14, or variants therein. Examples of vector and capsid protein combinations used in pseudotyped Lentivirus particles can be found, for example, in Cronin, J. et al. (2005). Curr. Gene Ther. 5(4):387-398. Different pseudotyped recombinant lentiviral particles can be used to optimize transduction of particular target cells or to target specific cell types within a particular target tissue (e.g. , a diseased tissue). For example, tissues targeted by specific pseudotyped recombinant lentiviral particles, include without limitation, liver (e.g.

pseudotyped with a VSV-G, LCMV, RRV, or SeV F protein), lung (e.g. pseudotyped with an Ebola, Marburg, SeV F and HN, or JSRV protein), pancreatic islet cells (e.g. pseudotyped with an LCMV protein), central nervous system (e.g. pseudotyped with a VSV-G, LCMV, Rabies, or Mokola protein), retina (e.g. pseudotyped with a VSV-G or Mokola protein), monocytes or muscle (e.g. pseudotyped with a Mokola or Ebola protein), hematopoietic system (e.g. pseudotyped with an RDl 14 or GALV protein), or cancer cells (e.g. pseudotyped with a GALV or LCMV protein). For further description, see Cronin, J. et al. (2005). Curr. Gene Ther. 5(4):387-398 and Kay, M. et al. (2001) Nat. Med. 7(l):33-40. In some embodiments, the recombinant lentiviral particle comprises a capsid pseudotyped with vesicular stomatitis virus (VSV), lymphocytic choriomeningitis virus (LCMV), Ross river virus (RRV), Ebola virus, Marburg virus, Mokala virus, Rabies virus, RD l 14 or variants therein.

[0254] In some embodiments, the vector is an rHSV vector. In some embodiments, the viral particle is a herpes simplex virus (HSV) particle. In some embodiments, the HSV particle is a rHSV particle, e.g., a polynucleotide vector comprising one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure between two TRs. HSV is an enveloped, double-stranded DNA virus with a genome of approximately 152 kb. Advantageously, approximately half of its genes are nonessential and may be deleted to accommodate heterologous sequence. HSV particles infect non-dividing cells. In addition, they naturally establish latency in neurons, travel by retrograde transport, and can be transferred across synapses, making them advantageous for transfection of neurons and/or gene therapy approaches involving the nervous system. In some embodiments, the HSV particle may be replication-defective or replication-competent (e.g., competent for a single replication cycle through inactivation of one or more late genes). For further description, see Manservigi, R. et al. (2010) Open Virol. J. 4: 123-56.

[0255] In some embodiments, the viral particle is a rHSV particle comprising a nucleic acid comprising one or two guide RNAs of the present disclosure and/or a nucleotide sequence encoding a Cas protein of the present disclosure. Use of any HSV vector is considered within the scope of the present invention. In some embodiments, the HSV vector is derived from a HSV serotype, including without limitation, HSV-1 and HSV-2.

[0256] In some embodiments, the vector is encapsidated in a viral particle. In some embodiments, the viral particle is a recombinant HSV particle encapsidating a recombinant HSV vector. In some embodiments, the recombinant viral particles comprise a HSV vector in combination with one or more foreign viral capsid proteins. Such combinations may be referred to as pseudotyped rHSV particles. In some embodiments, foreign viral capsid proteins used in pseudotyped rHSV particles are derived from a foreign virus or from another HSV serotype. In some embodiments, the foreign viral capsid protein used in a pseudotyped rHSV particle is a Vesicular stomatitis virus glycoprotein (VSV-GP). VSV-GP interacts with a ubiquitous cell receptor, providing broad tissue tropism to pseudotyped rHSV particles. In addition, VSV-GP is thought to provide higher stability to pseudotyped rHSV particles. In other embodiments, the foreign viral capsid protein may be from a different HSV serotype. For example, an HSV-1 vector may contain one or more HSV-2 capsid proteins. Different HSV serotypes can be used to optimize transduction of particular target cells or to target specific cell types within a particular target tissue (e.g., a diseased tissue). Tissues or cells targeted by specific adenovirus serotypes include without limitation, central nervous system and neurons (e.g. HSV-1). For further description, see Manservigi, R. et al. (2010) Open Virol J 4: 123-156, Kay, M. et al. (2001) Nat. Med. 7(l):33-40, and Meignier, B. et al. (1987) J. Infect. Dis. 155(5):921-930. In some embodiments, the recombinant HSV particle is an rHSV-1 particle or an rHSV-2 viral particle. Production of viral particles

[0257] Numerous methods are known in the art for production of adenoviral vector particles. For example, for a gutted adenoviral vector, the adenoviral vector genome and a helper adenovirus genome may be transfected into a packaging cell line (e.g., a 293 cell line). In some embodiments, the helper adenovirus genome may contain recombination sites flanking its packaging signal, and both genomes may be transfected into a packaging cell line that expresses a recombinase (e.g., the Cre/loxP system may be used), such that the adenoviral vector of interest is packaged more efficiently than the helper adenovirus (see, e.g., Alba, R. et al. (2005) Gene Ther. 12 Suppl l:S 18-27). Adenoviral vectors may be harvested and purified using standard methods, such as those described herein.

[0258] Numerous methods are known in the art for production of lentiviral vector particles. For example, for a third-generation lentiviral vector, a vector containing the lentiviral genome of interest with gag and pol genes may be co-transfected into a packaging cell line (e.g., a 293 cell line) along with a vector containing a rev gene. The lentiviral genome of interest also contains a chimeric LTR that promotes transcription in the absence of Tat (see Dull, T. et al. (1998) J. Virol. 72:8463-71). Lentiviral vectors may be harvested and purified using methods (e.g., Segura MM, et al, (2013) Expert Opin Biol Ther. 13(7):987- 1011) described herein.

[0259] Numerous methods are known in the art for production of HSV particles. HSV vectors may be harvested and purified using standard methods, such as those described herein. For example, for a replication-defective HSV vector, an HSV genome of interest that lacks all of the immediate early (IE) genes may be transfected into a complementing cell line that provides genes required for virus production, such as ICP4, ICP27, and ICP0 (see, e.g., Samaniego, L.A. et al. (1998) J. Virol. 72:3307-20). HSV vectors may be harvested and purified using methods described (e.g., Goins, WF et al., (2014) Herpes Simplex Virus Methods in Molecular Biology 1144:63-79).

[0260] Numerous methods are known in the art for production of rAAV vectors, including transfection, stable cell line production, and infectious hybrid virus production systems which include adenovirus-AAV hybrids, herpesvirus-AAV hybrids (Conway, JE et al., (1997) J. Virology 71(11):8780-8789) and baculovirus-AAV hybrids. rAAV production cultures for the production of rAAV virus particles all require; 1) suitable host cells, 2) suitable helper virus function, 3) AAV rep and cap genes and gene products; 4) a nucleic acid (such as a therapeutic nucleic acid) flanked by at least one AAV ITR sequences (e.g., an oversized rAAV vector genome); and 5) suitable media and media components to support rAAV production. In some embodiments, the suitable host cell is a primate host cell. In some embodiments, the suitable host cell is a human-derived cell lines such as HeLa, A549, 293, or Perc.6 cells. In some embodiments, the suitable helper virus function is provided by wild- type or mutant adenovirus (such as temperature sensitive adenovirus), herpes virus (HSV), baculovirus, or a plasmid construct providing helper functions. In some embodiments, the AAV rep and cap gene products may be from any AAV serotype. In general, but not obligatory, the AAV rep gene product is of the same serotype as the ITRs of the rAAV vector genome as long as the rep gene products may function to replicated and package the rAAV genome. Suitable media known in the art may be used for the production of rAAV vectors. These media include, without limitation, media produced by Hyclone Laboratories and JRH including Modified Eagle Medium (MEM), Dulbecco's Modified Eagle Medium (DMEM), custom formulations such as those described in U.S. Patent No. 6,566,118, and Sf-900 II SFM media as described in U.S. Patent No. 6,723,551, each of which is incorporated herein by reference in its entirety, particularly with respect to custom media formulations for use in production of recombinant AAV vectors. In some embodiments, the AAV helper functions are provided by adenovirus or HSV. In some embodiments, the AAV helper functions are provide by baculovirus and the host cell is an insect cell (e.g., Spodoptera frugiperda (Sf9) cells). Examples of adenovirus helper functions for the replication of AAV include E1A functions, E1B functions, E2A functions, VA functions and E4orf6 functions. Baculoviruses available from depositories include Autographa californica nuclear polyhedrosis virus.

[0261] The rAAV particles can be produced using methods known in the art. See, e.g., U.S. Pat. Nos. 6,566,118; 6,989,264; and 6,995,006. In practicing the invention, host cells for producing rAAV particles include mammalian cells, insect cells, plant cells,

microorganisms and yeast. Host cells can also be packaging cells in which the AAV rep and cap genes are stably maintained in the host cell or producer cells in which the AAV vector genome is stably maintained. Exemplary packaging and producer cells are derived from 293, A549 or HeLa cells. AAV vectors are purified and formulated using standard techniques known in the art.

[0262] In some embodiments, rAAV particles may be produced by a triple transfection method, such as the exemplary triple transfection method provided infra. Briefly, a plasmid containing a rep gene and a capsid gene, along with a helper adenoviral plasmid, may be transfected (e.g., using the calcium phosphate method) into a cell line (e.g., HEK-293 cells), and virus may be collected and optionally purified.

[0263] In some embodiments, rAAV particles may be produced by a producer cell line method (see, e.g., Martin et al., (2013) Human Gene Therapy Methods 24:253-269). Briefly, a cell line (e.g., a HeLa cell line) may be stably transfected with a plasmid containing a rep gene, a capsid gene, and a promoter-transgene sequence. Cell lines may be screened to select a lead clone for rAAV production, which may then be expanded to a production bioreactor and infected with an adenovirus (e.g., a wild-type adenovirus) as helper to initiate rAAV production. Virus may subsequently be harvested, adenovirus may be inactivated (e.g., by heat) and/or removed, and the rAAV particles may be purified. In some embodiments, the producer cell line is derived from HeLa, 293, A549, or Perc.6 cells. In some embodiments, the producer cell line is adapted for growth in suspension. In some embodiments, the AAV helper functions are provided by adenovirus, HSV or baculovirus.

[0264] In some embodiments, rAAV particles are collected from between about 48 hours and about 96 hours after the provision of helper functions. For example, in some

embodiments, rAAV particles are collected about 48 hours, about 60 hours, about 72 hours, about 84 hours, or about 96 hours after the provision of helper functions. In some embodiments, rAAV particles are collected about 48 hours and about 96 hours, about 48 hours and about 84 hours, about 48 hours and about 72 hours, about 48 hours and about 60 hours, about 60 hours and about 96 hours, about 60 hours and about 84 hours, about 60 hours and about 72 hours, about 72 hours and about 96 hours, about 72 hours and about 84 hours, or about 84 hours and about 96 hours after the provision of helper functions.

[0265] Suitable rAAV production culture media of the present invention may be supplemented with serum or serum-derived recombinant proteins at a level of 0.5%-20% (v/v or w/v). Alternatively, as is known in the art, rAAV vectors may be produced in serum- free conditions which may also be referred to as media with no animal-derived products. One of ordinary skill in the art may appreciate that commercial or custom media designed to support production of rAAV vectors may also be supplemented with one or more cell culture components known in the art, including without limitation glucose, vitamins, amino acids, and or growth factors, in order to increase the titer of rAAV in production cultures. [0266] rAAV production cultures can be grown under a variety of conditions (over a wide temperature range, for varying lengths of time, and the like) suitable to the particular host cell being utilized. As is known in the art, rAAV production cultures include attachment- dependent cultures which can be cultured in suitable attachment-dependent vessels such as, for example, roller bottles, hollow fiber filters, microcarriers, and packed-bed or fluidized- bed bioreactors. rAAV vector production cultures may also include suspension-adapted host cells such as HeLa, 293, and SF-9 cells which can be cultured in a variety of ways including, for example, spinner flasks, stirred tank bioreactors, and disposable systems such as the Wave bag system.

[0267] rAAV vector particles of the invention may be harvested from rAAV production cultures by lysis of the host cells of the production culture or by harvest of the spent media from the production culture, provided the cells are cultured under conditions known in the art to cause release of rAAV particles into the media from intact cells, as described more fully in U.S. Patent No. 6,566,118). Suitable methods of lysing cells are also known in the art and include for example multiple freeze/thaw cycles, sonication, microfluidization, and treatment with chemicals, such as detergents and/or proteases.

[0268] In a further embodiment, the viral particles are purified. The term "purified" as used herein includes a preparation of viral particles devoid of at least some of the other components that may also be present where the viral particles naturally occur or are initially prepared from. Thus, for example, isolated viral particles may be prepared using a purification technique to enrich it from a source mixture, such as a culture lysate or production culture supernatant. Enrichment can be measured in a variety of ways, such as, for example, by the proportion of DNase-resistant particles (DRPs) or genome copies (gc) present in a solution, or by infectivity, or it can be measured in relation to a second, potentially interfering substance present in the source mixture, such as contaminants, including production culture contaminants or in-process contaminants, including helper virus, media components, and the like.

[0269] In some embodiments, the viral production culture harvest is clarified to remove host cell debris. In some embodiments, the production culture harvest is clarified by filtration through a series of depth filters including, for example, a grade DOHC Millipore Millistak+ HC Pod Filter, a grade A1HC Millipore Millistak+ HC Pod Filter, and a 0.2 μιη Filter Opticap XLIO Millipore Express SHC Hydrophilic Membrane filter. Clarification can also be achieved by a variety of other standard techniques known in the art, such as, centrifugation or filtration through any cellulose acetate filter of 0.2 μηι or greater pore size known in the art.

[0270] In some embodiments, the viral production culture harvest is further treated with Benzonase ^® to digest any high molecular weight DNA present in the production culture. In some embodiments, the Benzonase ^® digestion is performed under standard conditions known in the art including, for example, a final concentration of 1-2.5 units/ml of Benzonase ^® at a temperature ranging from ambient to 37°C for a period of 30 minutes to several hours.

[0271] rAAV particles may be isolated or purified using one or more of the following purification steps: equilibrium centrifugation; flow-through anionic exchange filtration;

tangential flow filtration (TFF) for concentrating the rAAV particles; rAAV capture by apatite chromatography; heat inactivation of helper virus; rAAV capture by hydrophobic interaction chromatography; buffer exchange by size exclusion chromatography (SEC);

nanofiltration; and rAAV capture by anionic exchange chromatography, cationic exchange chromatography, or affinity chromatography. These steps may be used alone, in various combinations, or in different orders. Methods to purify rAAV particles are found, for example, in Xiao et al, (1998) Journal of Virology 72:2224-2232; US Patent Numbers 6,989,264 and 8,137,948; and WO 2010/148143. Methods to purify adenovirus particles are found, for example, in Bo, H et al., (2014) Eur. J. Pharm. Sci. 67C: 119-125. Methods to purify lentivirus particles are found, for example, in Segura MM, et al., (2013) Expert Opin Biol Ther. 13(7):987-1011. Methods to purify HSV particles are found, for example, in Goins, WF et al., (2014) Herpes Simplex Virus Methods in Molecular Biology 1144:63-79.

[0272] In some embodiments, the viral particle is in a pharmaceutical formulation. In some embodiments, the pharmaceutical formulation includes a pharmaceutically acceptable carrier. Such carriers are well known in the art (see, e.g., Remington's Pharmaceutical Sciences, 15th Edition, pp. 1035-1038 and 1570-1580). In some embodiments, the pharmaceutical compositions comprising a viral particle described herein and a pharmaceutically acceptable carrier is suitable for ocular injection. Such pharmaceutically acceptable carriers can be sterile liquids, such as water and oil, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, and the like. Saline solutions and aqueous dextrose, polyethylene glycol (PEG) and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. The pharmaceutical composition may further comprise additional ingredients, for example preservatives, buffers, tonicity agents, antioxidants and stabilizers, nonionic wetting or clarifying agents, viscosity- increasing agents, and the like. The pharmaceutical compositions described herein can be packaged in single unit dosages or in multidosage forms. The compositions are generally formulated as sterile and substantially isotonic solution.

VI. Methods of Treatment

[0273] Certain aspects of the present disclosure involve administering to an individual a therapeutically effective amount of a composition comprising a nucleic acid encoding an engineered, non-naturally occurring CRISPR-Cas system of the present disclosure, e.g., as described above.

[0274] In some embodiments, aspects of the present disclosure involve administering to an individual a therapeutically effective amount of a composition comprising a Cas protein of the present disclosure and one or more nucleic acid(s) comprising a first guide RNA and a second guide RNA wherein the first guide RNA and the second guide RNA hybridize to the opposite strands of the target DNA sequences flanking a mutation including a deep intronic mutation, e.g., as described above. That is to say, for any of the methods, compositions, and kits of the present disclosure, the Cas protein may be supplied as a nucleotide sequence encoding the Cas protein, or as a polypeptide. As a non-limiting example, a Cas protein may be administered with one or more guide RNAs (e.g., a sgRNA) using cationic lipid-mediated delivery (see, e.g., Zuris, J. A. et al. Nat Biotechnol. 33:73-80). In some embodiments, a Cas protein may be administered in a complex with one or more guide RNAs, e.g., as in a CRISPR-Cas effector complex. It will be appreciated that any of the delivery and/or administration methods described below may be used for delivery of a Cas protein administered with one or more guide RNAs. In some embodiments, the Cas protein is expressed from a self-limiting expression cassette as described above.

[0275] In some embodiments, the composition comprising a nucleic acid encoding an engineered, non-naturally occurring CRISPR-Cas system of the present disclosure (or a composition comprising a Cas protein of the present disclosure and one or more guide RNAs of the present disclosure) is administered intravenously, intramuscularly, subcutaneously, topically, orally, transdermally, intraperitoneally, intraorbitally, by implantation, by inhalation, intrathecally, intraventricularly, or intranasally. [0276] In some embodiments, the composition comprising a nucleic acid encoding an engineered, non-naturally occurring CRISPR-Cas system of the present disclosure (or a composition comprising a Cas protein of the present disclosure and one or more guide RNAs of the present disclosure) is administered subretinally or intravitreally. Gene therapy protocols for retinal diseases, such as ocular diseases associated with a deep intronic mutation, require the localized delivery of the nucleic acid to the cells in the retina. The cells that will be the treatment target in these diseases are either the photoreceptor cells in the retina or the cells of the RPE underlying the neurosensory retina. Delivering nucleic acids to these cells requires injection into the subretinal space between the retina and the RPE.

[0277] In some aspects, the invention provides compositions comprising any of the nucleic acids described herein, optionally in a pharmaceutically acceptable excipient. As is well known in the art, pharmaceutically acceptable excipients are relatively inert substances that facilitate administration of a pharmacologically effective substance and can be supplied as liquid solutions or suspensions, as emulsions, or as solid forms suitable for dissolution or suspension in liquid prior to use. For example, an excipient can give form or consistency, or act as a diluent. Suitable excipients include but are not limited to stabilizing agents, wetting and emulsifying agents, salts for varying osmolarity, encapsulating agents, pH buffering substances, and buffers. Such excipients include any pharmaceutical agent suitable for direct delivery to the eye which may be administered without undue toxicity. Pharmaceutically acceptable excipients include, but are not limited to, sorbitol, any of the various TWEEN compounds, and liquids such as water, saline, glycerol and ethanol. Pharmaceutically acceptable salts can be included therein, for example, mineral acid salts such as

hydrochlorides, hydrobromides, phosphates, sulfates, and the like; and the salts of organic acids such as acetates, propionates, malonates, benzoates, and the like. A thorough discussion of pharmaceutically acceptable excipients is available in REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Pub. Co., N.J. 1991).

[0278] Generally, these compositions are formulated for administration by subretinal injection. Accordingly, these compositions can be combined with pharmaceutically acceptable vehicles such as saline, Ringer's balanced salt solution (pH 7.4), and the like. Although not required, the compositions may optionally be supplied in unit dosage form suitable for administration of a precise amount. Methods of subretinal delivery

[0279] Methods of subretinal delivery are known in the art. For example, see WO

2009/105690, incorporated herein by reference. Briefly, the general method for delivering a composition (e.g., a nucleic acid encoding an engineered, non-naturally occurring CRISPR- Cas system of the present disclosure, which may be delivered through viral or non-viral delivery as described above) to the subretina of the macula and fovea may be illustrated by the following brief outline. This example is merely meant to illustrate certain features of the method, and is in no way meant to be limiting.

[0280] Generally, the vector can be delivered in the form of a composition injected intraocularly (subretinally) under direct observation using an operating microscope. This procedure may involve vitrectomy followed by injection of a vector suspension using a fine cannula through one or more small retinotomies into the subretinal space.

[0281] Briefly, an infusion cannula can be sutured in place to maintain a normal globe volume by infusion (of e.g., saline) throughout the operation. A vitrectomy is performed using a cannula of appropriate bore size (for example 20 to 27 gauge), wherein the volume of vitreous gel that is removed is replaced by infusion of saline or other isotonic solution from the infusion cannula. The vitrectomy is advantageously performed because (1) the removal of its cortex (the posterior hyaloid membrane) facilitates penetration of the retina by the cannula; (2) its removal and replacement with fluid (e.g., saline) creates space to

accommodate the intraocular injection of vector, and (3) its controlled removal reduces the possibility of retinal tears and unplanned retinal detachment.

[0282] In some embodiments, the vector composition is directly injected into the subretinal space outside the central retina, by utilizing a cannula of the appropriate bore size (e.g., 27-45 gauge), thus creating a bleb in the subretinal space. In other embodiments, the subretinal injection of the vector composition is preceded by subretinal injection of a small volume (e.g., about 0.1 to about 0.5 ml) of an appropriate fluid (such as saline or Ringer' s solution) into the subretinal space outside the central retina. This initial injection into the subretinal space establishes an initial fluid bleb within the subretinal space, causing localized retinal detachment at the location of the initial bleb. This initial fluid bleb can facilitate targeted delivery of the vector composition to the subretinal space (by defining the plane of injection prior to vector delivery), and minimize possible vector administration into the choroid and the possibility of injection or reflux into the vitreous cavity. In some embodiments, this initial fluid bleb can be further injected with fluids comprising one or more vector compositions and/or one or more additional therapeutic agents by administration of these fluids directly to the initial fluid bleb with either the same or additional fine bore cannulas.

[0283] Intraocular administration of the vector compositions and/or the initial small volume of fluid can be performed using a fine bore cannula (e.g., 27-45 gauge) attached to a syringe. In some embodiments, the plunger of this syringe may be driven by a mechanized device, such as by depression of a foot pedal. The fine bore cannula is advanced through the sclerotomy, across the vitreous cavity and into the retina at a site pre-determined in each subject according to the area of retina to be targeted (but outside the central retina). Under direct visualization the vector suspension is injected mechanically under the neurosensory retina causing a localized retinal detachment with a self-sealing non-expanding retinotomy. As noted above, the vector composition can be either directly injected into the subretinal space creating a bleb outside the central retina or the vector can be injected into an initial bleb outside the central retina, causing it to expand (and expanding the area of retinal detachment). In some embodiments, the injection of the vector composition is followed by injection of another fluid into the bleb.

[0284] Without wishing to be bound by theory, the rate and location of the subretinal injection(s) can result in localized shear forces that can damage the macula, fovea and/or underlying RPE cells. The subretinal injections may be performed at a rate that minimizes or avoids shear forces. In some embodiments, the vector composition is injected over about 15- 17 minutes. In some embodiments, the vector is injected over about 17-20 minutes. In some embodiments, the vector composition is injected over about 20-22 minutes. In some embodiments, the vector composition is injected at a rate of about 35 to about 65 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 35 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 40 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 45 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 50 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 55 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 60 μΐ/min. In some embodiments, the vector composition is injected at a rate of about 65 μΐ/min. One of ordinary skill in the art would recognize that the rate and time of injection of the bleb may be directed by, for example, the volume of the vector composition or size of the bleb necessary to create sufficient retinal detachment to access the cells of central retina, the size of the cannula used to deliver the vector composition, and the ability to safely maintain the position of the cannula of the invention.

[0285] In some embodiments of the invention, the volume of the composition injected to the subretinal space of the retina is more than about any one of 1 μΐ, 2 μΐ, 3 μΐ, 4 μΐ, 5 μΐ, 6 μΐ, 7 μΐ, 8 μΐ, 9 μΐ, 10 μΐ, 15 μΐ, 20 μΐ, 25 μΐ, 50 μΐ, 75 μΐ, 100 μΐ, 200 μΐ, 300 μΐ, 400 μΐ, 500 μΐ, 600 μΐ, 700 μΐ, 800 μΐ, 900 μΐ, or 1 mL, or any amount therebetween.

[0286] In some embodiments, the methods comprise administration to the eye (e.g., by subretinal and/or intravitreal administration) an effective amount of recombinant viral particles comprising a vector of the present disclosure. In some embodiments, the viral titer of the composition is at least about any of 5 x 10 ¹² , 6 x 10 ¹² , 7 x 10 ¹² , 8 x 10 ¹² , 9 x 10 ¹² , 10 x 10 ¹² , 11 x 10 ¹² , 15 x 10 ¹² , 20 x 10 ¹² , 25 x 10 ¹² , 30 x 10 ¹² , or 50 x 10 ¹² genome copies/mL. In

12 12 some embodiments, the viral titer of the composition is about any of 5 x 10 to 6 x 10 , 6 x 10 ¹² to 7 x 10 ¹² , 7 x 10 ¹² to 8 x 10 ¹² , 8 x 10 ¹² to 9 x 10 ¹² , 9 x 10 ¹² to 10 x 10 ¹² , 10 x 10 ¹² to 11 x 10 ¹² , 11 x 10 ¹² to 15 x 10 ¹² , 15 x 10 ¹² to 20 x 10 ¹² , 20 x 10 ¹² to 25 x 10 ¹² , 25 x 10 ¹² to 30 x 10 ¹² , 30 x 10 ¹² to 50 x 10 ¹² , or 50 x 10 ¹² to 100 x 10 ¹² genome copies/mL. In some

12 12 embodiments, the viral titer of the composition is about any of 5 x 10 to 10 x 10 , 10 x 10 ¹² to 25 x 10 ¹² , or 25 x 10 ¹² to 50 x 10 ¹² genome copies/mL. In some embodiments, the viral titer of the composition is at least about any of 5 x 10 ⁹ , 6 x 10 ⁹ , 7 x 10 ⁹ , 8 x 10 ⁹ , 9 x 10 ⁹ , 10 x 10 ⁹ , 11 x 10 ⁹ , 15 x 10 ⁹ , 20 x 10 ⁹ , 25 x 10 ⁹ , 30 x 10 ⁹ , or 50 x 10 ⁹ transducing units /mL. In some embodiments, the viral titer of the composition is about any of 5 x 10 ⁹ to 6 x 10 ⁹ , 6 x 10 ⁹ to 7 x 10 ⁹ , 7 x 10 ⁹ to 8 x 10 ⁹ , 8 x 10 ⁹ to 9 x 10 ⁹ , 9 x 10 ⁹ to 10 x 10 ⁹ , 10 x 10 ⁹ to 11 x 10 ⁹ , 11 x 10 ⁹ to 15 x 10 ⁹ , 15 x 10 ⁹ to 20 x 10 ⁹ , 20 x 10 ⁹ to 25 x 10 ⁹ , 25 x 10 ⁹ to 30 x 10 ⁹ , 30 x 10 ⁹ to 50 x 10 ⁹ or 50 x 10 ⁹ to 100 x 10 ⁹ transducing units /mL. In some

embodiments, the viral titer of the composition is about any of 5 x 10 ⁹ to 10 x 10 ⁹ , 10 x 10 ⁹ to 15 x 10 ⁹ , 15 x 10 ⁹ to 25 x 10 ⁹ , or 25 x 10 ⁹ to 50 x 10 ⁹ transducing units /mL. In some embodiments, the viral titer of the composition is at least any of about 5 x 10 ¹⁰ , 6 x 10 ¹⁰ , 7 x 10 ¹⁰ , 8 x 10 ¹⁰ , 9 x 10 ¹⁰ , 10 x 10 ¹⁰ , 11 x 10 ¹⁰ , 15 x 10 ¹⁰ , 20 x 10 ¹⁰ , 25 x 10 ¹⁰ , 30 x 10 ¹⁰ , 40 x 10 ¹⁰ , or 50 x 10 ¹⁰ infectious units/mL. In some embodiments, the viral titer of the

composition is at least any of about 5 x 10 ¹⁰ to 6 x 10 ¹⁰ , 6 x 10 ¹⁰ to 7 x 10 ¹⁰ , 7 x 10 ¹⁰ to 8 x 10 ¹⁰ , 8 x 10 ¹⁰ to 9 x 10 ¹⁰ , 9 x 10 ¹⁰ to 10 x 10 ¹⁰ , 10 x 10 ¹⁰ to 11 x 10 ¹⁰ , 11 x 10 ¹⁰ to 15 x 10 ¹⁰ , 15 x 10 ^1U to 20 x 10 , 20 x 10 ^1U to 25 x 10 , 25 x 10 ^1U to 30 x 10 , 30 x 10 ^1U to 40 x 10 , 40 x 10 ¹⁰ to 50 x 10 ¹⁰ , or 50 x 10 ¹⁰ to 100 x 10 ¹⁰ infectious units/mL. In some embodiments, the viral titer of the composition is at least any of about 5 x 10 ¹⁰ to 10 x 10 ¹⁰ , 10 x 10 ¹⁰ to 15 x 10 ¹⁰ , 15 x 10 ¹⁰ to 25 x 10 ¹⁰ , or 25 x 10 ¹⁰ to 50 x 10 ¹⁰ infectious units/mL.

[0287] In some embodiments, the methods comprise administration to the eye (e.g., by subretinal and/or intravitreal administration) of an individual (e.g., a human) an effective amount of recombinant viral particles comprising a vector of the present disclosure. In some embodiments, the dose of viral particles administered to the individual is at least about any of

8 13

1 x 10° to about 1 x 10 ^1J genome copies/kg of body weight. In some embodiments, the dose

8 13 of viral particles administered to the individual is about any of 1 x 10 to about 1 x 10 genome copies/kg of body weight.

[0288] One or multiple (e.g., 2, 3, or more) blebs can be created. Generally, the total volume of bleb or blebs created by the methods and systems of the invention cannot exceed the fluid volume of the eye, for example about 4 ml in a typical human subject. The total volume of each individual bleb can be at least about 0.3 ml, or at least about 0.5 ml in order to facilitate a retinal detachment of sufficient size to expose the cell types of the central retina and create a bleb of sufficient dependency for optimal manipulation. One of ordinary skill in the art will appreciate that in creating the bleb according to the methods and systems of the invention that the appropriate intraocular pressure must be maintained in order to avoid damage to the ocular structures. The size of each individual bleb may be, for example, about 0.5 to about 1.2 ml, about 0.8 to about 1.2 ml, about 0.9 to about 1.2 ml, about 0.9 to about 1.0 ml, about 1.0 to about 2.0 ml, about 1.0 to about 3.0 ml. Thus, in one example, to inject a total of 3 ml of vector composition suspension, 3 blebs of about 1 ml each can be established. The total volume of all blebs in combination may be, for example, about 0.5 to about 3.0 ml, about 0.8 to about 3.0 ml, about 0.9 to about 3.0 ml, about 1.0 to about 3.0 ml, about 0.5 to about 1.5 ml, about 0.5 to about 1.2 ml, about 0.9 to about 3.0 ml, about 0.9 to about 2.0 ml, about 0.9 to about 1.0 ml.

[0289] In order to safely and efficiently transduce areas of target retina (e.g., the central retina) outside the edge of the original location of the bleb, the bleb may be manipulated to reposition the bleb to the target area for transduction. Manipulation of the bleb can occur by the dependency of the bleb that is created by the volume of the bleb, repositioning of the eye containing the bleb, repositioning of the head of the human with an eye or eyes containing one or more blebs, and/or by means of a fluid-air exchange. This is particularly relevant to the central retina since this area typically resists detachment by subretinal injection. In some embodiments fluid-air exchange is utilized to reposition the bleb; fluid from the infusion cannula is temporarily replaced by air, e.g., from blowing air onto the surface of the retina. As the volume of the air displaces vitreous cavity fluid from the surface of the retina, the fluid in the vitreous cavity may flow out of a cannula. The temporary lack of pressure from the vitreous cavity fluid causes the bleb to move and gravitate to a dependent part of the eye. By positioning the eye globe appropriately, the bleb of subretinal vector composition is manipulated to involve adjacent areas (e.g., the macula and/or fovea). In some cases, the mass of the bleb is sufficient to cause it to gravitate, even without use of the fluid-air exchange. Movement of the bleb to the desired location may further be facilitated by altering the position of the subject' s head, so as to allow the bleb to gravitate to the desired location in the eye. Once the desired configuration of the bleb is achieved, fluid is returned to the vitreous cavity. The fluid is an appropriate fluid, e.g. , fresh saline. Generally, the subretinal vector composition may be left in situ without retinopexy to the retinotomy and without intraocular tamponade, and the retina will spontaneously reattach within about 48 hours.

[0290] By safely and effectively transducing ocular cells (e.g., RPE and/or photoreceptor cells of e.g., the macula and/or fovea) with a vector of the present disclosure, the methods of the invention may be used to treat an individual; e.g. , a human, having an ocular disorder associated with a deep intronic mutation, wherein the transduced cells produce the CRISPR- Cas system in an amount sufficient to treat the ocular disorder.

[0291] An effective amount of vector (in some embodiments in the form of viral particles) is administered, depending on the objectives of treatment. For example, where a low percentage of transduction can achieve the desired therapeutic effect, then the objective of treatment is generally to meet or exceed this level of transduction. In some instances, this level of transduction can be achieved by transduction of only about 1 to 5% of the target cells, in some embodiments at least about 20% of the cells of the desired tissue type, in some embodiments at least about 50%, in some embodiments at least about 80%, in some embodiments at least about 95%, in some embodiments at least about 99% of the cells of the desired tissue type. As a guide, the number of viral particles administered per injection is generally between about lxlO ⁶ and about lxlO ¹⁴ particles, between about lxlO ⁷ and lxlO ¹³ particles, between about lxlO ⁹ and lxlO ¹² particles or about lxlO ¹¹ particles. The vector composition may be administered by one or more subretinal injections, either during the same procedure or spaced apart by days, weeks, months, or years. In some embodiments, multiple vectors may be used to treat the human.

[0292] In some embodiments, the administration to the retina of an effective amount of a vector or nucleic acid of the present disclosure transduces photoreceptor cells at or near the site of administration. In some embodiments, more than about any of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 100% of photoreceptor cells are transduced. In some embodiments, about 5% to about 100%, about 10% to about 50%, about 10% to about 30%, about 25% to about 75%, about 25% to about 50%, or about 30% to about 50% of the photoreceptor cells are transduced. Methods to identify transduced photoreceptor cells are known in the art; for example, immunohistochemistry or the use of a marker such as enhanced green fluorescent protein can be used to detect transduction.

[0293] In some embodiments of the invention, the methods comprise administration to the subretina (e.g., the subretinal space) of a mammal an effective amount of a vector or nucleic acid of the present disclosure for treating an individual with an ocular disorder; e.g., a human with an ocular disorder associated with a deep intronic mutation. In some embodiments, the composition is injected to one or more locations in the subretina to allow expression of the nucleic acid in photoreceptor cells. In some embodiments, the composition is injected into any one of one, two, three, four, five, six, seven, eight, nine, ten or more than ten locations in the subretina.

[0294] In some embodiments the composition is administered to more than one location simultaneously or sequentially. In some embodiment, multiple injections are no more than one hour, two hours, three hours, four hours, five hours, six hours, nine hours, twelve hours or 24 hours apart. In some embodiment, multiple injections are one day, two days, three days, four days, five days, six days, seven days, ten days, 15 days, 20 days, 25 days, or 30 days apart. In some embodiment, multiple injections are one month, two months, three months, four months, five months, six months, eight months, ten months, or eleven month apart. In some embodiment, multiple injections are one year, two years, three years, four years, five years, six years, eight years, ten years, 15 years, 20 years, 25 years, 30 years, 35 years, 40 years, 45 years, 50 years, 55 years, or 60 years apart. Methods of Intravitreal injection

[0295] The general method for intravitreal injection may be illustrated by the following brief outline. This example is merely meant to illustrate certain features of the method, and is in no way meant to be limiting. Procedures for intravitreal injection are known in the art (see, e.g., Peyman, G.A., et al. (2009) Retina 29(7):875-912 and Fagan, X.J. and Al-Qureshi, S. (2013) Clin. Experiment. Ophthalmol. 41(5):500-7).

[0296] Briefly, a subject for intravitreal injection may be prepared for the procedure by pupillary dilation, sterilization of the eye, and administration of anesthetic. Any suitable mydriatic agent known in the art may be used for pupillary dilation. Adequate pupillary dilation may be confirmed before treatment. Sterilization may be achieved by applying a sterilizing eye treatment, e.g., an iodide-containing solution such as Povidone-Iodine

(BETADINE®). A similar solution may also be used to clean the eyelid, eyelashes, and any other nearby tissues {e.g., skin). Any suitable anesthetic may be used, such as lidocaine or proparacaine, at any suitable concentration. Anesthetic may be administered by any method known in the art, including without limitation topical drops, gels or jellies, and subconjuctival application of anesthetic.

[0297] Prior to injection, a sterilized eyelid speculum may be used to clear the eyelashes from the area. The site of the injection may be marked with a syringe. The site of the injection may be chosen based on the lens of the patient. For example, the injection site may be 3-3.5 mm from the limus in pseudophakic or aphakic patients, and 3.5-4 mm from the limbus in phakic patients. The patient may look in a direction opposite the injection site.

[0298] In some embodiments, the methods comprise administration to the eye {e.g., by subretinal and/or intravitreal administration) an effective amount of recombinant viral particles comprising a vector of the present disclosure. In some embodiments, the viral titer of the composition is at least about any of 5 x 10 ¹² , 6 x 10 ¹² , 7 x 10 ¹² , 8 x 10 ¹² , 9 x 10 ¹² , 10 x 10 ¹² , 11 x 10 ¹² , 15 x 10 ¹² , 20 x 10 ¹² , 25 x 10 ¹² , 30 x 10 ¹² , or 50 x 10 ¹² genome copies/mL. In some embodiments, the viral titer of the composition is about any of 5 x 10 12 to 6 x 1012 , 6 x 10 ¹² to 7 x 10 ¹² , 7 x 10 ¹² to 8 x 10 ¹² , 8 x 10 ¹² to 9 x 10 ¹² , 9 x 10 ¹² to 10 x 10 ¹² , 10 x 10 ¹² to 11 x 10 ¹² , 11 x 10 ¹² to 15 x 10 ¹² , 15 x 10 ¹² to 20 x 10 ¹² , 20 x 10 ¹² to 25 x 10 ¹² , 25 x 10 ¹² to 30 x 10 ¹² , 30 x 10 ¹² to 50 x 10 ¹² , or 50 x 10 ¹² to 100 x 10 ¹² genome copies/mL. In some embodiments, the viral titer of the composition is about any of 5 x 10 12 to 10 x 1012 , 10 x 10 ¹² to 25 x 10 ¹² , or 25 x 10 ¹² to 50 x 10 genome copies/mL. In some embodiments, the viral titer of the composition is at least about any of 5 x 10 ⁹ , 6 x 10 ⁹ , 7 x 10 ⁹ , 8 x 10 ⁹ , 9 x 10 ⁹ , 10 x 10 ⁹ , 11 x 10 ⁹ , 15 x 10 ⁹ , 20 x 10 ⁹ , 25 x 10 ⁹ , 30 x 10 ⁹ , or 50 x 10 ⁹ transducing units /mL. In some embodiments, the viral titer of the composition is about any of 5 x 10 ⁹ to 6 x 10 ⁹ , 6 x 10 ⁹ to 7 x 10 ⁹ , 7 x 10 ⁹ to 8 x 10 ⁹ , 8 x 10 ⁹ to 9 x 10 ⁹ , 9 x 10 ⁹ to 10 x 10 ⁹ , 10 x 10 ⁹ to 11 x 10 ⁹ , 11 x 10 ⁹ to 15 x 10 ⁹ , 15 x 10 ⁹ to 20 x 10 ⁹ , 20 x 10 ⁹ to 25 x 10 ⁹ , 25 x 10 ⁹ to 30 x 10 ⁹ , 30 x 10 ⁹ to 50 x 10 ⁹ or 50 x 10 ⁹ to 100 x 10 ⁹ transducing units /mL. In some

embodiments, the viral titer of the composition is about any of 5 x 10 ⁹ to 10 x 10 ⁹ , 10 x 10 ⁹ to 15 x 10 ⁹ , 15 x 10 ⁹ to 25 x 10 ⁹ , or 25 x 10 ⁹ to 50 x 10 ⁹ transducing units /mL. In some embodiments, the viral titer of the composition is at least any of about 5 x 10 ¹⁰ , 6 x 10 ¹⁰ , 7 x 10 ¹⁰ , 8 x 10 ¹⁰ , 9 x 10 ¹⁰ , 10 x 10 ¹⁰ , 11 x 10 ¹⁰ , 15 x 10 ¹⁰ , 20 x 10 ¹⁰ , 25 x 10 ¹⁰ , 30 x 10 ¹⁰ , 40 x 10 ¹⁰ , or 50 x 10 ¹⁰ infectious units/mL. In some embodiments, the viral titer of the

composition is at least any of about 5 x 10 ¹⁰ to 6 x 10 ¹⁰ , 6 x 10 ¹⁰ to 7 x 10 ¹⁰ , 7 x 10 ¹⁰ to 8 x 10 ¹⁰ , 8 x 10 ¹⁰ to 9 x 10 ¹⁰ , 9 x 10 ¹⁰ to 10 x 10 ¹⁰ , 10 x 10 ¹⁰ to 11 x 10 ¹⁰ , 11 x 10 ¹⁰ to 15 x 10 ¹⁰ , 15 x 10 ¹⁰ to 20 x 10 ¹⁰ , 20 x 10 ¹⁰ to 25 x 10 ¹⁰ , 25 x 10 ¹⁰ to 30 x 10 ¹⁰ , 30 x 10 ¹⁰ to 40 x 10 ¹⁰ , 40 x 10 ¹⁰ to 50 x 10 ¹⁰ , or 50 x 10 ¹⁰ to 100 x 10 ¹⁰ infectious units/mL. In some embodiments, the viral titer of the composition is at least any of about 5 x 10 ¹⁰ to 10 x 10 ¹⁰ , 10 x 10 ¹⁰ to 15 x 10 ¹⁰ , 15 x 10 ¹⁰ to 25 x 10 ¹⁰ , or 25 x 10 ¹⁰ to 50 x 10 ¹⁰ infectious units/mL.

[0299] In some embodiments, the methods comprise administration to the eye (e.g., by subretinal and/or intravitreal administration) of an individual (e.g., a human) an effective amount of recombinant viral particles comprising a vector of the present disclosure. In some embodiments, the dose of viral particles administered to the individual is at least about any of

8 13

1 x 10° to about 1 x 10 ^1J genome copies/kg of body weight. In some embodiments, the dose

8 13 of viral particles administered to the individual is about any of 1 x 10 to about 1 x 10 genome copies/kg of body weight.

[0300] During injection, the needle may be inserted perpendicular to the sclera and pointed to the center of the eye. The needle may be inserted such that the tip ends in the vitreous, rather than the subretinal space. Any suitable volume known in the art for injection may be used. After injection, the eye may be treated with a sterilizing agent such as an antiobiotic. The eye may also be rinsed to remove excess sterilizing agent. Structure of retina and means to determine effectiveness of nucleic acid delivery

[0301] The retina is known to contain multiple layers. Cell layers in the retina may include the inner limiting membrane, nerve fiber, ganglion cell, inner plexiform, inner nuclear, outer plexiform, outer nuclear, external limiting membrane, photoreceptor, and retinal pigment epithelium layers. The layer most proximal to the vitreous is the inner limiting membrane. This layer may contain Miiller cells, a class of glia. The nerve fiber layer may contain axons from ganglion cells that form the optic nerve. The ganglion cell layer may include ganglion cells and amacrine cells. The inner plexiform layer may contain synapses between dendrites of the ganglion and amacrine cells and axons of the bipolar cells. The inner nuclear layer may contain cell nuclei of amacrine, bipolar, and horizontal cells. The outer plexiform layer may contain synapses between horizontal cell dendrites and photoreceptor cell projections. The outer nuclear layer may contain photoreceptor cell bodies. The external or outer limiting membrane may include cell connections, such as adherens junctions and desmosomes, among Miiller cell apical processes and between these processes and photoreceptor cell inner segments. The photoreceptor layer, also known as the layer of rod and cones and Jacob's membrane, may contain photoreceptor cells include rods and cones. The retinal layer most distal to the vitreous is the retinal pigment epithelium (RPE), which may include a layer of hexagonal epithelial cells containing pigment granules.

[0302] The retina is also known to contain many different cell types. Retinal neurons may include photoreceptor cells, bipolar cells, ganglion cells, amacrine cells, and horizontal cells. Photoreceptor cells are sensitive to light. They may sense light and respond by transmitting signals to the optic nerve through the bipolar cells and the ganglion cells. Photoreceptor cells may include rod cells, which generally sense light in low-light conditions, and cone cells, which generally sense color and brighter light perception. Bipolar cells may receive inputs from photoreceptor cells and synapse onto amacrine or ganglion cells. Ganglion cells may receive information from amacrine cells or horizontal cells, and their axons form the optic nerve. Horizontal cells may integrate inputs from multiple photoreceptors and aid in adjustment to light levels. Amacrine cells are interneurons that help regulate bipolar cells and provide inputs to ganglion cells. Glial cells of the retina may include Miiller cells, astroglia, and microglia.

[0303] The effectiveness of nucleic acid delivery by subretinal or intravitreal injection can be monitored by several criteria as described herein. In some embodiments, the effectiveness is assayed by detecting the deletion of the deep intronic mutation and/or flanking sequence in a sample including one or more cells to which the nucleic acid(s) were delivered. Deletions may be detected by any means known in the art, including without limiting Southern blotting, PCR, qPCR, DNA sequencing (e.g., Sanger sequencing and next-generation sequencing), in situ hybridization, DNA microarray, and a Surveyor nuclease assay (see, e.g., Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308). Exemplary methods are illustrated in the Examples below.

[0304] In some embodiments, the effectiveness is assayed functionally. For example, after treatment in a subject using methods of the present invention, the subject may be assessed for e.g., an improvement and/or stabilization and/or delay in the progression of one or more signs or symptoms of the disease state by one or more clinical parameters. Examples of such tests are known in the art, and include objective as well as subjective (e.g., subject reported) measures. For example, to measure the effectiveness of a treatment on a subject's visual function, one or more of the following may be evaluated: the subject' s subjective quality of vision or improved central vision function (e.g., an improvement in the subject' s ability to read fluently and recognize faces), the subject's visual mobility (e.g., a decrease in time needed to navigate a maze), visual acuity (e.g., an improvement in the subject's LogMAR score), microperimetry (e.g., an improvement in the subject' s dB score), dark-adapted perimetry (e.g., an improvement in the subject's dB score), fine matrix mapping (e.g., an improvement in the subject' s dB score), Goldmann perimetry (e.g., a reduced size of scotomatous area (i.e. areas of blindness) and improvement of the ability to resolve smaller targets), flicker sensitivities (e.g., an improvement in Hertz), autofluorescence, and electrophysiology measurements (e.g., improvement in ERG). In some embodiments, the visual function is measured by the subject' s visual mobility. In some embodiments, the visual function is measured by the subject' s visual acuity. In some embodiments, the visual function is measured by microperimetry. In some embodiments, the visual function is measured by dark-adapted perimetry. In some embodiments, the visual function is measured by ERG. In some embodiments, the visual function is measured by the subject' s subjective quality of vision.

[0305] In the case of diseases resulting in progressive degenerative visual function, treating the subject at an early age may not only result in a slowing or halting of the progression of the disease, it may also ameliorate or prevent visual function loss due to acquired amblyopia.

-I l l- Amblyopia may be of two types. In studies in nonhuman primates and kittens that are kept in total darkness from birth until even a few months of age, the animals even when subsequently exposed to light are functionally irreversibly blind despite having functional signals sent by the retina. This blindness occurs because the neural connections and "education" of the cortex is developmentally is arrested from birth due to stimulus arrest. It is unknown if this function could ever be restored. In the case of diseases of retinal degeneration, normal visual cortex circuitry was initially "learned" or developmentally appropriate until the point at which the degeneration created significant dysfunction. The loss of visual stimulus in terms of signaling in the dysfunctional eye creates "acquired" or "learned" dysfunction ("acquired amblyopia"), resulting in the brain's inability to interpret signals, or to "use" that eye. It is unknown in these cases of "acquired amblyopia" whether with improved signaling from the retina as a result of gene therapy of the amblyopic eye could ever result in a gain of more normal function in addition to a slowing of the progression or a stabilization of the disease state. In some embodiments, the human treated is less than 30 years of age. In some embodiments, the human treated is less than 20 years of age. In some embodiments, the human treated is less than 18 years of age. In some embodiments, the human treated is less than 15 years of age. In some embodiments, the human treated is less than 14 years of age. In some embodiments, the human treated is less than 13 years of age. In some embodiments, the human treated is less than 12 years of age. In some embodiments, the human treated is less than 10 years of age. In some embodiments, the human treated is less than 8 years of age. In some embodiments, the human treated is less than 6 years of age.

[0306] In some ocular disorders, there is a "nurse cell" phenomena, in which improving the function of one type of cell improves the function of another. For example, transduction of the RPE of the central retina by a nucleic acid of the invention may then improve the function of the rods, and in turn, improved rod function results in improved cone function.

Accordingly, treatment of one type of cell may result in improved function in another.

[0307] The selection of a particular vector and composition depend on a number of different factors, including, but not limited to, the individual human's medical history and features of the condition and the individual being treated. The assessment of such features and the design of an appropriate therapeutic regimen is ultimately the responsibility of the prescribing physician. [0308] In some embodiments, the human to be treated has a genetic ocular disorder (e.g., associated with a deep intronic mutation), but has not yet manifested clinical signs or symptoms. In some embodiments, the human to be treated has an ocular disorder (e.g., associated with a deep intronic mutation). In some embodiments, the human to be treated has manifested one or more signs or symptoms of an ocular disorder (e.g., associated with a deep intronic mutation). In some embodiments, a deep intronic mutation has been identified in the human to be treated.

[0309] Compositions of the invention can be used either alone or in combination with one or more additional therapeutic agents for treating ocular disorders. The interval between sequential administration can be in terms of at least (or, alternatively, less than) minutes, hours, or days.

[0310] In some embodiments, one or more additional therapeutic agents may be

administered to the subretina or vitreous (e.g., through intravitreal administration). Non- limiting examples of the additional therapeutic agent include polypeptide neurotrophic factors (e.g., GDNF, CNTF, BDNF, FGF2, PEDF, EPO), polypeptide anti-angiogenic factors (e.g., sFlt, angiostatin, endostatin), anti-angiogenic nucleic acids (e.g. , siRNA, miRNA, ribozyme), for example anti-angiogenic nucleic acids against VEGF, anti-angiogenic morpholinos, for example anti-angiogenic morpholinos against VEGF, anti-angiogenic antibodies and/or antibody fragments (e.g., Fab fragments), for example anti-angiogenic antibodies and/or antibody fragments against VEGF.

VII. Kits

[0311] The compositions, nucleic acids, and viral particles as described herein may be contained within a kit designed for use in one of the methods of the invention as described herein.

[0312] The compositions, nucleic acids, and viral particles of the invention may further be packaged into kits, wherein the kits may further comprise instructions for use. In some embodiments, the instructions for use include instructions according to one of the methods described herein.

[0313] In some embodiments, the kits further contain buffers and/or pharmaceutically acceptable excipients. As is well known in the art, pharmaceutically acceptable excipients are relatively inert substances that facilitate administration of a pharmacologically effective substance and can be supplied as liquid solutions or suspensions, as emulsions, or as solid forms suitable for dissolution or suspension in liquid prior to use. For example, an excipient can give form or consistency, or act as a diluent. Suitable excipients include but are not limited to stabilizing agents, wetting and emulsifying agents, salts for varying osmolality, encapsulating agents, pH buffering substances, and buffers. Such excipients include any pharmaceutical agent suitable for direct delivery to the eye which may be administered without undue toxicity. Pharmaceutically acceptable excipients include, but are not limited to, sorbitol, any of the various TWEEN compounds, and liquids such as water, saline, glycerol and ethanol. Pharmaceutically acceptable salts can be included therein, for example, mineral acid salts such as hydrochlorides, hydrobromides, phosphates, sulfates, and the like; and the salts of organic acids such as acetates, propionates, malonates, benzoates, and the like. A thorough discussion of pharmaceutically acceptable excipients is available in

REMINGTON'S PHARMACEUTICAL SCIENCES (Mack Pub. Co., N.J. 1991).

[0314] In some embodiments, pharmaceutically acceptable excipients may include pharmaceutically acceptable carriers. Such pharmaceutically acceptable carriers can be sterile liquids, such as water and oil, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, and the like. Saline solutions and aqueous dextrose, polyethylene glycol (PEG) and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. Additional ingredients may also be used, for example preservatives, buffers, tonicity agents, antioxidants and stabilizers, nonionic wetting or clarifying agents, viscosity-increasing agents, and the like. The kits described herein can be packaged in single unit dosages or in multidosage forms. The contents of the kits are generally formulated as sterile and substantially isotonic solution.

EXAMPLES

[0315] The invention will be more fully understood by reference to the following examples. They should not, however, be construed as limiting the scope of the invention. It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. Example 1: Generating an In Vitro Model of Leber Congenital Amaurosis Using

Crispr-Cas9 Technology

Methods

Plasmids

[0316] The pSpCas9 plasmid that expresses SpCas9 was ordered from Sigma (Catalog number: CAS9P-1EA). The Bbsl restriction site in the BGH polyA was removed using the QuikChange Lightning Site-Directed Mutagenesis Kit (Stratagene) and a pair of mutagenesis primers (SEQ ID NOS: 28-29) following the manufacturer's protocol. A U6 promoter- BbsLBbsI-sgRNA scaffold-U6 terminator cassette (SEQ ID NO: 30) was synthesized by GeneArt (Life Technologies) and inserted into the Pcil and Nrul restriction sites of the pSpCas9-BbsI null plasmid to generate a pSpCas9(BB) plasmid. The sgRNA oligos (SEQ ID NOS: 1-2) were then subcloned into the two Bbsl restriction sites of the pSpCas9(BB) plasmid following the protocol described previously (Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308).

Nucleofection

[0317] 2.5 micrograms of the pSpCas9(BB)-U6-sgRNA plasmid DNA and 5 microliters of the ssODN (10 micromolar) (SEQ ID NO: 3) were co-transfected into lxl0 ⁶ HEK 293FT cells using the Amaxa SF cell line 4D-Nucleofector X kit L (Lonza) and the program CM- 130 in a 4D-Nucleofector System (Lonza), following the manufacturer's protocol.

Screening

[0318] To identify clones bearing the c.2991+1655A>G mutation of CEP290, cells were dissociated into single cells at 48 hr post-co-transfection and serially diluted to a final concentration of 0.5 cells per 100 microliters to reduce the likelihood of having multiple cells per well. 100 microliters of diluted cells were plated into each well of nine 96-well plates. The cells were expanded in a 5% C02, 37oC incubator for 2 weeks.

[0319] 235 single cell clones were identified and subjected to screening for the

c.2991+1655A>G mutation of CEP290. Genomic DNA was extracted using the QuickExtract DNA extraction solution (Epicentre) and amplified with GoTaq Hot Start Green Master Mix (Promega) and PCR primers flanking the intronic mutation (SEQ ID NOS: 4-5). Amplification of the PCR products was achieved with the following cycling parameters: 1 cycle at 95°C for 2 min; 35 cycles of 95°C for 30 sec, 60°C for 30 sec, and 72°C for 3 min; 1 cycle at 72°C for 15 min. The PCR products were subjected to SnaBI digestion and Sanger sequencing with a sequencing primer (SEQ ID NO: 6).

RT-qPCR

[0320] mRNAs were extracted from WT, Het, and MT cells using the RNeasy Plus Mini Kit (Qiagen) according to manufacturer's protocol. 1 microgram of total RNA was used to synthesize cDNA using the iScript cDNA synthesis kit (Bio-Rad) following manufacturer's protocol. cDNAs were subjected to real-time PCR amplification in a buffer containing Fast Plus EvaGreen qPCR Master Mix with low ROX (Biotium) and primers that specifically detect wild-type CEP290 mRNA (SEQ ID NOS: 7-8) and mutant CEP290 mRNA (SEQ ID NOS: 9-10), respectively, on an ABI Prism 7500 Real Time PCR System (Applied

Biosystems). The following conditions were used: 1 cycle at 50°C for 2 min; 1 cycle at 95°C for 10 min; 40 cycles of 95°C for 15 sec and 60°C for 60 sec. The specificity of amplification products was determined from melting curve analysis performed at the end of each run using a cycle at 95 °C for 15 sec, 60 °C for 60 sec, 95 °C for 15 sec, and 60 °C for 15 sec. Data were analyzed using the SDS 2.3 software (Applied Biosystems). CEP290 expression levels were normalized to the expression levels of PPIA mRNA (for primer sequences please see SEQ ID NOS: 31-32).

Western blot analysis

[0321] Cells were lysed in RIPA lysis buffer (Cell Signaling Technology) supplemented with 1 millimole/liter of phenylmethylsulfonyl fluoride (PMSF; Cell Signaling Technology) and IX protease inhibitor cocktail (Cell Signaling Technology) on ice. The cells were then scraped, collected in eppendorf tubes and the lysates were clarified by centrifugation at 13,000 rpm for 6 min at 4°C. The samples were prepared by adding the NuPage 4X LDS sample buffer and the NuPage 10X reducing agent (both from Life Technologies), heating at 70°C for 10 min and centrifuging at 13,000 rpm for 1 min. Protein samples were loaded on NuPAGE 3-8% Tris-Acetate gel along with HiMark pre-stainied protein standard (both from Life Technologies). The samples were resolved via gel electrophoresis at 180 volts for 1 hour. Running buffer used was Tris-Acetate SDS runner buffer (Life Technologies). For the transfer, polyvinylidine fluoride (PVDF) membranes were briefly treated in methanol and rinsed with water in order to make it hydrophilic. The transfer sandwich was prepared by sandwiching the PVDF membrane and the gel between filter papers and sponges in XCell II Blot Module (Life Technologies). Transfer buffer used was NuPage 20X transfer buffer (Life Technologies) with 20% methanol. The transfer was carried out at 30 volts for 2 hours in XCell SureLock Mini-Cell (Life Technologies). After the transfer, the PVDF membranes were blocked in Pierce TBST buffer (Tris-buffered saline with Tween 20 detergent; Thermo Fisher Scientific) containing 1% nonfat dry milk, shaking at room temperature for 1 hour. The blots were then incubated in the primary antibody solution made in the block solution, rocking for overnight at 4°C. The primary antibodies used are a rabbit polyclonal anti- CEP290 antibody (a kind gift from Professor Hemant Khanna at University of Massachusetts at Worcester), a mouse monoclonal anti-Cas9 antibody (clone 7A9; Millipore), a HRP conjugated-rabbit monoclonal anti-P-Actin antibody (clone 13E5; Cell Signaling

Technology). Unbound primary antibodies were washed 3 times for 10 min each with TBST. Secondary antibodies (Alexa Fluor 647 conjugated anti-rabbit or anti-mouse IgG; Cell Signaling Technology) in block solution were then added to the membranes and kept on a shaker for 1 hour at room temperature. The membranes were washed 3 times for 10 min each with TBST to reduce the non-specific background. The membranes were developed for 4 min using Pierce enhanced chemiluminescence (ECL) western blotting substrate (Thermo Fisher Scientific). The protein bands in the blots were finally visualized by exposing the film for various time intervals in a Kodak X-OMAT 2000 processor. To reprobe a blot for anti-β- Actin antibody, the membranes were first stripped by incubating at 37°C for 30 min in Restore western blot stripping buffer (Thermo Fisher Scientific) and then reprobed with the anti-P-Actin antibody. The blotting data shown in this work are representative of at least three independent experiments.

Results

[0322] First, the CRISPR-Cas9 genome editing technology was used to generate a cellular model carrying the intronic splice mutation c.2991+1655 A>G in CEP290. This cellular model is a valuable tool for evaluating therapeutics for treating LCA patients that harbor the c.2991+1655 A>G mutation in CEP290.

[0323] Genome editing with the bacterial type II CRISPR-Cas9 system is initiated with the introduction of a double- stranded break (DSB) at a targeted genomic locus defined by sgRNA target sequence and protospacer adjacent motif (PAM), and followed by the repair of the DSB through either homology-directed repair (HDR) or non-homologous end-joining (NHEJ) (Jinek, M. et al. (2012) Science 337:816-821; Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308). In the presence of a HDR template, the CRISPR-Cas9 system can be used to generate precise and defined modifications at a targeted locus through the HDR process.

[0324] To obtain targeted genomic DNA replacement, a plasmid that expresses both sgRNA and S. pyogenes Cas9 (SpCas9) along with a linear HDR template was introduced into 293FT cells via nucleofection. The HDR template is a single- stranded DNA

oligonucleotide (ssODN; SEQ ID NO: 3) that contains homology arms of 75 bp flanking the c.2991+1655A>G mutation along with mutated PAM (c.2991+1666C>G). The mutated PAM would avoid the donor ssODN being degraded by Cas9 in cells, and in the meantime introduce a unique SnaBl restriction site to the intron 26 of CEP290.

[0325] To obtain cells that carry the c.2991+1655A>G mutation of CEP290, 235 single cell clones were isolated and screened from sgRNA/SpCas9 and ssODN co-transfected cells. Genomic DNA was extracted and amplified with PCR primers flanking the intronic mutation (SEQ ID NOS: 4-5). The PCR products were subjected to SnaBl digestion and Sanger sequencing with a sequencing primer (SEQ ID NO: 6).

[0326] Among the 235 single cell clones, one clone contained the c.2991+1655A>G and c.2991+1666C>G mutations on both CEP290 alleles (hereafter referred to as the "mutant cells" or the "MT cells"). Another clone contained the two mutations on one CEP290 allele and the endogenous wild-type CEP290 DNA on the other allele (hereafter referred to as the "heterozygous cells" or the "Het cells"). Cells that contained two alleles of endogenous wild- type CEP290 are hereafter referred to as the "wild-type cells" or the "WT cells."

[0327] Expression levels of wild-type and mutant CEP290 mRNAs in wild-type, heterozygous, and mutant cells were measured by reverse transcription quantitative PCR (RT-qPCR) using primers that specifically detect wild-type CEP290 mRNA (SEQ ID NOS: 7-8) and mutant CEP290 mRNA (SEQ ID NOS: 9-10), respectively. Results were normalized to the expression levels of PPIA mRNA (SEQ ID NOS: 31-32).

[0328] Compared to wild-type cells, the mRNA levels of wild-type CEP290 were reduced by 27% and 48% in heterozygous and mutant cells, respectively (FIG. 3A). As expected, wild-type cells did not express mutant CEP290 mRNA, whereas its levels were 24% higher in mutant cells than in heterozygous cells (FIG. 3B). Compared to heterozygous cells, mutant cells expressed significantly lower levels of wild-type CEP290 mRNA and significantly higher levels of mutant CEP290 mRNA. Therefore, this cellular model recapitulates the phenotype in LCA patients carrying the c.2991+1655 A>G mutation, as these patients express a -50% reduced level of wild-type CEP290 mRNA (den Hollander, A.I. et al. (2006) Am. J. Hum. Genet. 79:556-561).

[0329] Protein levels of CEP290 in wild-type, heterozygous, and mutant cells were examined by Western blot analysis. Compared to wild-type cells, the CEP290 protein levels in heterozygous and mutant cells were greatly reduced (FIG. 3C). Mutant cells expressed lower levels of CEP290 protein compared to heterozygous cells (FIG. 3C). Therefore, the immunoblot data are consistent with the RT-qPCR data.

Example 2: Targeted Deletion of the c.2991+1655 A>G Mutation

Methods

Plasmids

[0330] An all-in-one expression vector was constructed with the Golden Gate cloning method as previously described (Sakuma, T. et al. (2014) Sci. Rep. 4:5400). Briefly, a DNA fragment that contains U6 promoter-BbsLBbsI-sgRNA scaffold-U6 terminator-CMV promoter (SEQ ID NO: 33) was synthesized by GeneArt (Life Technologies) and inserted into the Pcil and Nhel restriction sites of the pSpCas9-BbsI null plasmid described above to generate a pSpCas9(BBU) plasmid that is used to subclone the upstream sgRNA guide sequences. To construct a pSpCas9(BBD) plasmid that is used to subclone the downstream sgRNA guide sequences, a PCR reaction was performed using the Phusion High-Fidelity DNA Polymerase (New England Bio Labs Inc) with the pSpCas9(BB) plasmid DNA as the DNA template and a pair of PCR primers (SEQ ID NOS: 34-35). The cycling parameters were: 1 cycle at 98°C for 1 min; 35 cycles of 98°C for 20 sec and 72°C for 30 sec; 1 cycle at 72°C for 5 min. The PCR product was inserted into the Pcil and Kpnl sites of the

pSpCas9(BBU) plasmid. In this pSpCas9(BBD) plasmid, two Bsal sites flank the U6 promoter-driven sgRNA. The Ul sgRNA oligos (SEQ ID NOS: 11-12) were annealed and then subcloned into the two Bbsl restriction sites of the pSpCas9(BBU) plasmid, and the Dl, D2, and D3 sgRNA oligos (SEQ ID NOS: 13-18) were annealed and then subcloned into the two Bbsl restriction sites of the pSpCas9(BBD) plasmid following the protocol described previously (Ran, F.A. et al. (2013) Nat. Protoc. 8:2281-2308). The resultant D1-D3 sgRNAs along with the U6 promoter were further cut out from the pSpCas9(BBD) plasmids using the restriction enzyme Bsal and then subcloned into the two Bsal sites in the pSpCas9(BBU)-Ul sgRNA plasmid. The resultant pSpCas9(BBUD) plasmids express two U6 promoter-driven sgRNAs and one CMV promoter-driven SpCas9. The oligos for two control sgRNAs (SEQ ID NOS: 36-39) were subcloned into the Bbsl restriction sites of the same all-in-one expression vector using the method described above as the control plasmid.

Transfection and PCR analysis

[0331] The paired sgRNAs-SpCas9 plasmids were transfected into wild-type,

heterozygous, and mutant cells using the Lipofectamine 3000 Transfection Reagent (Life Technologies) following manufacturer's protocol.

[0332] 48 hr post-transfection, genomic DNA was extracted from cells using the

QuickEx tract DNA extraction solution (Epicentre) and amplified with GoTaq Hot Start Green Master Mix (Promega) and PCR primers flanking the intronic mutation (SEQ ID NOS: 4-5). Amplification of the PCR products was achieved with the following cycling parameters: 1 cycle at 95°C for 2 min; 35 cycles of 95°C for 30 sec, 60°C for 30 sec, and 72°C for 3 min; 1 cycle at 72°C for 15 min. PCR products were then subjected to agarose gel electrophoresis.

Next-generation sequencing (NGS)

[0333] PCR products acquired above were sent to ACGT (Wheeling, IL) for NGS sequencing. The sample DNA were fragmented to an average 350 bp target fragment size by ultrasonication, and used for constructing a sequencing library using the Illumina TruSeq DNA PCR-free sample preparation kit. The library was quantified via Qubit and 2100 Bioanalyzer, and loaded onto an Illumina platform to generate PE150 reads. Approximately 150K reads (+ 20%) per sample were generated. Raw Illumina were de-multiplexed and converted into .fastq format, and low quality (Q<20) Dand short reads (N<50) were filtered out. The filtered reads were aligned to the reference sequences (wild-type DNA and truncated DNA) using Bowtie2. For quantification, the number of reads aligned to a 40 bp sequence flanking the Ul sgRNA cleavage site (20 bp before and 20 bp after the cleavage site) that are unique to either the wild-type DNA or the truncated DNA were used to calculate the percentage of wild-type and truncated DNA in each sample. Results

[0334] Next, the model described above was used to test the approach for generating a targeted deletion of the c.2991+1655 A>G mutation.

[0335] One upstream sgRNA (Ul, SEQ ID NO: 19) that targets a locus within the cryptic exon was expressed together with each of three downstream sgRNAs (Dl, D2, D3; SEQ ID NOS: 20-22) in the same vector as SpCas9. The pairs of upstream and downstream sgRNAs all flank the c.2991+1655A>G mutation and are predicted to generate genomic deletions of 283 bp, 187 bp, and 231 bp, respectively, as previous studies have demonstrated that repair of paired sgRNAs-induced genomic deletion is largely accomplished by precise end joining (Brandl, C. et al. (2014) FEBS Open Bio. 5:26-35; Zheng, Q. et al. (2014) Biotechniques 57: 115-124). Two control sgRNAs were subcloned into the same plasmid as control.

[0336] The paired sgRNAs-SpCas9 plasmids were transfected into wild-type,

heterozygous, and mutant cells as described above, followed by PCR analysis using primers flanking the deletion regions (SEQ ID NOS: 4-5). Wild-type and truncated genomic fragments were resolved by gel electrophoresis. For all the three tested upstream/downstream sgRNA pairs, PCR products were detected that indicate the presence of expected genomic deletions, which were absent in the control sgRNAs-transfected cells (FIG. 4A). These results demonstrate that the paired sgRNAs and SpCas9 are capable of removing the c.2991+1655A>G mutation. Next-generation sequencing (NGS) analysis of the 4 PCR samples prepared from the mutant cells further revealed that 60.7%, 65.9%, and 72.4% NGS reads were aligned to the truncated DNA in U1D1-, U1D2-, and U1D3 -transfected cells, respectively. Therefore, all the three sgRNA pairs and SpCas9 are highly efficient in removing the c.2991+1655A>G mutation.

[0337] To confirm that the paired sgRNAs were able to rescue wild-type CEP290 expression levels in heterozygous and mutant cells, wild-type, heterozygous and mutant cells were transfected with the plasmids that express paired sgRNAs and SpCas9, followed by RT- qPCR analysis for CEP290 mRNA as described above. Results were normalized to the expression levels of PPIA mRNA.

[0338] Compared to control sgRNAs, sgRNA pairs, especially the U1D3 pair, markedly rescued wild-type CEP290 mRNA levels (FIG. 5A) and reduced mutant CEP290 mRNA levels (FIG. 5B) in heterozygous and mutant cells. Importantly, none of the three sgRNA pairs significantly changed wild-type CEP290 mRNA levels (FIG. 5A), suggesting that the targeted genomic deletions did not interfere with normal splicing of CEP290 transcripts. The U1D3 sgRNA pair markedly rescued wild-type CEP290 mRNA levels in heterozygous and mutant cells to levels comparable to that in wild-type cells (FIG. 5A). The U1D2 sgRNA pair also significantly increased wild-type CEP290 mRNA levels in heterozygous cells (FIG. 5A). All three sgRNA pairs significantly reduced mutant CEP290 mRNA levels in heterozygous cells (FIG. 5B). The pairs of U1D2 and U1D3 sgRNAs significantly reduced mutant CEP290 mRNA levels in MT cells (FIG. 5B).

[0339] To confirm that the paired sgRNAs were able to rescue wild-type CEP290 protein expression in mutant cells, mutant cells were transfected with paired sgRNAs and SpCas9 and then subjected to Western blot analysis as described above. Compared to control sgRNAs, all three sgRNA pairs rescued CEP290 protein expression (FIG. 5C).

[0340] Taken together, these data demonstrate that the upstream/downstream sgRNA pairs, especially the U1D3 pair, are highly efficient in preventing the splicing of the mutant cryptic exon and restoring wild-type CEP290 expression. These results demonstrate that a pair of guide RNAs coupled with Cas9 can permanently delete the intron region flanking the c.2991+1655 A>G mutation of CEP290 for preventing the splicing of the cryptic exon inserted into the CEP290 mRNA.

Example 3: Developing a Self-limiting Crispr-Cas9 System to Limit the SpCas9

Persistence Time

Methods

Plasmids

[0341] An AAV packaging plasmid pAAV-minCMV-SpCas9-NLS-SV40 pA was constructed for the self-limiting Crispr-Cas9 system. Briefly, a DNA fragment that contains a minimal promoter fragment derived from the CMV promoter (minCMV promoter) (SEQ ID NO: 56) was synthesized by GeneArt (Life Technologies) and inserted into the Mlul and Apol restriction sites of the Sigma pSpCas9 plasmid described above to generate a pminCMV-SpCas9-NLS-BGH pA plasmid. Next, a DNA fragment that contains SV40 early poly(A) signal (SV40 pA) (SEQ ID NO: 57) was synthesized by GeneArt (Life

Technologies) and inserted into the Xhol and Bbsl restriction sites of the above plasmid to generate a pminCMV-SpCas9-NLS-SV40 pA plasmid. Finally, the minCMV-SpCas9-NLS- SV40 pA fragment was subcloned into an AAV packaging plasmid to generate a pAAV- minCMV-SpCas9-NLS-SV40 pA.

[0342] To construct self-limiting pSpCas9 plasmid, the recognition sequences for the SpCas9 nuclease (Ul and D3 sgRNA target sequences plus corresponding PAM motifs; SEQ ID NOS: 58-59) were subcloned into the insertion site 1 (between minCMV promoter and SpCas9) and/or the insertion site 2 (between SpCas9-nuclear localization signal (NLS) and SV40 poly(A) signal).

[0343] The second AAV packaging plasmid for the self-limiting Crispr-Cas9 system is pAAV-U6-Ul sgRNA-U6-D3 sgRNA-BGH pA. To construct this plasmid, the U6-U1 sgRNA-U6-D3 sgRNA fragment was cut out from the pSpCas9(BBUD)-UlD3 plasmid using the restriction enzymes Pcil and Kpnl and then subcloned into the EcoRV and Kpnl sites of the AAV packaging plasmid to generate a pAAV-U6-Ul sgRNA-U6-D3 sgRNA plasmid. For AAV titering purpose, a BGH pA fragment (SEQ ID NO: 60) was cloned into the Spel and Hindlll sites of this plasmid.

Results

[0344] CRISPR-Cas9 is a powerful tool for genome editing, but it is unclear how expression of the bacterial protein Cas9 will be tolerated in patients. CRISPR-Cas9 works quickly (hours to days) and its prolonged presence in cells is not necessary. Unwanted immune responses and potential safety problems can be caused by prolonged expression of exogenous protein. For example, expression of exogenous marker protein green fluorescent protein (GFP) can elicit substantial unwanted immunological responses (Stripecke R et al. (1999) Gene Ther. 6: 1305-1312). In addition, a recent report suggested that there is induction of humoral immunity against Cas9 and the potential presence of a Cas9-specific cellular immune response after in vivo delivery of CRISPR-Cas9 (Wang, D. et al. (2015) Hum. Gene Ther. 26:432-442). Therefore, a "hit and go" approach in which exposure to Cas9 protein is restricted may be beneficial to in vivo delivery of CRISPR-Cas9. Such "hit and go" approach may also reduce the off-target effects since this will reduce the interaction time between Cas9 and unintended targets.

[0345] To this end, we developed a self-limiting Crispr-Cas9 system to limit the SpCas9 persistence time by incorporating recognition site(s) for the sgRNA(s) into the SpCas9 vector itself such that the vector will be cut and destroyed shortly after SpCas9 expression begins. The self-limiting Crispr-Cas9 system comprises two vectors: a pAAV-U6-Ul sgRNA-U6-D3 sgRNA vector that expresses the sgRNA pair Ul and D3, and a pAAV-minCMV-SpCas9- NLS-SV40 pA vector that expresses a minCMV promoter-driven SpCas9. The recognition sequences for the Ul and/or D3 sgRNA (target sequences plus corresponding PAM motifs) are incorporated into either one or two of the two insertion sites in the second vector. The insertion site 1 is located between the minCMV promoter and the SpCas9 coding sequence, and the insertion site 2 is located between the nuclear localization signal (NLS) and the SV40 poly(A) signal (FIG. 6A). Therefore, in this self-limiting Crispr-Cas9 system, Ul and D3 sgRNAs will guide SpCas9 protein for both targeted genomic deletion and cleavage of the self-limiting SpCas9 vector itself, which will prevent the vector from making excessive SpCas9 protein.

[0346] To test the self-limiting Crispr-Cas9 system in vitro, mutant cells were transfected with the two vectors described above, followed by Western blot analysis (FIG. 6B), genomic DNA PCR (FIG. 6C), and RT-qPCR analysis for CEP290 mRNA (FIGS. 6D&6E) as described above.

[0347] When single sgRNA recognition sequence (U1T or D3T; SEQ ID NOS: 58-59) was inserted into the self-limiting SpCas9 vector, the SpCas9 protein levels were greatly reduced compared to the control SpCas9 vector that does not contain the sgRNA recognition sequence (FIG. 6B). When two U1T, two D3T, or combined D3T and U1T were inserted into the self- limiting SpCas9 vector, the SpCas9 protein level was almost abolished (FIG. 6B). Therefore, the self-limiting Crispr-Cas9 system can effectively restrict SpCas9 expression.

[0348] To confirm that the self-limiting Crispr-Cas9 system is still able to induce targeted gemomic deletion and remove the LCA10 c.2991+1655A>G mutation, we performed genomic DNA PCR analysis in the dual vectors-transfected mutant cells (FIG. 6C). The PCR band corresponding to the truncated DNA was present in both the control SpCas9 vector- trasnfected cells and the self-limiting SpCas9 vectors -tranfected cells, suggesting that the self-limiting Crispr-Cas9 system is still able to remove the LCA10 intronic mutation despite the short persistence time of SpCas9. It is noteworthy that the genomic deletion observed in FIG. 6C was not as robust as the deletion seen in FIG. 4A. This could be due to different experimental conditions in these two studies. First, we used an all-in-one vector in FIG. 4A, and used dual vectors in FIG. 6C. Secondly, the SpCas9 expression was driven by a CMV promoter in FIG. 4A and driven by a minCMV promoter in FIG. 6C.

[0349] Next, we examined wild-type and mutant CEP290 mRNA levels in mutant cells transfected with the dual vectors. Compared to U1D3 sgRNAs alone (control), the control SpCas9 vector significantly rescued wild-type CEP290 mRNA levels in the mutant cells (FIG. 6D). Similarly, the SpCas9 vector that contains the D3 sgRNA recognition sequence at either insertion site significantly increased wild-type CEP290 mRNA levels (FIG. 6D). Other self-limiting SpCas9 vectors also increased wild-type CEP290 mRNA levels, although the differences were not statistically significant when compared to the control (FIG. 6D). In addition, all the self-limiting SpCas9 vectors and the control SpCas9 vector significantly reduced mutant CEP290 mRNA levels (FIG. 6E).

[0350] Taken together, these data demonstrate that the self-limiting Crispr-Cas9 system is able to restrict SpCas9 persistence time, remove the LCA10 c.2991+1655A>G mutation, rescue wild-type CEP290 expression, and reduce mutant CEP290 expression.

Example 4: Targeted Deletion of An Intronic Region of Mouse Cep290 Gene In the Mouse Reina

Methods

Plasmids

[0351] We used a dual AAV system for targeted genomic deletion in the mouse retina. The first AAV is produced with the AAV packaging plasmid pAAV-minCMV-SpCas9-NLS- SV40 pA as described above. The second AAV is produced with an AAV packaging plasmid pAAV-U6-Ul l sgRNA-U6-Dl l sgRNA-RK-EGFP-BGH pA. To construct this plasmid, the Ul l sgRNA guide sequence (SEQ ID NO: 61) and Dl l sgRNA guide sequence (SEQ ID NO: 62) were subcloned into pSpCas9(BBUD) plasmid as described above to generate a pSpCas9(BBUD)-Ul 1D11 plasmid. A RK promoter -EGFP-BGH pA fragment (SEQ ID NO: 63) was inserted into the Kpnl and Xhol sites of this plasmid, and then the entire U6-U11 sgRNA-U6-Dl 1 sgRNA-RK-EGFP-BGH pA cassette was cut out from this plasmid using the restriction enzymes Pcil and Pmel and then subcloned into the BamHI and Sphl sites of the AAV packaging plasmid described above to generate the final plasmid. A control plasmid pAAV-RK-EGFP-BGH pA was also generated. AA V production

[0352] Recombinant AAV vectors were produced by triple transfection of human embryonic kidney carcinoma 293 cells (HEK-293) as previously described (Xiao, X. et al. (1998) J. Virol. 72:2224-2232). Briefly, an AAV packaging plasmid, a plasmid containing the rep gene from serotype 2 and a capsid gene from serotype 5, and a helper adenoviral plasmid (Stratagene) were used. Virus was collected 72 hours post-transfection, purified by AVB Sepharose affinity chromatography (GE Healthcare). Genome copy (GC) titers of AAV vectors were determined by TaqMan-based quantitative PCR analysis (Applied Biosystems) as described previously (Gerits, A. et al. (2015) Neurophotonics. 2:031209).

Animals

[0353] 8-10 weeks old female C57BL/6J mice from the Jackson Laboratories (Bar Harbor, ME) were purchased and maintained at Sanofi's vivarium. The animals were given free access to food and water for the duration of the study. All animal procedures were conducted in compliance with the Animal Welfare Act, the Guide for the Care and Use of Laboratory Animals, the Office of Laboratory Animal Welfare, and in accordance to the ARVO

Statement for the Use of Animals in Ophthalmic and Vision Research.

Subretinal AAV injection

[0354] Mice were sedated using 3.5 % isoflurane carried in 800 milliliter/min of oxygen delivered to the animal via a nose cone. Mydriasis and cycloplegia was induced in mice with a topical application of Tropicamide (Alcon, Fort Worth, TX). A pilot incision was made in the cornea and a 33 gauge blunt tipped needle was directed through the incision and advanced posteriorly between the iris and the lens capsule until the tip penetrated the posterior neurosensory retina. lxlO ⁹ viral genome particles of AAV5-minCMV-SpCas9-NLS-SV40 pA (AAV5-SpCas9 in FIG. 7A) together with lxlO ⁹ viral genome particles of AAV5-U6- Ul l sgRNA-U6-Dl l sgRNA-RK-EGFP-BGH pA (AAV5-U1 ID 11 -RK-EGFP in FIG. 7A) or the control AAV5-U6-RK-EGFP-BGH pA (AAV5- RK-EGFP in FIG. 7B) were delivered to the OS eye of each mouse in the volume of one microliter over the time of one second. The needle was held in position for approximately five seconds before withdrawal. The animal was allowed to recover from anesthesia prior to returning to its cage. [0355] EGFP expression in the retina was evaluated in live animals using a Micron IV Retinal Microscope (Phoenix Research Labs) at two and four weeks post-injection, and mice lacking EGFP expression were excluded from the study. All the animals were euthanized at four weeks post-injection.

Retina dissection

[0356] Mouse eyes were enucleated and placed in Phosphate-buffered saline (PBS). Retinas were isolated with micro dissecting scissors under a dissecting microscope. The retinal pigment epithelium (RPE) layer was carefully removed.

Genomic DNA expression and PCR analysis

[0357] Retinas were homogenized in QuickExtract DNA Extraction Solution (Epicentre) with pestles powered by a cordless motor (VWR). Genomic DNA was extracted following manufacturer's instruction (Epicentre), diluted to 10 nanogram/microliter, and then amplified with GoTaq Hot Start Green Master Mix (Promega) and PCR primers flanking the deleted region (SEQ ID NOS: 64-65). Amplification of the PCR products was achieved with the following cycling parameters: 1 cycle at 95°C for 2 min; 35 cycles of 95°C for 30 sec, 62°C for 30 sec, and 72°C for 2 min; 1 cycle at 72°C for 12 min. PCR products were then subjected to agarose gel electrophoresis.

Results

[0358] Our study in the cellular model of LCA10 supported the efficiency of our paired sgRNAs and SpCas9 approach to remove the LCA10 c.2991+1655A>G mutation in vitro. Next, we assessed our CRISPR-Cas9 approach in an in vivo setting. Since currently there is no animal model that expresses the cryptic exon caused by the LCA10 intronic splice mutation, we thus tested if a pair of sgRNAs along with SpCas9 could induce targeted genomic deletion in the intron 25 of mouse Cep290 gene, which is homologous to the intron 26 of human CEP290 gene where the c.2991+1655A>G mutation is located.

[00100] We decided to use AAV vectors for in vivo gene delivery because of their low immunogenicity and range of serotypes allowing preferential infection of certain cell types. The retinal cells most affected by CEP290 mutations are photoreceptors, and previous studies have shown that AAV serotype 5 (AAV5) could efficiently transduce photoreceptors with subretinal injection (Boye, S.E. et al. (2012) Hum. Gene Ther.

23: 1101-1115). Therefore, we decied to use AAV5 to deliver SpCas9 and paired sgRNAs to photoreceptors.

[0359] Due to the low packaging capacity of an AAV vector (-4.8 kb) and the length of SpCas9 coding sequence, measuring in at 4.1 kb (see SEQ ID NO: 40 for amino acid sequence), it is challenging to package one SpCas9 component and two U6-sgRNA components in a single AAV vector. Therefore, we used a dual AAV system for our in vivo validation study (FIG. 7A). The first AAV vector is AAV5-U11D11-RK-EGFP, which expresses an upstream sgRNA Ul l (SEQ ID NO: 61) and a downstream sgRNA Dl l (SEQ ID NO: 62), as well as a rhodopsin kinase (RK) promoter-driven EGFP reporter gene. The Ul l and Dl l sgRNA pair are predicted to generate genomic deletion of 557 bp in the intron 25 of mouse Cep290 gene. A control AAV AAV5-RK-EGFP was also produced. The second AAV vector is AAV5-SpCas9, which expresses a minCMV promoter-driven SpCas9.

[0360] AAV5-U11D11-RK-EGFP (or AAV5-RK-EGFP) and AAV5-SpCas9 (lxlO ⁹ viral genome particles each) were co-injected into the subretinal space of adult C57BL/6J mice. EGFP expression in the retina was evaluated in live animals, and mice lacking EGFP expression were excluded from the study. At four weeks post-injection, the animals were euthanized, and genomic DNA was extracted from the retinas, followed by PCR analysis using primers flanking the deletion regions (SEQ ID NOS: 64-65). Wild-type and truncated genomic fragments were resolved by gel electrophoresis. For the animals injected with AAV5-U11D11-RK-EGFP and AAV5-SpCas9, PCR product was detected that indicates the presence of expected genomic deletion with the Ul l and Dl l sgRNA pair, which was absent in the animals injected with AAV5-RK-EGFP and AAV5-SpCas9 (FIG. 7B). These results demonstrate that our dual AAV system is capable of inducing targeted genomic deletion in vivo.

Example 5: Employing A Pair of Upstream/downstream sgRNAs and SaCas9 to Remove the LCA10 c.2991+1655A>G Mutation

Methods

Plasmids [0361] To construct the SaCas9 plasmid, a minCM V-S aCas9-NLS -FLAG-B GH pA-U6- BsaLBsal-sgRNA scaffold fragment (SEQ ID NO: 66) was synthesized at GenScript and subcloned into the Pcil and Bbsl restriction sites of the Sigma pSpCas9 plasmid to replace the CMV-SpCas9-BGH pA cassette and generate a pminCMV-SaCas9-BGH pA-U6 plasmid. Five sgRNA guide sequences (aUl, aU2, aU3, aDl, aD2; SEQ ID NOS: 45-49) were identified using Benchling's online genome-editing design tool and then subcloned into the two Bsal restriction sites of the above plasmid. To pair up the upstream sgRNAs (aUl, aU2, aU3) and downstream sgRNAs (aDl, aD2), the U6-aDl sgRNA cassette and U6-aD2 sgRNA cassette were cut out from their plasmids using the restriction enzymes Kpnl and Notl, and then subcloned into the Notl site of the plasmid that expresses aUl, aU2, or aU3 sgRNA. As a result, we generated six plasmids that express six different sgRNA pairs (aUlaDl, aUlaD2, aU2aDl, aU2aD2, aU4aDl, aU4aD2). Finally, the minCMV-SaCas9-BGH pA-U6-paired sgRNAs fragments in these six plasmids were subcloned into an AAV packaging plasmid to generate pAAV-minCMV-SaCas9-BGH pA-U6-paired sgRNAs plasmids. A control plasmid pAAV-minCMV-SaCas9-BGH pA that does not express sgRNA was also generated.

Results

[0362] From the above studies we have demonstrated that a pair of upatream/downstream sgRNAs could efficiently guide SpCas9 to remove the LCA10 c.2991+1655A>G mutation and restore wild-type CEP290 expression. The length of SpCas9 coding sequence (~4.1kb) makes it difficult to package one minCMV-SpCas9 component and two U6-sgRNA components in a single AAV vector. Ran et al. (Ran, F.A. et al. (2015) Nature 520: 186-191) recently discovered a shorter Cas9 enzyme S. aureus Cas9 (SaCas9; 1053 amino acids; SEQ ID NO: 55) that also displays cleavage activity in mammalian cells. The smaller size of SaCas9 makes it possible to package one minCMV-SaCas9 component and two U6-sgRNA components in a single AAV vector. To test if paired sgRNAs and SaCas9 are also able to remove the LCA10 intronic mutation, we designed three upstream sgRNA guide sequences (aUl, aU2, aU3; SEQ ID NOS: 45-47) and two downstream sgRNA guide sequences (aDl, aD2; SEQ ID NOS: 48-49) specifically for SaCas9 using Benchling's online genome-editing design tool. The upstream/downstream sgRNAs were paired up and subcloned into the AAV packaging plasmid. The same plasmids also expressed a minCMV promoter-driven and human codon-optimized SaCas9 (SEQ ID NO: 66). [0363] The paired sgRNAs-SaCas9 plasmids were transfected into mutant cells as described above. To compare SaCas9 with SpCas9, mutant cells were also transfected with the dual SpCas9 AAV plasmids (pAAV-minCMV-SpCas9 + pAAV-UlD3 sgRNA pair) or individual plasmids alone. PCR analysis was performed using primers flanking the deletion regions (SEQ ID NOS: 4-5). Wild-type and truncated genomic fragments were resolved by gel electrophoresis. For all the tested upstream/downstream sgRNA pairs, PCR products were detected that indicate the presence of expected genomic deletions, which were absent in the control plasmids-transfected cells (FIG. 8A). These results demonstrate that both SaCas9 and SpCas9 are able to work with paired sgRNAs to remove the LCA10 intronic splice mutation.

[0364] Next, we examined wild-type and mutant CEP290 mRNA levels in mutant cells transfected with above AAV packaging plasmids. Surprisingly, none of the

upstream/downstream sgRNA pairs significantly increased wild-type CEP290 mRNA levels compared to the SaCas9 alone plasmid, although the aU2aDl pair and the aU2aD2 pair showed a trend of increase (FIG. 8B). In contrast, the dual AAV plasmids for SpCas9 significantly rescued wild-type CEP290 mRNA levels compared to individual plasmids (FIG. 8B). All the paired sgRNAs-SaCas9 plasmids significantly reduced mutant CEP290 mRNA levels compared to the SaCas9 alone plasmid (FIG. 8C). Similarly, the dual AAV plasmids for SpCas9 significantly reduced mutant CEP290 mRNA levels compared to individual plasmids (FIG. 8C). Although in the current study SaCas9 is not as efficient as SpCas9 in rescuing wild-type CEP290 mRNA levels in mutant cells, we cannot exclude the possibility that a potent sgRNA pairs may guide SaCas9 to efficiently remove the LCA10 intronic splice mutation and significantly rescue wild-type CEP290 mRNA levels in mutant cells.

SEQUENCES

All nucleic sequences are presented 5' to 3' unless otherwise noted.

All amino acid sequences are presented N-terminus to C-terminus unless otherwise noted.

Top strand oligonucleotide for the sgRNA used in homology-directed repair (HDR) (SEQ ID NO: 1)

caccgAAGACACTGCCAATAGGGAT

Bottom strand oligonucleotide for the sgRNA used in homology-directed repair (HDR) (SEQ ID NO: 2)

aaacATCCCTATTGGCAGTGTCTTc

HDR template (SEQ ID NO: 3)

CCACCCGCCTCGGCCTCCTAAAGTGCTGGGATTACAGATGTGAGCCACCGCACCTGGCCC CAGTTGTAATTGT GAGTATCTCATACGTATCCCTATTGGCAGTGTCTTAGTTTTATTTTTTATTATCTTTATT GTGGCAGCCATTA TTCCTGTCTCTA

CEP290 Intron 26 F nucleic acid primer (SEQ ID NO: 4)

GGTCCCTGGCTTTTGTTCCT

CEP290 Intron 26 R nucleic acid primer (SEQ ID NO: 5)

CAGGAGGCTGAGGGTGTTTT

CEP290 Intron 26 sequencing primer (SEQ ID NO: 6)

AGTAGAGATGGGGTTTCACC

Wild-type CEP290 F nucleic acid primer (SEQ ID NO: 7)

TGACTGCTAAGTACAGGGACATCTTG

Wild-type CEP290 R nucleic acid primer (SEQ ID NO: 8)

AGGAGATGTTTTCACACTCCAGGT

Mutant CEP290 F nucleic acid primer (SEQ ID NO: 9)

CTGGCCCCAGTTGTAATTTGTGA

Mutant CEP290 R nucleic acid primer (SEQ ID NO: 10)

CTGTTCCCAGGCTTGTTCAATAGT

Top strand oligonucleotide for the Ul sgRNA (SEQ ID NO: 11)

caccGGCGGGTGGATCACGAGTTC

Bottom strand oligonucleotide for the Ul sgRNA (SEQ ID NO: 12)

aaacGAACTCGTGATCCACCCGCC

Top strand oligonucleotide for the Dl sgRNA (SEQ ID NO: 13)

caccgAAAGCTACCGGTTACCTGAA

Bottom strand oligonucleotide for the Dl sgRNA (SEQ ID NO: 14)

aaacTTCAGGTAACCGGTAGCTTTc

Top strand oligonucleotide for the D2 sgRNA (SEQ ID NO: 15)

caccgTCATTCTTGTGGCAGTAAGG Bottom strand oligonucleotide for the D2 sgRNA (SEQ ID NO: 16)

aaacCCTTACTGCCACAAGAATGAc

Top strand oligonucleotide for the D3 sgRNA (SEQ ID NO: 17)

caccGGAGTCACATGGGAGTCACA

Bottom strand oligonucleotide for the D3 sgRNA (SEQ ID NO: 18)

aaacTGTGACTCCCATGTGACTCC

Ul sgRNA sequence (SEQ ID NO: 19)

GGCGGGTGGATCACGAGTTCGTTTTAGAGCTAGAAATAGCAAGTTAAAATAAGGCTAGTC CGTTATCAACTTGAAAAAGTG GCACCGAGTCGGTGCTTTTTT

Dl sgRNA sequence (SEQ ID NO: 20)

GAAAGCTACCGGTTACCTGAAGTTTTAGAGCTAGAAATAGCAAGTTAAAATAAGGCTAGT CCGTTATCAACTTGAAAAAGT GGCACCGAGTCGGTGCTTTTTT

D2 sgRNA sequence (SEQ ID NO: 21)

GTCATTCTTGTGGCAGTAAGGGTTTTAGAGCTAGAAATAGCAAGTTAAAATAAGGCTAGT CCGTTATCAACTTGAAAAAGT GGCACCGAGTCGGTGCTTTTTT

D3 sgRNA sequence (SEQ ID NO: 22)

GGAGTCACATGGGAGTCACAGTTTTAGAGCTAGAAATAGCAAGTTAAAATAAGGCTAGTC CGTTATCAACTTG AAAAAGTGGCACCGAGTCGGTGCTTTTTT

CEP290 intron 26 sequence (Note: c.2991+1655A>G mutation is the 1655 ^th nucleotide in this sequence and is bolded and underlined) (SEQ ID NO: 23)

GTAAGTTTGTGTGATTCTTGAACCTTGTGAAATTAGCCATTTTTCTTCAATATTTTTGTG TTTGGGGGGATTT GGCAGATTTTAATTAAAGTTTGCCTGCATTTATATAAATTTAACAGAGATATAATTATCC ATATTATTCATTC AGTTTAGTTATAAATATTTTGTTCCCACATAACACACACACACACACACAATATATTATC TATTTATAGTGGC TGAATGACTTCTGAATGATTATCTAGATCATTCTCCTTAGGTCACTTGCATGATTTAGCT GAATCAAACCTCT TTTAACCAGACATCTAAGAGAAAAAGGAGCATGAAACAGGTAGAATATTGTAATCAAAGG AGGGAAGCACTCA TTAAGTGCCCATCCCTTTCTCTTACCCCTGTACCCAGAACAAACTATTCTCCCATGGTCC CTGGCTTTTGTTC CTTGGAATGGATGTAGCCAACAGTAGCTGAAATATTAAGGGCTCTTCCTGGACCATGGAT GCACTCTGTAAAT TCTCATCATTTTTTATTGTAGAATAAATGTAGAATTTTAATGTAGAATAAATTTATTTAA TGTAGAATAAAAA ATAAAAAAACTAGAGTAGAATATCATAAGTTACAATCTGTGAATATGGACCAGACCCTTT GTAGTTATCTTAC AGCCACTTGAACTCTATACCTTTTACTGAGGACAGAACAAGCTCCTGATTTGTTCATCTT CCTCATCAGAAAT AGAGGCTTATGGATTTTGGATTATTCTTATCTAAGATCCTTTCACAGGAGTAGAATAAGA TCTAATTCTATTA GCTCAAAAGCTTTTGCTGGCTCATAGAGACACATTCAGTAAATGAAAACGTTGTTCTGAG TAGCTTTCAGGAT TCCTACTAAATTATGAGTCATGTTTATCAATATTATTTAGAAGTAATCATAATCAGTTTG CTTTCTGCTGCTT TTGCCAAAGAGAGGTGATTATGTTACTTTTTATAGAAAATTATGCCTATTTAGTGTGGTG ATAATTTATTTTT TTCCATTCTCCATGTCCTCTGTCCTATCCTCTCCAGCATTAGAAAGTCCTAGGCAAGAGA CATCTTGTGGATA ATGTATCAATGAGTGATGTTTAACGTTATCATTTTCCCAAAGAGTATTTTTCATCTTTCC TAAAGATTTTTTT TTTTTTTTTTTGAGATGGAGTTTCATTCTGTCACCCAGGCTGAGTGCAGTGGCACGATCT CGGCTTAACGCTT ACTGCATCCTCTGCCTCCCAGATTCAAGCAGTTCTCCTGCCTCAGCCTCTGAGTAGCTGG GATTACAGGTGTG CACCACCACACCAGCTAATTTTTTTTTTTTTTTTTTTTTTTTTGAGGCAGAGTCTCGCTC TGTCACCCAGGCT GGAGTGCAGTGGCGCCATCTTGGCTCACTGCAAGCTCCACCTCCCGGGTTCAGGCCGTTC TCCTGCCTCAGCC TCCTGAGTAGCTGGTACCACAGGCACCCACCATCATGCCCGGCTAATTTTTTGTATTTTT AGTAGAGATGGGG TTTCACCTTGTTAGCCAGGATGGTGTCGATCTCCTGAACTCGTGATCCACCCGCCTCGGC CTCCTAAAGTGCT GGGATTACAGATGTGAGCCACCGCACCTGGCCCCAGTTGTAATTGTGAGTATCTCATACC TATCCCTATTGGC AGTGTCTTAGTTTTATTTTTTATTATCTTTATTGTGGCAGCCATTATTCCTGTCTCTATC TCCAGTCTTACAT CCTCCTTACTGCCACAAGAATGATCATTCTAAACATGAATCCTACCCTGTGACTCCCATG TGACTCCCCGCCT TAAAAACTGTCAAAAGCTACCGGTTACCTGAAGGGTAAAAGTCAAGTCCCCTACTTACCT CATGTCATCTAGA GCAAGAGATGAACTAGCTGAGTTTTCTGACCACAGTGTTCTTTCTTATGTATGTTCTTTT GTACGTGCTCTTT TCTATATATAGGGAACCATTTCTCTCTTCCAGTTGTTTTGCTCAGTGAATTTCTATTCCT GTTTCAAAACTTG TTCAGGCATTACCTTTTTTTTCTTAAGCATACTTTTTTTAATGGAACAAAGTCACTCCTG TCTACACTAGTTC TGCATCTTATACATAGGTTTTGTACATAGTACATATTTATATCACATCAAATTATATGTG TTTACATATCTGT CTTCCTTAATGGAATATAAGTCTTTTGATATAAGGAACTATTTAATTTGTTTCTGTGTGT TGAGTATCTCCTG TTTGGCACAGAGTTCAAGCTAATACATGAGAGTGATTAGTGGTGGAGAGCCACAGTGCAT GTGGTGTCAAATA TGGTGCTTAGGAAATTATTGTTGCTTTTTGAGAGGTAAAGGTTCATGAGACTAGAGGTCA CGAAAATCAGATT TCATGTGTGAAGAATGGAATAGATAATAAGGAAATACAAAAACTGGATGGGTAATAAAGC AAAAGAAAAACTT GAAATTTGATAGTAGAAGAAAAAAGAAATAGATGTAGATTGAGGTAGAATCAAGAAGAGG ATTCTTTTTTTGT TGTTTTTTTTTTTGAAACAGAGTCTCACTGTGTTGCCCAGGCTGGAGTGCAGTGGAGTGA TCTTGGCTTACTG CAACCTCTGCCTCCCAGGTTCAAGCGATTCTTCTGCTTCAGTCTCCCGAGTAGCTGGAAT TACAGGTGCCCAC CAGCACGGCCGGCTAATTTAGTAGAGACAGGGTTTTGCCATGTTGGCCGGGCTGGTCTCA AACTTTGGATCTC AGGTAATCCGCCAGCCTCAACTTCCCAAAGTGCTGGGATTACAGGCATGAGCCACTGTGC CCAGCCTGTTTTT TTTTTTTTAAAGGAGACCAGTGAAGTTTCAGGAGGAGGGAAAGAAAATTTAGAGTTACTA GGGAGAGAGTGAT GAAGATAAGAGATGAAAGTGGTAATAAGGGAAATAGCAAAATATCAGGGTAGGTGGGAGA AAAAGAGATTTGT AACAAACAATAGGATTATCCTGTGAAAAAGGATGAAAGGAAGAAAAAAATGGATAGAAAG ATATTTAAAACAC CCTCAGCCTCCTGTTTTCCCTCCTGTGTATTCATAGTATATAAAACTATAATTATGTACT TTACTTAAAAAAT ATATTATTATTACCTTATCGTGCTTATTTAATCATAGCATGTCCTCTTTTTAGTCTCATT ACCCTGTTTGTAT TATTCTTCATAACACTTAATACCTGACATTGTATTATATATTGGCTTATTTTCCAGGTAC TCCACTCAAATAT AAGTTCTAGGATATAATTTATTTATCACTGAAATCCATTGCTTAGAGTACCTGGCATGTA GTAAATAGGCATT CTGTTTTTTCAAATAAAAAATAAAGGAACTTAAGATATATATTTATGTTATATCGCCAGC CTTTTTCCTCACA GCTCTATTCTGTTGTACAGAATTACCTACTTTACAATTCCTGTGTTTCAAGGGGATCTCA AATTTAACGTGTC CACAATGAACTCCTGATTTCTGTTTCTCTCCTAGTCATTCTTATTTCAATATATGTTCAG TTACCTAACCAGC TAGTCAAGGCAGATACTTTAGAGTTATTCTGTAGTCATTCTTTTTCCCTACCATTTTTGT TTTCCAAATGTAA TTTATGTGTGTCTTCTTCATCCTCGCAGCTCTAACCCTTGTCCAAACCAGCATCATCACT CATCTGGAGTTCC ACAATGTCTTTCTGGCTAGTTTCCCTGATTTCTCTATTGACCCCTTTATTCTCCACAGTG CAGCCAGAATGAT TGTTTAAAACTTCCTCCTTAAAATCTTTAAATTGTTTTCTTTTATACGTTAAGTTAAATT CCAGTTCCTTGTC TTGGCATGCCATGCCCTGCCTGGTGTGGCCCCTGATGGTCTCTCCAACTTCATGTTTTAC TACTATTGACTCT TATTTTTGCTTACTCTGCTTGGGTGCTCCAGTCCTCCAAATCATTTCCTGCTCCAATCAT TTCAATCATTTTT TCCTCTCAGATCTTATAGTATTCCAAATGCTTTCTTCCTTTGGAGCATCTGGGTTTACTA ATAAATACTTCGT ACCTCACAGTTCAGCTTAAATATCAATTATTTGGTGGTTAAGACATCCTTCAACCGCTCT ATCTAAATGTTCC TTTCTATTATTCACTGGCTCAGTACTCTGTTTTTATTTTCTTTCTAAATGTCAACTTTTT TTTTTTTGAGTCA GGGTCTCACTGTTGCCCAGGCTCGAGTGCAGTTGCACAATCATAGCTCATTGCAGCCTTG CCCTCCTGGGATC AAGTAATTCTCCCACCTCAGCCTCCAAAATAGCTGGGATTACAGGTATGCATCACCATGC TCAGCTAATTTTT TGTGTTTTTTTGTAGAGATGAGGTCTCACTTTGTTGCCCAGGCTGGTCTCAAACTCCTGG ACTCAAGTGATTC TCCCACCTCAGCCTCCCAAAGTGCTGGGGTTACAGGTGTGAGCCACTGCACCTGGTCGAT ACTGACTTTTTTT TTTTTTTGAGATGGAGTTTTGCTCTGTTGCCCAGGCTAGAGCGCAGTGGTGTGATCTCAG CTCACTGCAACCT CCACCTCCCAGGTTAAAGGGATTCTTCTGCCTCAGTCTCCTGAGTAGCTGGGATTACAGG CAAGTGCCATCAT GACTGGCTAATTTTTGTATTTTTAGCACTATGTTTAGTACTGTGTTGGCCAGGCTTGTCT CGAACTCCTGACC TCAAGTGATCCACCCACCTCAGCCTCCCAAAGTGCTGGGATTACAGGTGTGAGCCACCGT AATCGGCCAACAT TGACATTTTTAGTAGACTTTTTGTTTGTTTACTTGCTTATTATCTGCTGCCTTCCACACT CTGGCGAAATCCT GCCACCCACCCACACACACATAGGCACTGAATGGGCAGAACTCTGAAGGCCAGAATTTTA TATTTCTTTTCAC TGTAAACATCATCATCTGTCACTGATGGCACACTAGGATGCTCAGCAACTGTGTGCATGA AGGAAGTAAGCAC TAGTTTGTGAAGGCTGCAAAACTCTTGAGTATTCTAAGAGTTTTGGCCAAAATGAATGTA CAGCTTTAGTGGC AGAAGCTAATACTCAGAAATTGAGGCCGTATATTGGATAACACAGGATTTGGATGATTAT TTTAAAATAATAT TTTACATTGTATATATGTGTGTGTGTGTGTGTGTGTGTGTGTGTATGTGTGTGTGTGTGT ATATATATATGTA TGTATGTGTATTAGTCCGTTCTCATGCTGCTATGAAGAAATACCTGAGACTGGGTAATTT ATAAAGGAAAGAG GTTTAATTGACTCACAGTTCCACAGAGCTGGGGAGGCCTCAGAAAACTTAACAGTTATGG CAGAAGGGGAAGC AAACACATTTTTCTTCACATGGTGGCCGGAATTAGAAGAATGTGAGCCGAGCAAAGGGGA AAGCCCCTTATAA AACCATCAGACATCGTGAGAACTTACTATTATGAGAATAGCGTGGGGGAAACCACCCCCA CGATTCAATTACC TCCCACCAAATCCCTCCCATGACATATGAGGATTATGGGAACTATGATTCAAGATGAGAT TTGGGTAGGGACA CAGCCAAACCATATCAGTATGTATATGTATACAAGTATTATATATATATGTATGTGTTTG TATGCATACATGT ATTATATATGGAGGAAATTCTAATTTTGTAAAAAACTGGATTGTGAGTTTTAAGGAGATG TTATATAAAGTTA AGACAATGTCATTTTGTGGTATTGGTCTGAATTACAATGTAGTTTCTTAGTGATATTTTT CCTTTATTCAG

Mutated ITR sequence (SEQ ID NO: 24)

CACTCCCTCTCTGCGCGCTCGCTCGCTCACTGAGGCCGGGCGACCAAAGGTCGCCCACGC CCGGGCTTTGCCC GGGCG tracr sequence (SEQ ID NO: 25)

TAGCAAGTTAAAATAAGGCTAGTCCGTTATCAACTTGAAAAAGTGGCACCGAGTCGGTGC NLS sequences

PKKKRKV (SEQ ID NO: 26)

PKKKRKVEDPKKKRKVD (SEQ ID NO: 27)

Forward nucleic acid primer for Bbsl restriction site mutation (SEQ ID NO: 28)

GGGAGGATTGGGAAGAGAATAGCAGGCATGCTG

Reverse nucleic acid primer for Bbsl restriction site mutation (SEQ ID NO: 29)

CAGCATGCCTGCTATTCTCTTCCCAATCCTCCC

U6 promoter-BbsLBbsI-sgRNA scaffold-U6 terminator cassette for constructing pSpCas9(BB) with U6 promoter sequence underlined (SEQ ID NO: 30)

CACATGTGAGGGCCTATTTCCCATGATTCCTTCATATTTGCATATACGATACAAGGCTGT TAGAGAGATAAT TGGAATTAATTTGACTGTAAACACAAAGATATTAGTACAAAATACGTGACGTAGAAAGTA ATAATTTCTTGG GTAGTTTGCAGTTTTAAAATTATGTTTTAAAATGGACTATCATATGCTTACCGTAACTTG AAAGTATTTCGA TTTCTTGGCTTTATATATCTTGTGGAAAGGACGAAACACCGGGTCTTCGAGAAGACCTGT TTTAGAGCTAGA AATAGCAAGTTAAAATAAGGCTAGTCCGTTATCAACTTGAAAAAGTGGCACCGAGTCGGT GCTTTTTTGTTT TAGAGCTAGAAATAGCAAGTTAAAATAAGGCTAGTCCGTTTTTAGCGCGTGCGCCAATTC TGCAGACAAATG GCTCTAGAGGTACCC

PPIA F nucleic acid primer (SEQ ID NO: 31)

TTCATCTGCACTGCCAAGAC

PPIA R nucleic acid primer (SEQ ID NO: 32)

TCGAGTTGTCCACAGTCAGC

U6 promoter-BbsLBbsI-sgRNA scaffold-U6 terminator-CMV promoter for constructing pSpCas9(BBU) with U6 promoter and CMV promoter sequence underlined (SEQ ID NO: 33)

CTCACATGTGAGGGCCTATTTCCCATGATTCCTTCATATTTGCATATACGATACAAGGCT GTTAGAGAGATAA TTGGAATTAATTTGACTGTAAACACAAAGATATTAGTACAAAATACGTGACGTAGAAAGT AATAATTTCTTGG GTAGTTTGCAGTTTTAAAATTATGTTTTAAAATGGACTATCATATGCTTACCGTAACTTG AAAGTATTTCGAT TTCTTGGCTTTATATATCTTGTGGAAAGGACGAAACACCGGGTCTTCGAGAAGACCTGTT TTAGAGCTAGAAA TAGCAAGTTAAAATAAGGCTAGTCCGTTATCAACTTGAAAAAGTGGCACCGAGTCGGTGC TTTTTTGTTTTAG AGCTAGAAATAGCAAGTTAAAATAAGGCTAGTCCGTTTTTAGCGCGTGCGCCAATTCTGC AGACAAATGGCTC TAGAGACCGGCGCCGCTACAGGCTTTCCACCGGTGGTCTCTTCTAGAGGTACCCGTTACA TCTAGTTATTAAT AGTAATCAATTACGGGGTCATTAGTTCATAGCCCATATATGGAGTTCCGCGTTACATAAC TTACGGTAAATGG CCCGCCTGGCTGACCGCCCAACGACCCCCGCCCATTGACGTCAATAATGACGTATGTTCC CATAGTAACGCCA ATAGGGACTTTCCATTGACGTCAATGGGTGGAGTATTTACGGTAAACTGCCCACTTGGCA GTACATCAAGTGT ATCATATGCCAAGTACGCCCCCTATTGACGTCAATGACGGTAAATGGCCCGCCTGGCATT ATGCCCAGTACAT GACCTTATGGGACTTTCCTACTTGGCAGTACATCTACGTATTAGTCATCGCTATTACCAT GGTGATGCGGTTT TGGCAGTACATCAATGGGCGTGGATAGCGGTTTGACTCACGGGGATTTCCAAGTCTCCAC CCCATTGACGTCA ATGGGAGTTTGTTTTGGCACCAAAATCAACGGGACTTTCCAAAATGTCGTAACAACTCCG CCCCATTGACGCA AATGGGCGGTAGGCGTGTACGGTGGGAGGTCTATATAAGCAGAGCTCTCTGGCTAACTAG AGAACCCACTGCT TACTGGCTTATCGAAATTAATACGACTCACTATAGGGAGAACCAAGCTGGCTAGCCGC

Forward nucleic acid primer for constructing pSpCas9(BBD) (SEQ ID NO: 34)

ATAACATGTGGTCTCACTCTAGAGGCATGTGAGGGCCTATTTCCC

Reverse nucleic acid primer for constructing pSpCas9(BBD) (SEQ ID NO: 35)

TATGGTACCGGTCTCATAGAGCCATTTGTCTGCAGA

Top strand oligonucleotide for the control 1 sgRNA (SEQ ID NO: 36)

caccGCACTACCAGAGCTAACTCA

Bottom strand oligonucleotide for the control 1 sgRNA (SEQ ID NO: 37)

aaacTGAGTTAGCTCTGGTAGTGC Top strand oligonucleotide for the control 2 sgRNA (SEQ ID NO: 38)

caccgTGCGAATACGCCACGCGAT

Bottom strand oligonucleotide for the control 2 sgRNA (SEQ ID NO: 39)

aaacATCGCGTGGCGTATTCGCAc

S. pyogenes Cas9 amino acid sequence (SEQ ID NO: 40)

MDKKYSIGLDIGTNSVGWAVITDEYKVPSKKFKVLGNTDRHSIKKNLIGALLFDSGETAE ATRLKRTARRRYT RRKNRICYLQEIFSNEMAKVDDSFFHRLEESFLVEEDKKHERHP IFGNIVDEVAYHEKYPTIYHLRKKLVDST DKADLRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENP INASGVDAKAILSARLSKS RRLENLIAQLPGEKKNGLFGNLIALSLGLTPNFKSNFDLAEDAKLQLSKDTYDDDLDNLL AQIGDQYADLFLA AKNLSDAILLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEIFF DQSKNGYAGYIDG GASQEEFYKFIKP ILEKMDGTEELLVKLNREDLLRKQRTFDNGS IPHQIHLGELHAILRRQEDFYPFLKDNRE KIEKILTFRIPYYVGPLARGNSRFAWMTRKSEETITPWNFEEWDKGASAQSFIERMTNFD KNLPNEKVLPKH SLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVDLLFKTNRKVTVKQLKEDYFKK IECFDSVEI SGVE DRFNASLGTYHDLLKI IKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQLKRRRYT GWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDDSLTFKEDIQKAQVSGQG DSLHEHIANLAGS PAIKKGILQTVKWDELVKVMGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKEL GSQILKEHPVEN TQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVDHIVPQSFLKDDS IDNKVLTRSDKNRGKSDNVPSEEW KKMKNYWRQLLNAKLITQRKFDNLTKAERGGLSELDKAGFIKRQLVETRQITKHVAQILD SRMNTKYDENDKL IREVKVITLKSKLVSDFRKDFQFYKVREINNYHHAHDAYLNAWGTALIKKYPKLESEFVY GDYKVYDVRKMI AKSEQEIGKATAKYFFYSNIMNFFKTEITLANGEIRKRPLIETNGETGEIVWDKGRDFAT VRKVLSMPQVNIV KKTEVQTGGFSKES ILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLWAKVEKGKSKKLKSVKELLGITI MERSSFEKNP IDFLEAKGYKEVKKDLI IKLPKYSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASH YEKLKGSPEDNEQKQLFVEQHKHYLDEI IEQI SEFSKRVILADANLDKVLSAYNKHRDKP IREQAENI IHLFT LTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQS ITGLYETRIDLSQLGGD

Ul sgRNA guide/protospacer sequence (SEQ ID NO: 41)

GGCGGGTGGATCACGAGTTC

Dl sgRNA guide/protospacer sequence (SEQ ID NO: 42)

AAAGCTACCGGTTACCTGAA

D2 sgRNA guide/protospacer sequence (SEQ ID NO: 43)

TCATTCTTGTGGCAGTAAGG

D3 sgRNA guide/protospacer sequence (SEQ ID NO: 44)

GGAGTCACATGGGAGTCACA

aUl sgRNA guide/protospacer sequence (SEQ ID NO: 45)

TTTAACGTTATCATTTTCCCA

aU2 sgRNA guide/protospacer sequence (SEQ ID NO: 46)

AGTTTCATTCTGTCACCCAGG

aU3 sgRNA guide/protospacer sequence (SEQ ID NO: 47)

AAAAATTAGCCGGGCATGATG

aDl sgRNA guide/protospacer sequence (SEQ ID NO: 48)

TGTAAGACTGGAGATAGAGAC

aD2 sgRNA guide/protospacer sequence (SEQ ID NO: 49)

CTTTTGACAGTTTTTAAGGCG

aUl sgRNA sequence (SEQ ID NO: 50) GTTTAACGTTATCATTTTCCCAGTTTTAGTACTCTGGAAACAGAATCTACTAAAACAAGG CAAAATGCCGTGTTTATCTCG TCAACTTGTTGGCGAGATTTTT

aU2 sgRNA sequence (SEQ ID NO: 51)

GAGTTTCATTCTGTCACCCAGGGTTTTAGTACTCTGGAAACAGAATCTACTAAAACAAGG CAAAATGCCGTGTTTATCTCG TCAACTTGTTGGCGAGATTTTT

aU3 sgRNA sequence (SEQ ID NO: 52)

GAAAAATTAGCCGGGCATGATGGTTTTAGTACTCTGGAAACAGAATCTACTAAAACAAGG CAAAATGCCGTGTTTATCTCG TCAACTTGTTGGCGAGATTTTT

aDl sgRNA sequence (SEQ ID NO: 53)

GTGTAAGACTGGAGATAGAGACGTTTTAGTACTCTGGAAACAGAATCTACTAAAACAAGG CAAAATGCCGTGTTTATCTCG TCAACTTGTTGGCGAGATTTTT

aD2 sgRNA sequence (SEQ ID NO: 54)

GCTTTTGACAGTTTTTAAGGCGGTTTTAGTACTCTGGAAACAGAATCTACTAAAACAAGG CAAAATGCCGTGTTTATCTCG TCAACTTGTTGGCGAGATTTTT

S. aureus Cas9 amino acid sequence (SEQ ID NO: 55)

MKRNYI LGLD I GI TSVGYGI IDYETRDVIDAGVRLFKEANVENNEGRRSKRGARRLKRRRRHRIQRVKKLLFD YNLLTDHSELSGINPYEARVKGLSQKLSEEEFSAALLHLAKRRGVHNVNEVEEDTGNELS TKEQI SRNSKALE EKYVAELQLERLKKDGEVRGS INRFKTSDYVKEAKQLLKVQKAYHQLDQSF IDTYIDLLETRRTYYEGPGEGS PFGWKD IKEWYEMLMGHCTYFPEELRSVKYAYNADLYNALNDLNNLVI TRDENEKLEYYEKFQI IENVFKQKK KPTLKQIAKE I LVNEED IKGYRVTSTGKPEFTNLKVYHD IKD I TARKE I IENAELLDQIAKI LT IYQS SED IQ EELTNLNSELTQEE IEQI SNLKGYTGTHNLSLKAINL I LDELWHTNDNQIAIFNRLKLVPKKVDLSQQKE IPT TLVDDF I LSPWKRSF IQS IKVINAI IKKYGLPND I I IELAREKNSKDAQKMINEMQKRNRQTNERIEE I IRT TGKENAKYL IEKIKLHDMQEGKCLYSLEAIPLEDLLNNPFNYEVDHI IPRSVSFDNSFNNKVLVKQEENSKKG NRTPFQYLS S SDSKI SYETFKKHI LNLAKGKGRI SKTKKEYLLEERD INRFSVQKDF INRNLVDTRYATRGLM NLLRSYFRVNNLDVKVKS INGGFTSFLRRKWKFKKERNKGYKHHAEDAL I IANADF IFKEWKKLDKAKKVMEN QMFEEKQAESMPE IETEQEYKE IF I TPHQIKHIKDFKDYKYSHRVDKKPNREL INDTLYSTRKDDKGNTL IVN NLNGLYDKDNDKLKKL INKSPEKLLMYHHDPQTYQKLKL IMEQYGDEKNPLYKYYEETGNYLTKYSKKDNGPV IKKIKYYGNKLNAHLD I TDDYPNSRNKWKLSLKPYRFDVYLDNGVYKFVTVKNLDVIKKENYYEVNSKCYEE AKKLKKI SNQAEF IASFYNNDL IKINGELYRVI GVNNDLLNRIEVNMID I TYREYLENMNDKRPPRI IKT IAS KTQS IKKYSTD I LGNLYEVKSKKHPQI IKKG minCMV promoter-SpCas9 sequence for constructing pAAV-minCMV-SpCas9-NLS- SV40 pA with minCMV promoter underlined (SEQ ID NO: 56)

TATACGCGTGTTGACACTAGTTCGCGAAATATTGACTCACGGGGATTTCCAAGTCTCCAC CCCATTGACGTCA ATGGGAGTTTGTTTTGGCACCAAAATCAACGGGACTTTCCAAAATGTCGTAACAACTCCG CCCCATTGACGCA AATGGGCGGTAGGCGTGTACGGTGGGAGGTCTATATAAGCAGAGCTCGTTTAGTGAACCG TCAGATCGCCGCC ACCATGGACAAGAAGTACAGCATCGGCCTGGACATCGGCACCAACTCTGTGGGCTGGGCC GTGATCACCGACG AGTACAAGGTGCCCAGCAAGAAATTCAAG

SV40 pA sequence for constructing pAAV-minCMV-SpCas9-NLS-SV40 pA with SV40

early poly(A) signal underlined (SEQ ID NO: 57)

T GAC T C GAGAACTTGTTTATTGCAGCTTATAATGGTTACAAATAAAGCAATAGCATCACAAATTTC ACAAATA AAGCATTTTTTTCACTGCATTCTAGTTGTGGTTTGTCCAAACTCATCAATGTATCTTATC ATGTCTGCAATAT TTCGCGAGAAGACAATAGCAGG

Ul sgRNA recognition sequence (U1T; Ul sgRNA guide sequence + PAM) (SEQ ID NO:

58)

GGCGGGTGGATCACGAGTTCAGG

D3 sgRNA recognition sequence (D3T; D3 sgRNA guide sequence + PAM) (SEQ ID NO:

59)

GGAGTCACATGGGAGTCACAGGG BGH pA-containing fragment with BGH pA underlined (SEQ ID NO: 60)

CTAGTGGCGGCCGCTCGAGCATGCATCTAGAGGGCCCTATTCTATAGTGTCACCTAA ATGCTAGAGCTCGCTG ATCAGCCTCGACTGTGCCTTCTAGTTGCCAGCCATCTGTTGTTTGCCCCTCCCCCGTGCC TTCCTTGACCCTG GAAGGTGCCACTCCCACTGTCCTTTCCTAATAAAATGAGGAAATTGCATCGCATTGTCTG AGTAGGTGTCATT CTATTCTGGGGGGTGGGGTGGGGCAGGACAGCAAGGGGGAGGATTGGGAAGACAATAGCA GGCATGCTGGGGA GCTAGAGTCGACCGGACCGCTGCAGGCATGCA

Ul l sgRNA guide/protospacer sequence (SEQ ID NO: 61)

GCATAAGGACTAAAGACCTA

Dl l sgRNA guide/protospacer sequence (SEQ ID NO: 62)

GGTAGTGGTTGAACTCACAA

RK promoter-Chimeric intron-EGFP-BGH pA fragment (SEQ ID NO: 63)

GGGCCCCAGAAGCCTGGTGGTTGTTTGTCCTTCTCAGGGGAAAAGTGAGGCGGCCCCTTG GAGGAAGGGGCCG GGCAGAATGATCTAATCGGATTCCAAGCAGCTCAGGGGATTGTCTTTTTCTAGCACCTTC TTGCCACTCCTAA GCGTCCTCCGTGACCCCGGCTGGGATTTAGCCTGGTGCTGTGTCAGCCCCGGTCTCCCAG GGGCTTCCCAGTG GTCCCCAGGAACCCTCGACAGGGCCCGGTCTCTCTCGTCCAGCAAGGGCAGGGACGGGCC ACAGGCCAAGGGC GGAGTCGCTGCGACGCTGCCTTCGCCCCGTGCCCCGCTCCGCCGCCGCCTCGCGCCGCCC GCCCCGGCTCTGA CTGACCGCGTTACTCCCACAGGTGAGCGGGCGGGACGGCCCTTCTCCTCCGGGCTGTAAT TAGCGCTTGGTTT AATGACGGCTTGTTTCTTTTCTGTGGCTGCGTGAAAGCCTTGAGGGGCTCCGGGAGGGCC CTTTGTGCGGGGG GAGCGGCTCGGGGGGTGCGTGCGTGTGTGTGTGCGTGGGGAGCGCCGCGTGCGGCTCCGC GCTGCCCGGCGGC TGTGAGCGCTGCGGGCGCGGCGCGGGGCTTTGTGCGCTCCGCAGTGTGCGCGAGGGGAGC GCGGCCGGGGGCG GTGCCCCGCGGTGCGGGGGGGGCTGCGAGGGGAACAAAGGCTGCGTGCGGGGTGTGTGCG TGGGGGGGTGAGC AGGGGGTGTGGGCGCGTCGGTCGGGCTGCAACCCCCCCTGCACCCCCCTCCCCGAGTTGC TGAGCACGGCCCG GCTTCGGGTGCGGGGCTCCGTACGGGGCGTGGCGCGGGGCTCGCCGTGCCGGGCGGGGGG TGGCGGCAGGTGG GGGTGCCGGGCGGGGCGGGGCCGCCTCGGGCCGGGGAGGGCTCGGGGGAGGGGCGCGGCG GCCCCCGGAGCGC CGGCGGCTGTCGAGGCGCGGCGAGCCGCAGCCATTGCCTTTTATGGTAATCGTGCGAGAG GGCGCAGGGACTT CCTTTGTCCCAAATCTGTGCGGAGCCGAAATCTGGGAGGCGCCGCCGCACCCCCTCTAGC GGGCGCGGGGCGA AGCGGTGCGGCGCCGGCAGGAAGGAAATGGGCGGGGAGGGCCTTCGTGCGTCGCCGCGCC GCCGTCCCCTTCT CCCTCTCCAGCCTCGGGGCTGTCCGCGGGGGGACGGCTGCCTTCGGGGGGGACGGGGCAG GGCGGGGTTCGGC TTCTGGCGTGTGACCGGCGGCTCTAGAGCCTCTGCTAACCATGTTCATGCCTTCTTCTTT TTCCTACAGCTCC TGGGCAACGTGCTGGTTATTGTGCTGTCTCATCATTTTGGCAAAGAATTCTTCGAAAGAT CTGCTAGCTTAAT TAACCCGGTCGCCACCATGGTGAGCAAGGGCGAGGAGCTGTTCACCGGGGTGGTGCCCAT CCTGGTCGAGCTG GACGGCGACGTAAACGGCCACAAGTTCAGCGTGTCCGGCGAGGGCGAGGGCGATGCCACC TACGGCAAGCTGA CCCTGAAGTTCATCTGCACCACCGGCAAGCTGCCCGTGCCCTGGCCCACCCTCGTGACCA CCCTGACCTACGG CGTGCAGTGCTTCAGCCGCTACCCCGACCACATGAAGCAGCACGACTTCTTCAAGTCCGC CATGCCCGAAGGC TACGTCCAGGAGCGCACCATCTTCTTCAAGGACGACGGCAACTACAAGACCCGCGCCGAG GTGAAGTTCGAGG GCGACACCCTGGTGAACCGCATCGAGCTGAAGGGCATCGACTTCAAGGAGGACGGCAACA TCCTGGGGCACAA GCTGGAGTACAACTACAACAGCCACAACGTCTATATCATGGCCGACAAGCAGAAGAACGG CATCAAGGTGAAC TTCAAGATCCGCCACAACATCGAGGACGGCAGCGTGCAGCTCGCCGACCACTACCAGCAG AACACCCCCATCG GCGACGGCCCCGTGCTGCTGCCCGACAACCACTACCTGAGCACCCAGTCCGCCCTGAGCA AAGACCCCAACGA GAAGCGCGATCACATGGTCCTGCTGGAGTTCGTGACCGCCGCCGGGATCACTCTCGGCAT GGACGAGCTGTAC AAGTAAAGCGGCCAAATCGTACGCCTAGGTGATCAAGATCTGCTAGCTTAATTAACCCGG GACTAGTGGCGGC CGCTCGAGCATGCATCTAGAGGGCCCTATTCTATAGTGTCACCTAAATGCTAGAGCTCGC TGATCAGCCTCGA CTGTGCCTTCTAGTTGCCAGCCATCTGTTGTTTGCCCCTCCCCCGTGCCTTCCTTGACCC TGGAAGGTGCCAC TCCCACTGTCCTTTCCTAATAAAATGAGGAAATTGCATCGCATTGTCTGAGTAGGTGTCA TTCTATTCTGGGG GGTGGGGTGGGGCAGGACAGCAAGGGGGAGGATTGGGAAGACAATAGCAGGCATGCTGGG GA

Mouse Cep290 Intron 25 F nucleic acid primer (SEQ ID NO: 64)

CCCCTCGCCTGTACTGAAAG

Mouse Cep290 Intron 25 R nucleic acid primer (SEQ ID NO: 65)

GCACATCATCTGAGGCAGGT

minCM V-S aCas9-NLS -FLAG-B GH pA-U6-BsaI:BsaI-sgRNA scaffold fragment with minCMV and SaCas9 sequence underlined (SEQ ID NO: 66) ATGAATTCTCTAGACAATTGGACTCACGGGGATTTCCAAGTCTCCACCCCATTGACGTCA ATGGGAGTTTGTT TTGGCACCAAAATCAACGGGACTTTCCAAAATGTCGTAACAACTCCGCCCCATTGACGCA AATGGGCGGTAGG CGTGTACGGTGGGAGGTCTATATAAGCAGAGCTCGTTTAGTGAACCGTCAGATCACGCGT GCCACCATGAAGC GGAACTACATCCTGGGCCTGGACATCGGCATCACCAGCGTGGGCTACGGCATCATCGACT ACGAGACACGGGA CGT GAT C GAT GCCGGCGTGCGGCTGTTCAAAGAGGCCAACGTGGAAAACAACGAGGGCAGGCGGAGCAA GAGA GGCGCCAGAAGGCTGAAGCGGCGGAGGCGGCATAGAATCCAGAGAGTGAAGAAGCTGCTG TTCGACTACAACC TGCTGACCGACCACAGCGAGCTGAGCGGCATCAACCCCTACGAGGCCAGAGTGAAGGGCC TGAGCCAGAAGCT GAGCGAGGAAGAGTTCTCTGCCGCCCTGCTGCACCTGGCCAAGAGAAGAGGCGTGCACAA CGTGAACGAGGTG GAAGAGGACACCGGCAACGAGCTGTCCACCAAAGAGCAGATCAGCCGGAACAGCAAGGCC CTGGAAGAGAAAT ACGTGGCCGAACTGCAGCTGGAACGGCTGAAGAAAGACGGCGAAGTGCGGGGCAGCATCA ACAGATTCAAGAC CAGCGACTACGTGAAAGAAGCCAAACAGCTGCTGAAGGTGCAGAAGGCCTACCACCAGCT GGACCAGAGCTTC ATCGACACCTACATCGACCTGCTGGAAACCCGGCGGACCTACTATGAGGGACCTGGCGAG GGCAGCCCCTTCG GCTGGAAGGACATCAAAGAATGGTACGAGATGCTGATGGGCCACTGCACCTACTTCCCCG AGGAACTGCGGAG CGTGAAGTACGCCTACAACGCCGACCTGTACAACGCCCTGAACGACCTGAACAATCTCGT GATCACCAGGGAC GAGAACGAGAAGCTGGAATATTACGAGAAGTTCCAGATCATCGAGAACGTGTTCAAGCAG AAGAAGAAGCCCA CCCTGAAGCAGATCGCCAAAGAAATCCTCGTGAACGAAGAGGATATTAAGGGCTACAGAG TGACCAGCACCGG CAAGCCCGAGTTCACCAACCTGAAGGTGTACCACGACATCAAGGACATTACCGCCCGGAA AGAGATTATTGAG AACGCCGAGCTGCTGGATCAGATTGCCAAGATCCTGACCATCTACCAGAGCAGCGAGGAC ATCCAGGAAGAAC TGACCAATCTGAACTCCGAGCTGACCCAGGAAGAGATCGAGCAGATCTCTAATCTGAAGG GCTATACCGGCAC CCACAACCTGAGCCTGAAGGCCATCAACCTGATCCTGGACGAGCTGTGGCACACCAACGA CAACCAGATCGCT ATCTTCAACCGGCTGAAGCTGGTGCCCAAGAAGGTGGACCTGTCCCAGCAGAAAGAGATC CCCACCACCCTGG TGGACGACTTCATCCTGAGCCCCGTCGTGAAGAGAAGCTTCATCCAGAGCATCAAAGTGA TCAACGCCATCAT CAAGAAGTACGGCCTGCCCAACGACATCATTATCGAGCTGGCCCGCGAGAAGAACTCCAA GGACGCCCAGAAA ATGATCAACGAGATGCAGAAGCGGAACCGGCAGACCAACGAGCGGATCGAGGAAATCATC CGGACCACCGGCA AAGAGAACGCCAAGTACCTGATCGAGAAGATCAAGCTGCACGACATGCAGGAAGGCAAGT GCCTGTACAGCCT GGAAGCCATCCCTCTGGAAGATCTGCTGAACAACCCCTTCAACTATGAGGTGGACCACAT CATCCCCAGAAGC GTGTCCTTCGACAACAGCTTCAACAACAAGGTGCTCGTGAAGCAGGAAGAAAACAGCAAG AAGGGCAACCGGA CCCCATTCCAGTACCTGAGCAGCAGCGACAGCAAGATCAGCTACGAAACCTTCAAGAAGC ACATCCTGAATCT GGCCAAGGGCAAGGGCAGAATCAGCAAGACCAAGAAAGAGTATCTGCTGGAAGAACGGGA CATCAACAGGTTC TCCGTGCAGAAAGACTTCATCAACCGGAACCTGGTGGATACCAGATACGCCACCAGAGGC CTGATGAACCTGC TGCGGAGCTACTTCAGAGTGAACAACCTGGACGTGAAAGTGAAGTCCATCAATGGCGGCT TCACCAGCTTTCT GCGGCGGAAGTGGAAGTTTAAGAAAGAGCGGAACAAGGGGTACAAGCACCACGCCGAGGA CGCCCTGATCATT GCCAACGCCGATTTCATCTTCAAAGAGTGGAAGAAACTGGACAAGGCCAAAAAAGTGATG GAAAACCAGATGT TCGAGGAAAAGCAGGCCGAGAGCATGCCCGAGATCGAAACCGAGCAGGAGTACAAAGAGA TCTTCATCACCCC CCACCAGATCAAGCACATTAAGGACTTCAAGGACTACAAGTACAGCCACCGGGTGGACAA GAAGCCTAATAGA GAGCTGATTAACGACACCCTGTACTCCACCCGGAAGGACGACAAGGGCAACACCCTGATC GTGAACAATCTGA ACGGCCTGTACGACAAGGACAATGACAAGCTGAAAAAGCTGATCAACAAGAGCCCCGAAA AGCTGCTGATGTA CCACCACGACCCCCAGACCTACCAGAAACTGAAGCTGATTATGGAACAGTACGGCGACGA GAAGAATCCCCTG TACAAGTACTACGAGGAAACCGGGAACTACCTGACCAAGTACTCCAAAAAGGACAACGGC CCCGTGATCAAGA AGATTAAGTATTACGGCAACAAACTGAACGCCCATCTGGACATCACCGACGACTACCCCA ACAGCAGAAACAA GGTCGTGAAGCTGTCCCTGAAGCCCTACAGATTCGACGTGTACCTGGACAATGGCGTGTA CAAGTTCGTGACC GTGAAGAATCTGGATGTGATCAAAAAAGAAAACTACTACGAAGTGAATAGCAAGTGCTAT GAGGAAGCTAAGA AGCTGAAGAAGATCAGCAACCAGGCCGAGTTTATCGCCTCCTTCTACAACAACGATCTGA TCAAGATCAACGG CGAGCTGTATAGAGTGATCGGCGTGAACAACGACCTGCTGAACCGGATCGAAGTGAACAT GATCGACATCACC TACCGCGAGTACCTGGAAAACATGAACGACAAGAGGCCCCCCAGGATCATTAAGACAATC GCCTCCAAGACCC AGAGCATTAAGAAGTACAGCACAGACATTCTGGGCAACCTGTATGAAGTGAAATCTAAGA AGCACCCTCAGAT CATCAAAAAGGGCGGATCCCCCAAGAAAAAGCGCAAAGTGGACTACAAAGACGATGACGA CAAGTGAGCTAGC GACTGTGCCTTCTAGTTGCCAGCCATCTGTTGTTTGCCCCTCCCCCGTGCCTTCCTTGAC CCTGGAAGGTGCC ACTCCCACTGTCCTTTCCTAATAAAATGAGGAAATTGCATCGCATTGTCTGAGTAGGTGT CATTCTATTCTGG GGGGTGGGGTGGGGCAGGACAGCAAGGGGGAGGATTGGGAAGAGAATAGCAGGCATGCTG GTACCTGAGGGCC TATTTCCCATGATTCCTTCATATTTGCATATACGATACAAGGCTGTTAGAGAGATAATTG GAATTAATTTGAC TGTAAACACAAAGATATTAGTACAAAATACGTGACGTAGAAAGTAATAATTTCTTGGGTA GTTTGCAGTTTTA AAATTATGTTTTAAAATGGACTATCATATGCTTACCGTAACTTGAAAGTATTTCGATTTC TTGGCTTTATATA TCTTGTGGAAAGGACGAAACACCGGAGACCACGGCAGGTCTCAGTTTTAGTACTCTGGAA ACAGAATCTACTA AAACAAGGCAAAATGCCGTGTTTATCTCGTCAACTTGTTGGCGAGATTTTTGCGGCCGCG TCGACAT