In this context, the inventors have chosen to explore the appearance of white hair, or canities, from a completely new angle, that of genetics. in fact, exploring canities from the point of view of its genetics makes it possible to identify the underlying mechanisms of depigmentation. That also makes it possible to identify the genes that are implicated in canities. This identification opens the door to very many applications in the field of hair care, whether cosmetic, therapeutic or diagnostic.

It is highly innovative to try to identify the regions of the genome responsible for canities by genetic linkage analysis whereas other studies are concerned with deciphering the biochemistry of canities.

The inventors have chosen to take advantage of the hypothesis suggested a long time ago of the hereditary character of premature canities (PC), or the appearance of white hair early in life. The familial character of premature whitening of the hair in certain people is in fact readily observable.

The second obstacle to the implementation of reverse genetics relates to the precise definition of the phenotype. A complete definition of the phenotype under study is in fact necessary. In order to guarantee the best chances of success for the identification of the genes in this case, the choice and composition of the sample used in the present invention are the result of the application of a rigorous protocol for the assignment of the phenotype and the selection of the families. The"premature canities"phenotype was assigned only to individuals who had white hair before 25 years of age and half of whose scalp hair was grey at 30 years of age.

In addition, it is probable that, on the one hand, the premature canities has a multigenic, and not a monogenic, origin and, on the other hand, that environmental factors have an influence on the phenotype. In fact the subject requires the definition of a set of causes that predispose to premature canities rather than the search for a single mutation responsible for the phenotype. In this context, reverse genetics is not usually a procedure recommended by geneticists. It is therefore original on the part of the inventors to have used this method.

The results of this work have enabled the inventors to define chromosomal and/or genetic regions implicated with high probability in canities. In the present application the regions of the chromosomes or the subparts of these regions, identified by the inventors as statistically implicated in canities, will be designated indiscriminately"chromosomal regions of the invention"or"genomic regions of the invention"or"chromosomal areas of the invention"or "genomic areas of the invention".

The object of the present invention relates, on the one hand, to the chromosomal regions identified and, on the other hand, to the use of products derived, such as the products of transcription or translation, in the fields of cosmetics, therapeutics and diagnostics. in the case of the fields of therapy and cosmetics, the present invention relates successively to the use of polynucleotides derived from a chromosomal region of the invention, the use of agents capable of modifying the function attached to a region of the invention, the use of expression products of region of the invention and the use of agents capable of modifying the function of these expression products. The joint or combined use of at least two of the preceding products may prove to be sensible, in particular in the therapeutic field.

The present invention also relates to a process for the diagnosis of premature canities based on the allelic variations within the chromosomal regions of the invention. As far as diagnostics is concerned, it may in addition be particularly judicious to combine the information derived from different chromosomal areas of the invention.

GLOSSARY In the context of the present invention the terms used have the following meaning: By polynucleotide fragment is meant any molecule resulting from the linear linking of at least two nucleotides, this molecule being single-stranded, doube-stranded or triple- stranded. It may therefore be a double-stranded DNA molecule, a single-stranded DNA molecule, an RNA, a duplex of single-stranded DNA-RNA, a DNA-RNA triplex or any other combination. The polynucleotide fragment may be naturally occurring, recombinant or also synthetic. When the polynucleotide fragment comprises complementary strands, the complementarity is not necessarily perfect, but the affinity between the different strands is sufficient to allow the establishment of stable links of the Watson-Crick type between the two strands.

Although the matching of the bases is preferably of the Watson-Crick type, other types are not excluded, such as a matching of the Hoogsteen type or reverse Hoogsteen type.

It is considered that the sequence S of a molecule"corresponds"to the sequence of a given DNA molecule if it is possible to deduce the sequence of the bases of S from that of the given DNA molecule by one of the following processes 1. by identity, or 2. by identity but by changing all or some of the thymines to uracils, or 3. by complementarity, or 4. by complementarity but by changing all or some of the thymines to uraciis.

In addition, it is considered that two sequences remain"corresponding"if overall less than one error in ten is introduced in one of the preceding processes (complementarity or identity, with or without T, U exchange), and preferably less than one error in 100. Consequently, the two molecules also necessarily have similar lengths, the maximum variation in length being 10% according to the accepted level of error, they preferably have a difference in length of less than 1%.

This definition does not assume that the two molecules are of the same kind, in particular as regards their skeleton, there is uniquely a correspondence between their sequences.

For example, two identical DNA sequences"correspond"to each other.

Similarly, if these two sequences are substantially identical, i. e. identical to more than 90%, they correspond to each other. An RNA sequence, derived from the transcription of any DNA molecule,"corresponds"to the sequence of this DNA molecule. Similarly, a synthetic sequence, for example a DNA-RNA hybrid, may correspond to a DNA sequence. The same holds true between a DNA sequence and the anti-sense RNA that targets this sequence.

In the same schema, it is considered that the sequence S of a DNA molecule"corresponds" to the sequence of a given DNA molecule if it is possible to deduce the sequence S from that of the given DNA molecule by the process 1 or 3 uniquely. The same latitude is allowed concerning the possibility of introducing errors in to these processes, i. e. that it is considered that two DNA sequences remain"corresponding"if overall less than one error in 10 is introduced in the processes of complementarity or of identity, and preferably less than one error in 100.

The expression products of a DNA fragment include all of the molecules translating the genetic information borne by this fragment. The RNAs corresponding to the transcription of the DNA fragment, at all stages of maturation, are thus expression products; the same is true for the polypeptides, at all stages of maturation, resulting from the translation of the RNAs. If cleavages arise within the polypeptide, as for example the cleavage of the address signals, all of the resulting polypeptides are also considered as expression products of the initial DNA fragment.

In the context of the invention, the primary"function"of a DNA fragment is preferably to be transcribed, then translated into protein. The secondary function of the DNA may be assimilated to the function of the protein resulting from the translation of this DNA. The function of a DNA fragment also takes on other meanings in the present invention. In particular, a DNA fragment may belong to a regulatory region of a gene, its function is then either to be the binding site of enhancers or inhibitors or to be the binding site of the RNA polymerase or to be a recognition site for the positioning of the RNA polymerase, or any other function usually ascribed to a regulatory sequence.

Other functions can be imagined for the DNA fragments. In particular, the simple fact of their being present within a gene may facilitate recombinations. Similarly, a function according to the invention may be that of telomers and be related to degeneration. Other particular functions assigned to DNA fragments are well-known to biologists.

A genetic marker is a detectable DNA sequence. In human genetics, markers are specific sequences of the DNA that are capable of assuming different forms depending on the individuals. This polymorphism of the markers makes it possible to follow their transmission in the context of genealogical trees.

Among the conventional markers, mention may be made of the markers which exhibit a restriction fragment length polymorphism. This type of polymorphism is designated a RFLP (Restriction Fragment Length Polymorphism).

A microsatellite is a repeated DNA sequence, constituted of a relatively simple motif: most frequently a di-, tri-or tetranucleotide. The number of repetitions changes for the same motif depending on the individuals and may vary from several units (a dozen at least for a dinucleotide) up to more than one hundred. These sequences are scattered more or less everywhere throughout the genome in an almost random manner but at sites identical from one individual to another. They are very abundant (about one every 10,000 nucleotides = 10 kb) and they are very polymorphic. It is the variation in length of the tandem repeat which constitutes the marker. These microsatellite sequences are hence very much used as genetic markers.

Usually, there is no explicit link between a microsatellite marker and a gene, except a co- localisation. According to present knowledge and apart from a few rare cases of intragenic markers associated with certain diseases, the length of a tandem repeat is unrelated to the role of a gene. In the context of the present invention, the microsatellite markers are tools for localising the genes implicated in premature canities. As there is much less polymorphism in the genes than in the markers, a genic allele will be represented by several alleles of the same microsatellite marker.

There are different methods for defining the localisation of specific DNA sequences along the chromosomes. The physical unit of measure is the number of base pairs. However, the centimorgan is often used, that is a unit of recombination, thus a genetic unit of measure and not a physical one. Two specific sequences of a same chromosome are separated by a centimorgan if they recombine once per hundred during meiosis. A centimorgan is approximately equivalent to 106 base pairs.

Another method for localising specific DNA sequences along the chromosomes consists of defining their position relative to markers lining the chromosomes and the position of which is completely defined and known. Very much used markers are microsatellite markers for which very complete mappings exist. In particular the GDB"Genome Database"is a data bank, known worldwide to index among other things the STSs (Sequence tagged sites), specific and unique landmarks on the DNA of which the microsatellites form part. The DxSxxxx codes (for example D6S257), serving to identify these markers, are their access number in GDB. These codes are an unambiguous and universal means of identification because only GDB assigns this type of code. As such microsatellite markers can be found about every 10 kb, it is thus possible to define the position of every sequence to about 10 kb, by indicating the microsatellite markers framing it.

By chromosomal region between two markers is meant the entire sequence included between these two markers, the limits, thus the sequence of the markers, being included.

In reverse genetics, the indices making it possible to localise a gene originate from the comparison of the transmission of a phenotype, supposedly induced by a mutated gene or by a given allele, with the transmission of known markers within the same family. These co- segregation data of a phenotype and a marker make it possible to establish a genetic linkage analysis.

The co-transmission of a phenotype and a marker suggest that the gene responsible for the phenotype and the marker are physically close to each other on the chromosome. The linkage is defined by the analysis of the transmission schema of a gene and a marker in families that lend themselves to it.

The linkage analysis is based on the co-transmission of certain forms of markers with the defective or modified form of a gene. But it is an indirect analysis in the sense that, on the one hand, during a first step, a phenotype is associated with the defective or modified form of a gene. An error in the assignment of certain phenotypes distorts the study. On the other hand, this study is based on statistics, these statistics being based on the analysis of a sample of the population, it is thus a survey. Finally, it should be noted that when it is possible to associate a particular allele of the marker with an allele of the gene (in fact a phenotype), this association is a priori only valid for inter-familial samples.

The result of the linkage analyses obviously depends on the degree of linkage between the marker and the locus of the disease. Five centimorgans (5 cM) is considered as a linkage minimum for a diagnosis. A linkage of 5 cM signifies that there are 95% chances to arrive at a correct conclusion and only one chance in 20 that a recombination has occurred between the marker and the locus of the disease.

The inventors had previously identified five distinct chromosomal regions belonging to the chromosomes 6,3, 5,9 and 11 and which are implicated in premature canities. The inventors have now identified 22 distinct novel chromosomal regions, belonging to the chromosomes 1,2, 3,4, 6,7, 9,10, 12,15, 16,18, 19,20. Each of these 22 regions are the chromosomal regions or areas of the invention.

According to a first feature or aspect, the invention relates to the region of human chromosome 1 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This first chromosomal area of the invention is delimited on chromosome 1 by the microsatellite markers D1S2797 and D1S2868. This area will be more specifically designated "first chromosomal area of the invention".

According to a second feature or aspect, the invention relates to the region of human chromosome 1 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This second chromosomal area of the invention is delimited on chromosome 1 by the microsatellite marker D1S2842 and the telomer q. This area will be more specifically designated"second chromosomal area of the invention".

According to a third feature or aspect, the invention relates to the region of human chromosome 1 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This third chromosomal area of the invention is delimited on chromosome 1 by the microsatellite markers D1S2667 and D1S199. This area will be more specifically designated "third chromosomal area of the invention".

According to a fourth feature or aspect, the invention relates to the region of human chromosome 2 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This fourth chromosomal area of the invention is delimited on chromosome 2 by the microsatellite markers D2S149 and D2S392. This area will be more specifically designated"fourth chromosomal area of the invention".

According to a fifth feature or aspect, the invention relates to the region of human chromosome 2 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This fifth chromosomal area of the invention is delimited on chromosome 2 by the microsatellite markers D2S347 and D2S142. This area will be more specifically designated "fifth chromosomal area of the invention".

According to a sixth feature or aspect, the invention relates to the region of human chromosome 3 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This sixth chromosomal area of the invention is delimited on chromosome 3 by the microsatellite markers D3S3567 and D3S1277. This area will be more specifically designated "sixth chromosomal area of the invention".

According to a seventh feature or aspect, the invention relates to the region of human chromosome 3 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This seventh chromosomal area of the invention is delimited on chromosome 3 by the microsatellite markers D3S1285 and D3S3653. This area will be more specifically designated"seventh chromosomal area of the invention".

According to an eighth feature or aspect, the invention relates to the region of human chromosome 4 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This eighth chromosomal area of the invention is delimited on chromosome 4 by the microsatellite markers D4S1501 and D4S408. This area will be more specifically designated"eighth chromosomal area of the invention".

According to a ninth feature or aspect, the invention relates to the region of human chromosome 6 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This ninth chromosomal area of the invention is delimited on chromosome 6 by the microsatellite markers D6S308 and D6S1581. This area will be more specifically designated "ninth chromosomal area of the invention".

According to a tenth feature or aspect, the invention relates to the region of human chromosome 7 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This tenth chromosomal area of the invention is delimited on chromosome 7 by the microsatellite markers D7S657 and D7S530. This area will be more specifically designated "tenth chromosomal area of the invention".

According to an 11th feature or aspect, the invention relates to the region of human chromosome 7 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as products of transcription or expression products. This 11th chromosomal area of the invention is delimited on chromosome 7 by the microsatellite markers D7S1824 and D7S615. This area will be more specifically designated"11th chromosomal area of the invention".

According to a 12th feature or aspect, the invention relates to the region of human chromosome 9 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 12th chromosomal area of the invention is delimited on chromosome 9 by the microsatellite markers D9S1677 and D9S1682. This area will be more specifically designated "12th chromosomal area of the invention".

According to a 13th feature or aspect, the invention relates to the region of human chromosome 10 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 13th chromosomal area of the invention is delimited on chromosome 10 by the microsatellite markers D10S591 and D10S547. This area will be more specifically designated "13th chromosomal area of the invention".

According to a 14"'feature or aspect, the invention relates to the region of human chromosome 12 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 14th chromosomal area of the invention is delimited on chromosome 12 by the microsatellite markers D12S310 and D12S85. This area will be more specifically designated "14th chromosomal area of the invention".

According to a 1 5th feature or aspect, the invention relates to the region of human chromosome 12 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 15th chromosomal area of the invention is delimited on chromosome 12 by the microsatellite markers D12S99 and D12S364. This area will be more specifically designated "15th chromosomal area of the invention".

According to a 16th feature or aspect, the invention relates to the region of human chromosome 15 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 16th chromosomal area of the invention is delimited on chromosome 15 by the microsatellite markers D15S1040 and D15S641. This area will be more specifically designated"16th chromosomal area of the invention".

According to a 17'"feature or aspect, the invention relates to the region of human chromosome 15 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 17th chromosomal area of the invention is delimited on chromosome 15 by the microsatellite markers D15S978 and D15S153. This area will be more specifically designated "17th chromosomal area of the invention".

According to an 18th feature or aspect, the invention relates to the region of human chromosome 16 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 18th chromosomal area of the invention is delimited on chromosome 16 by the microsatellite markers D16S503 and D16S516. This area will be more specifically designated "18"chromosomal area of the invention".

According to a 19th feature or aspect, the invention relates to the region of human chromosome 16 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 19th chromosomal area of the invention is delimited on chromosome 16 by the microsatellite markers D16S3030 and D16S501. This area will be more specifically designated"19th chromosomal area of the invention".

According to a 20th feature or aspect, the invention relates to the region of human chromosome 18 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 20th chromosomal area of the invention is delimited on chromosome 18 by the microsatellite markers D18S464 and D18S1102. This area will be more specifically designated"20t chromosomal area of the invention".

According to a 215t feature or aspect, the invention relates to the region of human chromosome 19 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as transcription or expression products. This 215t chromosomal area of the invention is delimited on chromosome 19 by the microsatellite markers D19S216 and D19S221. This area will be more specifically designated "21set chromosomal area of the invention".

According to a 22"d feature or aspect, the invention relates to the region of human chromosome 20 identified by the inventors as being implicated in premature canities and to the uses of the products derived from this region, such as products of transcription or expression products. This 22nd chromosomal area of the invention is delimited on chromosome 20 by the microsatellite markers D20S107 and D20S100. This area will be more specifically designated"22 chromosomal area of the invention".

For the 22 chromosomal areas identified above, the present invention covers polynucleotide fragments having a minimal length of 18 nucleotides, corresponding at least partially to one of the chromosomal areas of the invention, these DNA fragments having the functional characteristic of being implicated in canities or in premature canities and possibly in both phenomena.

According to a possibility envisaged by the present invention, a fragment implicated in canities or premature canities and possessing a sequence meeting the requirements mentioned above may be used in therapy.

More particularly, according to the first aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the first chromosomal area of the invention delimited on chromosome 1 by the microsatellite markers D1S2797 and D1S2868. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D1S2797 and D1S2890, or that delimited by the markers D1S2890 and D1S230, or that delimited by the markers D1S230 and D1S2841, or that delimited by the markers D1S2841 and D1S207, or that delimited by the markers D1S207 and D1S2868, included in the first chromosomal area of the invention.

According to the second aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the second chromosomal area of the invention delimited on chromosome 1 by the microsatellite markers D1S2842 and the telomer q. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D1S2842 and D1S836, or that delimited by the markers D1S836 and the telomer q, included in the second chromosomal area of the invention.

According to the third aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the third chromosomal area of the invention delimited on chromosome 1 by the microsatellite markers D1S2667 and D1S199.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D1S2667 and D1S2697, or that delimited by the markers D1S2697 and D1S199, included in the third chromosomal area of the invention.

According to the fourth aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the fourth chromosomal area of the invention delimited on chromosome 2 by the microsatellite markers D2S149 and D2S392.

According to the fifth aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the fifth chromosomal area of the invention delimited on chromosome 2 by the microsatellite markers D2S347 and D2S142.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D2S347 and D2S112, or that delimited by the markers D2S112 and D2S151, or that delimited by the markers D2S151 and D2S142, included in the fifth chromosomal area of the invention.

According to the sixth aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the sixth chromosomal area of the invention delimited on chromosome 3 by the microsatellite markers D3S3567 and D3S1277.

According to the seventh aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the seventh chromosomal area of the invention delimited on chromosome 3 by the microsatellite markers D3S1285 and D3S3653. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D3S1285 and D3S1566, or that delimited by the markers D3S1566 and D3S3653, included in the seventh chromosomal area of the invention.

According to the eighth aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the eighth chromosomal area of the invention delimited on chromosome 4 by the microsatellite markers D4S1501 and D4S408.

According to the ninth aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the ninth chromosomal area of the invention delimited on chromosome 6 by the microsatellite markers D6S308 and D6S1581.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D6S308 and D6S441, or that delimited by the markers D6S441 and D6S1581, included in the ninth chromosomal area of the invention.

According to the 10aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 10t chromosomal area of the invention delimited on chromosome 7 by the microsatellite markers D7S657 and D7S530.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence deiimited by the markers D7S657 and D7S515, or that delimited by the markers D7S515 and D7S486, or that delimited by the markers D7S486 and D7S530, included in the 10th chromosomal area of the invention.

According to the 11aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 11th chromosomal area of the invention delimited on chromosome 7 by the microsatellite markers D7S1824 and D7S615.

According to the 12aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 12th chromosomal area of the invention delimited on chromosome 9 by the microsatellite markers D9S1677 and D9S1682.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D9S1677 and D9S1776, or that delimited by the markers D9S1776 and D9S1682, included in the 12th chromosomal area of the invention.

According to the 13aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 13th chromosomal area of the invention delimited on chromosome 10 by the microsatellite markers D10S591 and D10S547. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D10S591 and D10S189, or that delimited by the markers D10S189 and D10S547, included in the 13th chromosomal area of the invention.

According to the 14th aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 14th chromosomal area of the invention delimited on chromosome 12 by the microsatellite markers D12S310 and D12S85.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D12S310 and D12S1617, or that delimited by the markers D12S1617 and D12S345, or that delimited by the markers D12S345 and D12S85, included in the 14'h chromosomal area of the invention.

According to the 15th aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 15t chromosomal area of the invention delimited on chromosome 12 by the microsatellite markers D12S99 and. D12S364.

Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D12S99 and D12S336, or that delimited by the markers D12S336 and D12S364, included in the 15th chromosomal area of the invention.

According to the 16aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 16'"chromosomal area of the invention delimited on chromosome 15 by the microsatellite markers D15S1040 and D15S641.

According to the 17th aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 17t chromosomal area of the invention delimited on chromosome 15 by the microsatellite markers D15S978 and D15S153. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D15S978 and D15S117, or that delimited by the markers D15S117 and D15S153, included in the 17th chromosomal area of the invention.

According to the 18th aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 18th chromosomal area of the invention delimited on chromosome 16 by the microsatellite markers D16S503 and D16S516. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D16S503 and D16S515, or that delimited by the markers D16S515 and D16S516, included in the 18th chromosomal area of the invention.

According to the 19aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 19th chromosomal area of the invention delimited on chromosome 16 by the microsatellite markers D16S3030 and D16S501.

According to the 20aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 20th chromosomal area of the invention delimited on chromosome 18 by the microsatellite markers D18S464 and D18S1102. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D18S464 and D18S531, or that delimited by the markers D18S531 and D18S478, or that delimited by the markers D18S478 and D18S1102, included in the 20th chromosomal area of the invention.

According to the 21set aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 21"chromosomal area of the invention delimited on chromosome 19 by the microsatellite markers D19S216 and D19S221. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D19S216 and D19S884, or that delimited by the markers D19S884 and D19S221, included in the 21St chromosomal area of the invention.

According to the 22nd aspect of the invention, a fragment such as that covered by the invention has a sequence corresponding to all or part of the 22nd chromosomal area of the invention delimited on chromosome 20 by the microsatellite markers D20S107 and D20S100. Preferably, the fragments thus defined have a sequence corresponding to all or part of the sequence delimited by the markers D20S107 and D20S119, or that delimited by the markers D20S119 and D20S178, or that delimited by the markers D20S178 and D20S196, or that delimited by the markers D20S196 and D20S100, included in the 22nd chromosomal area of the invention.

The polynucleotide fragment to which reference is made in the context of the invention corresponds to a fragment of a chromosome. This fragment has a minimal length of 18 nucleotides and a maximal length which may extend to the entire length of the chromosomal area in question. Preferably, the fragment has a number of nucleotides greater than 18. A particularly preferred length is included between 18 and 10,000 nucleotides, and preferably between 30 and 8,000 nucleotides.

According to preferred variants of the invention, reference is made to fragments, the length of which is included between 30 and 500 nucleotides, preferably between 50 and 3000 nucleotides, for example between 100 and 2000 nucleotides, or between 200 and 1000 nucleotides.

The invention also relates to the use in cosmetics or in therapy of a polynucleotide fragment or of the expression product of a fragment or of an agent modulating the function of a fragment, or of an agent modulating the function of the expression product of a fragment, where the fragment in question corresponds to all or part of one of the 22 chromosomal areas of the invention. According to a preferred case, the fragment corresponds more particularly to at least a part of a gene, included in one of the 22 chromosomal areas of the invention. In a particular case of this situation, it is all or part of an exon of a gene included in one of the 22 chromosomal areas of the invention.

In what follows, the fragment, the expression product of a fragment, the agent modulating the function of a fragment and the agent modulating the function of the expression product of a polynucleotide fragment corresponding to all or part of one of the 22 chromosomal areas of the invention will be designated as"products of the invention".

In the case of these 22 chromosomal areas, the present invention relates firstly to uses in the field of cosmetics. By cosmetics is meant any application which tends to modify only the aesthetics and has no therapeutic objective.

For all of the uses according to the invention in the field of cosmetics, the product of the invention may be packaged in different appropriate forms, alone or in combination with other agents. In particular, preferred forms are designed for topical applications and they relate to creams, lotions, gels, emulsions, ointments and shampoos. Other forms can also be envisaged for uses according to the invention, in particular in the form of pills for oral administration.

Of the different cosmetic objectives in the context of the present invention, a particularly preferred field is that of pigmentation. Pigmentation may be that of the skin or the phanera. lt may concern the colour of the pigmentation just as the absence of pigmentation; the problems affecting the quality and the intensity of the pigmentation are also concerned by the present invention.

In particular, the object of the invention relates to the use of at least one product of the invention for preventing and/or limiting and/or stopping the development of canities.

The object of the invention also relates to the use of at least one product of the invention to promote the natural pigmentation of the grey scalp and/or body hair.

Another object of the present invention relates to a cosmetic procedure for the treatment of canities characterised in that a composition comprising at least one product of the invention is applied to the area to be treated.

The invention also relates to a cosmetic treatment procedure designed to promote the natural pigmentation of grey or white scalp and/or body hair characterised in that a composition comprising at least one product of the invention is applied to the area to be treated.

The areas to be treated may be, for example and without any limitation, the scalp, the eyebrows, the moustache and/or the beard.

More particularly, the treatment procedures for canities and the natural pigmentation of grey or white scalp and/or body hair consist in applying a composition comprising at least one product of the invention.

The treatment procedures for combating canities and/or for stimulating the natural pigmentation of the grey or white scalp and/or body hair may consist in applying the composition to the hair and the scalp in the evening, maintaining the composition in contact throughout the night and possibly shampooing the hair in the morning or washing the hair with the aid of this composition and leaving it in contact with the hair again for a few minutes before rinsing. The composition in conformity with the invention was shown to be particularly useful when it is applied in the form of a hair lotion, possibly rinsed or even in the form of a shampoo.

In the case of the 22 chromosomal areas identified as so-called"chromosomal areas of the invention", the present invention then relates to therapeutic uses in the field of pigmentation.

The ailments affecting the pigmentation system, whether that of the skin or that of the phanera, may have serious consequences for the health of the persons affected. In fact, the pigmentation of the skin plays the role of protective barrier against stresses due to sunlight in particular, the persons suffering from albinism lack protection against sunlight which constitutes a great danger for them. Other ailments implicating the pigmentation are also concerned by the present invention.

In the context of therapeutic and cosmetic uses tending to modify a characteristic of the pigmentation, it is the pigmentation of the skin which is preferably concerned. According to other cases envisaged by the invention, the type of pigmentation which need to be modified concerns the pigmentation of the phanera, in particular the nails or the body hair.

According to a preferred particular case of the invention, the pigmentation whose characteristics one tries to modify is that of the pilose system in general and in particular that of the head, hair, moustache and eyebrows. The invention makes it possible to modify the phenomenon whereby the pigmentation of the hair ceases, i. e. canities, in particular when the latter occurs prematurely in a person and when one speaks of premature canities.

In the case of all therapeutic uses, the active products entering into the composition of a medicine are preferably combined with pharmaceutically acceptable excipients. All routes of administration considered as acceptable may be used in the context of the invention, in particular by the intradermal, intravenous, muscular, oral, otic, nasal and optic route. The formulation is preferably adapted to the chosen route of administration.

The uses for the manufacture of a medicine according to the invention may implicate other active ingredients in their formulation. Similarly, the administration of a medicine as defined in the invention may be combined with the administration of another medicine, whether this administration is simultaneous, sequential or separated.

Similarly, the different products which are used in the context of the uses in therapy may be combined and enter into the composition of a single medicine or may be used in the manufacture of different medicines. In particular, if they enter into the composition of separate medicines, they may be administered at different frequencies.

The characteristics and the preferred variants of the products which are employed in the uses according to the invention may be identical in the context of the uses in cosmetology and for uses of the same product in the manufacture of a medicine.

In both cases, the use of products according to the invention may require that the product is introduced into a body fluid or into tissues or into cells. For introduction into cells, the use may anticipate that the product is active in the cytoplasm of the cells or in the cell nucleus.

The first use, cosmetic or therapeutic, envisaged in the context of the invention is the use of a polynucleotide fragment, the sequence of which corresponds at least in part to one of the 22 chromosomal areas of the invention. In the case of the therapeutic uses, the polynucleotide fragment enters into the manufacture of a medicine.

As regards the chemical nature of this polynucleotide fragment, it may be a DNA molecule, single-or double-stranded, circular or linear, an RNA molecule or any other molecule envisaged in the definition of polynucleotide fragment given above.

As regards its environment, this fragment may be or form part of a plasmid, a viral genome or another type of vector. In other cases, it may form part of the genome of a cell or of a cell genetically modified to include this fragment in its genome. It may also be an isolated molecule.

As regards the regions framing this fragment, it is preferably under the control of regulatory sequences. If the fragment is inserted in a vector, the said vector preferably comprises all of the sequences necessary for the transcription and possibly the translation of the fragment.

This fragment may also be surrounded by flanking regions making possible a step of homologous recombination with another polynucleotide fragment, possibly leading to the insertion of the fragment of the invention into the genomic DNA of a target cell.

The polynucleotide fragment such as described may be naturally occurring or be synthetic, or be in part one and in part the other, in particular if it is a"duplex"molecule constituted of two strands of different origins. According to different cases envisaged by the present invention, the polynucleotide fragment may have been isolated, it may have undergone a purification step. It may also be a recombinant fragment, for example synthesised in another organism. According to a preferred example, it is a DNA fragment that has been amplified by PCR (Polymerisation Chain Reaction), then purified.

According to other constructions envisaged by the present invention, the first use employs a polynucleotide fragment associated with a probe. This characteristic may make it possible, among other things, to monitor the localisation of the fragment, from the extracellular medium to the cell or from the cytoplasm to the nucleus or to specify its interaction with the DNA or the RNA or proteins. The probe may also make it possible to monitor the degradation of the fragment. The nature of the probe is preferably fluorescent, radioactive or enzymatic. The specialist skilled in the art will know which probe is the best suited as a function of the characteristic that he wishes to be able to monitor.

The polynucleotide fragment, which is employed in the context of this first use according to the invention, may be used in a hybridization test, sequencing, microsequencing or a test for the detection of mismatching.

This fragment according to the invention contains at least 18 successive nucleotides, these 18 nucleotides constituting a sequence which corresponds to all or part of the region of the human chromosome 1 included between the markers D1S2797 and D1 S2868, or to all or part of the region of the human chromosome 1 included between the marker D1S2842 and the telomer q, or to all or part of the region of the human chromosome 1 included between the markers D1S2667 and D1S199, or to all or part of the region of the human chromosome 2 included between the markers D2S149 and D2S392, or to all or part of the region of the human chromosome 2 included between the markers D2S347 and D2S142, or to all or part of the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, or to all or part of the region of the human chromosome 3 included between the markers D3S1285 and D3S3653, or to all or part of the region of the human chromosome 4 included between the markers D4S1501 and D4S408, or to all or part of the region of the human chromosome 6 included between the markers D6S308 and D6S1581, or to all or part of the region of the human chromosome 7 included between the markers D7S657 and D7S530, or to all or part of the region of the human chromosome 7 included between the markers D7S1824 and D7S615, or to all or part of the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, or to all or part of the region of the human chromosome 10 included between the markers D10S591 and D10S547, or to all or part of the region of the human chromosome 12 included between the markers D12S310 and D12S85, or to all or part of the region of the human chromosome 12 included between the markers D12S99 and D12S364, or to all or part of the region of the human chromosome 15 included between the markers D15S1040 and D15S641, or to all or part of the region of the human chromosome 15 included between the markers D15S978 and D15S153, or to all or part of the region of the human chromosome 16 included between the markers D16S503 and D16S516, or to all or part of the region of the human chromosome 16 included between the markers D16S3030 and D16S501, or to all or part of the region of the human chromosome 18 included between the markers D18S464 and D18S1102, or to all or part of the region of the human chromosome 19 included between the markers D19S216 and D19S221, or to all or part of the region of the human chromosome 20 included between the markers D20S107 and D20S100. In particular, a fragment according to the invention may only contain 18 bases complementary to 18 successive bases of one of the 22 chromosomal regions previously described.

According to another particular case, the fragment described may be the cDNA or the RNA of one of the chromosomal regions previously described. It may correspond to one or several exons of one of the regions of the invention, it may correspond to a regulatory sequence included in one of the regions identified on the chromosomes 1,2, 3,4, 6,7, 9, 10,12, 15,16, 18, 19, 20.

In the context of this first use, the number of polynucleotide fragments such as previously defined is not limited and is not necessarily restricted to only one.

In particular, use may be made of several polynucleotide fragments the sequence of which corresponds, at least in part, to the first chromosomal area of the invention. Preferably, the sequences of the different fragments correspond to distinct regions of the first chromosomal area of the invention, for example distinct exons.

Alternatively, use may be made of several polynucleotide fragments, the sequence of which corresponds, at least in part, to the second chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 3rd chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 4th chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the fifth chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the sixth chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 7th chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the eighth chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the ninth chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 10i chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 11'"chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 12t chromosoma) area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 13t"chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 14th chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 15th chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 16th chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 17'h chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 18t chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 19'h chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 20"chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 21St chromosomal area of the invention, or several polynucleotide fragments the sequence of which corresponds, at least in part, to the 22"d chromosomal area of the invention.

However, in the context of this first use, the different polynucleotide fragments which are used all have at least a part of their sequence corresponding to the same chromosomal region of the invention.

This first use according to the invention is preferably in the field of cosmetics.

This use may also make possible the manufacture of a medicine for a therapeutic action in the field of pigmentation.

According to a particular case envisaged, the first use described implies a genetic modification, whether it is induced by a nucleotide fragment such as described or not.

In the case where a gene responsible for pigmentation is defective because it has undergone mutation, this first use according to the invention makes it possible to restore the function of this gene by introducing a polynucleotide fragment which represents a new wildtyp copy of the defective endogenous gene.

In the case where the activation of a gene is responsible for the depigmentation, this first use according to the invention makes it possible to abolish the function of this gene by introducing an antisense RNA which will block the translation of the said gene.

A second use envisaged by the present invention in the field of therapy and cosmetics is the use of an agent modulating the function of a DNA fragment corresponding at least in part to one of the chromosomal areas of the invention. In the case of the therapeutic uses, the agent thus defined enters into the manufacture of a medicament. Preferably, the DNA fragment possesses at least 18 nucleotides.

Such an agent according to the invention may be capable of modulating the function of an exogenous DNA fragment, a part of the sequence of which corresponds to one of the 22 chromosomal areas of the invention identified by the inventors, or it may be capable of modulating the function of an endogenous sequence included in one of these 22 chromosomal areas of the invention. Preferably, an agent being used for this second use according to the invention modulates not only the function of an exogenous DNA fragment such as defined, but also the corresponding endogenous DNA fragment.

The DNA fragment, the function of which is modulated may correspond partially to the first chromosomal region of the invention. Alternatively, the DNA fragment, the function of which is modulated may correspond partially to the 2nd chromosomal region of the invention, or the 3rd 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 1th, 20th, 21st or 22nd chromosomal region of the invention. In particular, it may be a plasmid having uniquely a short sequence corresponding to one of the chromosomal regions mentioned. Preferably, the correspondence of the sequences is established over at least 18 successive nucleotides.

All of the preceding remarks, in the definition part concerning what needs to be understood by"function of a DNA fragment"are valid when considering all of the uses corresponding to a second use according to the invention.

Given the multiplicity of functions of the DNA fragments, the modulation of these functions comprises very different features. In the particular case in which the function of the said fragment is to be transcribed, modulating such a function consists in promoting or inhibiting the capacity of the said fragment to be transcribed. That may also consist in modifying the initiation or termination site of transcription or in modifying the initiation level of transcription.

According to another case, modulating the function may also consist in modifying the splicing of the RNA, for example by modifying recognition signals of the DNA responsible for the distribution between introns and exons.

When the DNA fragment belongs to a regulatory sequence, modifying its function may consist in inhibiting the binding of enhancers or inhibitors. It may consist, on the other hand, in promoting their binding or in promoting the binding of other transcription factors. The same holds when sequences used by the RNA polymerase are concerned.

In the context of this use according to the invention, as in the framework of all of the other uses according to the invention, the number of products, in this case agents modulating the function of a DNA fragment corresponding at least in part to one of the 22 chromosomal regions of the invention, is not limited and may be greater than one.

However, in the context of this second use, the different agents that are used all have in common the capacity to modulate the function of DNA fragments the sequence of which belongs or corresponds to at least a part of the same chromosomal region of the invention.

According to the first feature of the invention, this region is that of the human chromosome 1 identified by the inventors between the markers D1S2797 and D1S2868. According to the other features of the present invention, the chromosomal region in question is that identified by the inventors on the human chromosome 1 included between the markers D1S2842 and the telomer q, or that of the human chromosome 1 included between the markers D1S2667 and D1S199, or that of the human chromosome 2 included between the markers D2S149 and D2S392, or that of the human chromosome 2 included between the markers D2S347 and D2S142, or that of the human chromosome 3 included between the markers D3S3567 and D3S1277, or that of the human chromosome 3 included between the markers D3S1285 and D3S3653, or that of the human chromosome 4 included between the markers D4S1501 and D4S408, or that of the human chromosome 6 included between the markers D6S308 and D6S1581, or that of the human chromosome 7 included between the markers D7S657 and D7S530, or that of the human chromosome 7 included between the markers D7S1824 and D7S615, or that of the human chromosome 9 included between the markers D9S1677 and D9S1682, or that of the human chromosome 10 included between the markers D10S591 and D10S547, or that of the human chromosome 12 included between the markers D12S310 and D12S85, or that of the human chromosome 12 included between the markers D12S99 and D12S364, or that of the human chromosome 15 included between the markers D15S1040 and D15S641, or that of the human chromosome 15 included between the markers D15S978 and D15S153, or that of the human chromosome 16 included between the markers D16S503 and D16S516, or that of the human chromosome 16 included between the markers D16S3030 and D16S501, or that of the human chromosome 18 included between the markers D18S464 and D18S1102, or that of the human chromosome 19 included between the markers D19S216 and D19S221, or that of the human chromosome 20 included between the markers D20S107 and D20S100.

Agents according to the invention are for example single-stranded DNA molecules capable of binding to defined subregions of one of the 22 chromosomal regions of the invention.

Preferably, agents according to the invention are enhancers or inhibitors that bind to regulatory regions of the region of the human chromosome 1 included between the markers D 1 S2797 and D 1 S2868.

Alternatively, agents according to the invention are enhancers or inhibitors that bind to regulatory regions of the region of the human chromosome 1 included between the markers D1S2842 and the telomer q, or the region of the human chromosome 1 included between the markers D1S2667 and D1S199, or of the region of the human chromosome 2 included between the markers D2S149 and D2S392, or of the region of the human chromosome 2 included between the markers D2S347 and D2S142, or of the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, or of the region of the human chromosome 3 included between the markers D3S1285 and D3S3653, or of the region of the human chromosome 4 included between the markers D4S1501 and D4S408, or of the region of the human chromosome 6 included between the markers D6S308 and D6S1581, or of the region of the human chromosome 7 included between the markers D7S657 and D7S530, or of the region of the human chromosome 7 included between the markers D7S1824 and D7S615, or of the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, or of the region of the human chromosome 10 included between the markers D10S591 and D10S547, or of the region of the human chromosome 12 included between the markers D12S310 and D12S85, or of the region of the human chromosome 12 included between the markers D12S99 and D12S364, or of the region of the human chromosome 15 included between the markers D15S1040 and D15S641, or of the region of the human chromosome 15 included between the markers D15S978 and D15S153, or of the region of the human chromosome 16 included between the markers D16S503 and D16S516, or of the region of the human chromosome 16 included between the markers D16S3030 and D16S501, or of the region of the human chromosome 18 included between the markers D18S464 and D18S1102, or of the region of the human chromosome 19 included between the markers D19S216 and D19S221, or of the region of the human chromosome 20 included between the markers D20S107 and D20S100.

Another class of agents according to the invention relates to molecules capable of interacting with specific regions of the DNA and leading to a change in the conformation of the latter. Another class relates to molecules that interact with inhibitors or enhancers and modify their function, the initial function of the inhibitors or enhancers being to modify the expression of DNA fragments belonging to one of the 22 chromosomal regions of the invention.

An agent that is used according to this second use of the invention may in particular modulate the function of a DNA fragment corresponding to 18 successive bases of one of the 22 chromosomal regions previously described.

This second use according to the invention is preferably in the field of cosmetics.

This use may also make possible the manufacture of a medicine with a therapeutic action in the field of pigmentation.

According to particular case envisaged, the second use described implies a genetic modification, whether it is induced by an agent modulating the function of a DNA fragment such as described or not.

In the case in which the activation of a gene is responsible for depigmentation, this second use according to the invention makes it possible to abolish the function of this gene by introducing an agent that will block the translation of the said gene by binding, for example, to its promoter region.

In the case in which the inactivation of a gene is responsible for depigmentation, this second use according to the invention makes it possible to restore the function of this gene by introducing an agent that will activate the transcription of the said gene, for example by binding to its promoter region or by binding to a possible inhibitor that will as a result cease to inactivate the said gene.

A third use envisaged by the present invention in the field of therapy and cosmetics is the use of an agent modulating the function of the expression product of a DNA fragment corresponding at least in part to one of the 22 chromosomal regions of the invention. In the case of the therapeutic uses, the agent thus defined enters into the manufacture of a medicament. Preferably, the DNA fragment possesses at least 18 nucleotides.

In particular, such an agent according to the invention modulates the function of a transcript derived from a DNA fragment corresponding at least in part to the first chromosomal region of the invention. According to another case, an agent according to the invention modulates the function of a polypeptide derived from the translation of one of the transcripts mentioned.

Alternatively, the DNA fragment, the function of the expression product of which is modulated may correspond at least in part to the second chromosomal region of the invention, or the third, fourth, fifth, sixth, seventh, eighth, ninth, 10th, 11th, 12th, 13th, 14'h, 15th, 16t", 17t", 18th, 19", 20n, 21 St or 22nd chromosomal region of the invention.

Such an agent according to the invention may be capable of modulating the function of the expression product of an exogenous DNA fragment, a part of the sequence of which corresponds to one of the 22 chromosomal areas of the invention identified by the inventors or it my be capable of modulating the function of the expression product of an endogenous sequence included in one of these 22 chromosomal areas of the invention. Preferably, an agent being used for this third use according to the invention modulates not only the function of an expression product of an exogenous DNA fragment such as defined but also of the corresponding endogenous DNA fragment.

Modulating the function of a polypeptide may be carried out in different ways. In particular, it is possible to increase or decrease its activity, its yield, its specificity, its response to antibody, it is possible to modify its substrate for an enzyme, its level of conversion.

Agents according to the invention are preferably RNA molecules, called antisense RNA which hybridise with at least one transcript derived from a DNA fragment corresponding at least in part to the first chromosomal region of the invention or the second, the third, fourth, fifth, sixth, seventh, eighth, ninth, 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th, 21st or 22nd chromosomal region of the invention. Other agents fulfilling the same roles may be single-stranded DNA molecules or DNA-RNA hybrid molecules. The role of these agents according to the invention is preferably to promote, prevent, delay, accelerate or introduce errors in the translation of the said transcript.

Other preferred agents according to the invention belong to the class of the polypeptides. In particular, the invention relates to proteins capable of binding to the said transcript and of

thus modulating its translation. Such agents of the class of the proteins may be naturally occurring or synthetic (synthesised chemically or by a biotechnological route). In particular, they may be antibodies. As mentioned above, this modulation may result in the action of promoting, preventing, delaying, accelerating or introducing errors in the translation of the said transcript. In particular, the interaction between the polypeptide and the said transcript may constitute an obstacle to normal binding to the ribosomes.

Agents such as defined in the present invention may modulate the function of the protein encoded in a DNA fragment corresponding at least in part to the first chromosomal region of the invention. These agents are or are not protein in nature. An agent according to the invention may intervene at an early stage by preventing the correct folding of the protein. An agent according to the invention may also modify the function of the said protein by modifying its three-dimensional structure after folding. It may also be envisaged that this agent is an inhibitor of the protein, in particular a competitive inhibitor.

According to the other features of the invention, agents such as. defined in the present application may modulate the function of the protein encoded in a DNA fragment corresponding at least in part to the second chromosomal region of the invention, or to the third, fourth, fifth, sixth, seventh, eighth, ninth, 10", 11'", 12th, 13", 14th, 15'h, 16t", 17t", 18th, 19"\ 20"\ 21'or 22" chromosomat region of the invention identified by the inventors.

The agents which may be suitable in the context of the present invention are not limited to those previously mentioned.

In the context of this third use, the number of agents modifying the function of an expression product such as previously defined is not limited and is not necessarily restricted to only one.

However, in the context of this third use, the different agents that are used all have in common the capacity to modulate the function of expression products of DNA fragments the sequence of which belongs or corresponds to at least a part of the same chromosomal region of the invention. According to the first feature of the invention, this region is that of the human chromosome 1 identified by the inventors between the markers D1S2797 and D1S2868. According to the other features of the present invention, the chromosomal region in question is that identified by the inventors on the human chromosome 1 included between the markers D1S2842 and the telomer q, or that of the human chromosome 1 included between the markers D1S2667 and D1S199, or that of the human chromosome 2 included between the markers D2S149 and D2S392, or that of the human chromosome 2 included between the markers D2S347 and D2S142, or that of the human chromosome 3 included between the markers D3S3567 and D3S1277, or that of the human chromosome 3 included between the markers D3S1285 and D3S3653, or that of the human chromosome 4 included between the markers D4S1501 and D4S408, or that of the human chromosome 6 included between the markers D6S308 and D6S1581, or that of the human chromosome 7 included between the markers D7S657 and D7S530, or that of the human chromosome 7 included between the markers D7S1824 and D7S615, or that of the human chromosome 9 included between the markers D9S1677 and D9S1682, or that of the human chromosome 10 included between the markers D10S591 and D10S547, or that of the human chromosome 12 included between the markers D12S310 and D12S85, or that of the human chromosome 12 included between the markers D12S99 and D12S364, or that of the human chromosome 15 included between the markers D15S1040 and D15S641, or that of the human chromosome 15 included between the markers D15S978 and D15S153, or that of the human chromosome 16 included between the markers D16S503 and D16S516, or that of the human chromosome 16 included between the markers D16S3030 and D16S501, or that of the human chromosome 18 included between the markers D18S464 and D18S1102, or that of the human chromosome 19 included between the markers D19S216 and D19S221, or that of the human chromosome 20 included between the markers D20S107 and D20S100.

This third use according to the invention is preferably in the field of cosmetics.

This use may also make possible the manufacture of a medicament with a therapeutic action in the field of pigmentation.

According to a particular case envisaged, the third use described implies a genetic modification, whether it is induced by an agent modulating the function of the expression product of a DNA fragment such as described or not.

In the case in which the activation of a gene is responsible for depigmentation, this third use according to the invention makes it possible to abolish the function of this gene by introducing an antisense RNA that will block the translation of the said gene by preventing the passage from RNA to protein. Another preferred situation consists in choosing as agent an antibody capable of binding to the protein resulting from the translation of the said gene.

A fourth use envisaged by the present invention in the fields of therapy and cosmetics is the use of an expression product of a DNA fragment corresponding at least in part to one of the 22 chromosomal regions of the invention. In the case of the therapeutic uses, the agent thus defined enters into the manufacture of a medicament. Preferably, the DNA fragment possesses at least 18 nucleotides.

In particular, such an expression product is the RNA transcript derived from a DNA fragment corresponding at least in part to the first chromosomal region of the invention, or the second, third, fourth, fifth, sixth, seventh, eighth, ninth, 10'h, 11'h, 12th, 13th, 14'h, 15'h, 16th, 17'h, 18'h, 19th, 20th, 215t or 22nd chromosomal region of the invention, irrespective of the stage of maturation of the said transcript. In the case of splicing, the transcript may hence be smaller than the DNA fragment from which it is derived. Preferably, if the expression product is an RNA molecule, it comprises at least 18 nucleotides.

According to another preferred case, an expression product according to the invention is derived from the translation of one of the transcripts mentioned. Such an expression product may thus comprise less than 6 amino acids if the transcript from which it is derived has undergone splicing steps. Preferably, a peptide expression product contains at least 6 amino acids.

The expression product according to the invention does not necessarily result from the steps of transcription or translation of genomic DNA. In particular, an expression product used according to the invention may be an expression product derived from exogenous DNA at least a part of the sequence of which corresponds to all or part of one of the 22 chromosomal regions of the invention.

Also envisaged by the present invention is the use of a completely synthetic agent but which is similar to the expression product of an exogenous or endogenous DNA fragment corresponding at least in part to one of the 22 chromosomal regions of the invention.

Expression products such as used by the present invention are preferably RNA molecules, called antisense RNA, which hybridise with at least one transcript derived from a DNA fragment corresponding at least in part to the first chromosomal region of the invention, or the second, third, fourth, fifth, sixth, seventh, eighth, ninth, 10th, 11th, 12'h, 13'h, 14th, 15'h, 16'h, 17'h, 18tu, 19"', 20", 21s'or 22 chromosomal region of the invention. In particular, in order to form antisense RNA having as target a specific RNA, it is possible to envisage the use of RNA derived from the transcription of the same DNA sequence as the target but not of the leader strand but of its complementary sequence borne by the other strand. Thus are obtained RNA fragments complementary to the target fragments normally synthesised by the cell. The expected role of these expression products according to the invention is preferably to promote, prevent, delay, accelerate or introduce errors in the translation of the transcripts normally synthesised by the cell.

Other preferred expression products according to the invention belong to the class of the polypeptides. In particular, the invention relates to proteins capable of introducing a change in the functioning of the cell in which they act.

In the context of this use according to the invention, the number of expression products of a DNA fragment the sequence of which belongs or corresponds at least in part to one of the 22 chromosomal regions of the invention is not limited and may be greater than one.

However, in the context of this fourth use, the different products that are used all have in common the property of being expression products of DNA fragments the sequence of which belongs or corresponds to at least a part of the same chromosomal region of the invention.

According to the first feature of the invention, this region is that of the human chromosome 1

identified by the inventors between the markers D1S2797 and D1S2868. According to the other features of the present invention, the chromosomal region in question is that identified by the inventors on the human chromosome 1 included between the markers D1S2842 and the telomer q, or that of the human chromosome 1 included between the markers D1 S2667 and D1S199, or that of the human chromosome 2 included between the markers D2S149 and D2S392, or that of the human chromosome 2 included between the markers D2S347 and D2S142, or that of the human chromosome 3 included between the markers D3S3567 and D3S1277, or that of the human chromosome 3 included between the markers D3S1285 and D3S3653, or that of the human chromosome 4 included between the markers D4S1501 and D4S408, or that of the human chromosome 6 included between the markers D6S308 and D6S1581, or that of the human chromosome 7 included between the markers D7S657 and D7S530, or that of the human chromosome 7 included between the markers D7S1824 and D7S615, or that of the human chromosome 9 included between the markers D9S1677 and D9S1682, or that of the human chromosome 10 included between the markers D10S591 and D10S547, or that of the human chromosome 12 included between the markers D12S310 and D12S85, or that of the human chromosome 12 included between the markers D12S99 and D12S364, or that of the human chromosome 15 included between the markers D15S1040 and D15S641, or that of the human chromosome 15 included between the markers D15S978 and D15S153, or that of the human chromosome 16 included between the markers D16S503 and D16S516, or that of the human chromosome 16 included between the markers D16S3030 and D16S501, or that of the human chromosome 18 included between the markers D18S464 and D18S1102, or that of the human chromosome 19 included between the markers D19S216 and D19S221, or that of the human chromosome 20 included between the markers D20S107 and D20S100.

This fourth use according to the invention is preferably in the field of cosmetics.

This use may also make possible the manufacture of a medicament with a therapeutic action in the field of pigmentation.

According to a particular case envisaged, the fourth use described implies a genetic modification, whether it is induced by an expression product of a DNA fragment such as described or not.

In the case in which the activation of a gene is responsible for depigmentation, this fourth use according to the invention makes it possible to abolish the function of this gene by introducing an antisense RNA that will block the translation of the said gene by binding to the transcript synthesised by the cell.

In the case in which the inactivation of a gene is responsible for the depigmentation, this fourth use according to the invention makes it possible to restore the function of this gene by introducing into the cell either an RNA molecule permitting the synthesis of the protein encoded by the gene or the protein encoded by the gene.

For the four types of uses described previously in the context of the invention, the uses in cosmetics are preferably in the field of pigmentation.

For the four types of uses previously described, the product of the invention is capable of being incorporated in a cosmetic or pharmaceutical composition.

Such a composition comprises a quantity of products of the invention included between 0.001 and 10% by weight per volume in a pharmaceutical or cosmetically acceptable medium.

The composition may be administered by the oral route or applied to the skin (on any area of body skin) and/or the scalp or the hair.

By the oral route, the composition may contain the product (s) of the invention in solution in a nutrient liquid such as an aqueous or aqueous alcoholic solution, possibly flavoured. They may also be incorporated in a digestible solid excipient and are available for example in the form of granulates, pills, tablets or sugar-coated tablets. They may also be placed in solution in a nutrient liquid itself possibly packaged in digestible capsules.

Depending on the mode of administration, the composition can be made available in all of the galenical forms usually used, particularly in cosmetology.

A preferred composition of the invention is a cosmetic composition adapted to topical application to the scalp and/or the skin.

For a topical application, the usable composition may be in particular in the form of an aqueous, aqueous alcoholic or oily solution or a dispersion of the lotion or serum type, emulsions of liquid or semi-liquid consistency of the milk type, obtained by dispersion of a fat phase in an aqueous phase (O/W) or vie versa (W/O), or suspensions or emulsions of soft consistency of the cream or aqueous gel or anhydrous gel type, or also microcapsules or microparticles, or vesicular dispersions of the ionic and/or non-ionic type. Thus, it may be available in the form of an ointment, tincture, cream, pomade, powder, patch, impregnated swab, solution, emulsion or vesicular dispersion, lotion, gel, spray, suspension, shampoo, aerosol or foam. They may be anhydrous or aqueous. It may also consist of solid preparations constituting soaps or bars of soap.

These compositions are prepared according to the usual methods.

The composition may in particular be a composition for hair care and especially a shampoo, a hair-setting lotion, a treating lotion, a capping cream or gel, a composition of tinctures (in particular oxidation tinctures) possibly in the form of colour shampoos, restructuring lotions for the hair, mask.

When the invention consists of a use for cosmetic purposes, the composition will preferentially be a cream, a hair lotion, a shampoo or an after-shampoo.

The quantities of the different constituents of the usable compositions are those conventionally used in the fields under consideration.

When the composition is an emulsion, the proportion of the fat phase may vary from 5% to 80% by weight, and preferably from 5% to 50% by weight with respect to the total weight of the composition. The oils, the waxes, the emulsions and co-emulsions used in the composition in the form of an emulsion are chosen from among those conventionally used in the cosmetic field. The emulsifier and co-emulsifier are present in the composition in a proportion varying from 0.3% to 30% by weight, and preferably from 0.5 to 20% by weight with respect to the total weight of the composition. The emulsion may, in addition, contain lipid vesicles.

When the composition is a solution or an oily gel, the fat phase may represent more than 90% of the total weight of the composition.

In a variant, the composition will be such that the product (s) of the invention are encapsulated in a coating such as microspheres, nanospheres, oleosomes or nanocapsule, the coating will be chosen according to the chemical nature of the product of the invention.

As an example, it will be possible to prepare the microspheres according to the method described in the patent application EP 0 375 520.

The nanospheres can be made available in the form of an aqueous suspension and be prepared according to the methods described in the patent applications FR0015686 and FR0101438.

The oleosomes consist of an oil in water emulsion formed by oily droplets provided with a lamella liquid crystal coating dispersed in an aqueous phase (see the patent applications EP 0 641 557 and EP 0 705 593).

It will also be possible to encapsulate the products of the invention in nanocapsuies consisting of a lamella coating obtained starting from a siliconised surfactant (see the patent application EP 0 780 115), it will also be possible to prepare the nanocapsules from sulfonic polyesters dispersible in water (see patent application FR 0113337).

It will also be possible to complex the products of the invention to the surface of cationic oily droplets, whatever their size (see the patent applications EP 1 010 413, EP 1 010 414, EP1 010 415, EP 1 010 416, EP 1 013 338, EP 1 016 453, EP 1 018 363, EP 1 020 219, EP 1 025 898, EP 1 120 101, EP 1 120 102, EP 1 129 684, EP 1 160 005 AND EP 1 172 077).

The products of the invention may finally be complexed at the surface of nanocapsules or nanoparticles provided with a lamella coating (see EP 0 447 318 and EP O 557 489) and containing a cationic surfactant at the surface (see the previously cited references for the cationic surfactants).

In particular, a composition will be preferred such that the coating of the product (s) of the invention has a diameter less than or equal to 10 um.

In a known manner, the composition may also contain the usual adjuvants in the cosmetic field, such as hydrophilic or lipophilic gelling agents, hydrophilic or lipophilic additives, preservatives, antioxidants, solvents, perfumes, fillers, filters, odour and dye absorbents.

The quantities of these different adjuvants are those conventionally used in the cosmetic field, for example from 0.01% to 10% of the total weight of the composition. Depending on their nature, these adjuvants can be introduced in the fat phase, in the aqueous phase and/or in lipid microspheres.

As usable oils or waxes mention may be made of mineral oils (vaseline oil), vegetable oils (liquid fraction of karite butter, sunflower oil), animal oils (perhydrosqualene), synthetic oils (Purcellin oil), siliconised oils or waxes (cyclomethicone) and the fl uorinated oils (perfluoropolyethers), beeswax, carnauba wax or paraffin wax. To these oils may be added fatty alcohols and fatty acids (stearic acid).

As usable emulsifiers mention may be made for example of glycerol stearate, polysorbate 60 and the mixture of PEG-6/PEG-32/glycol stearate sold under the trade name Tefose@ 63 by the Gattefosse company.

As usable solvents mention may be made of the lower alcohols, in particular ethanol and isopropanol, propylene glycol.

As usable hydrophilic gelling agents mention my be made of the carboxyvinyl polymers (carbomer), the acrylic copolymers such as the acrylates/alkylacrylates, the polyacrylamides, the polysaccharides such as hydroxypropylcellulose, the natural gums and clays, and as lipophilic gelling agents, mention may be made of the modified clays like the bentones, the metal salts of fatty acids like aluminium stearate and hydrophobic silica, ethylcellulose, polyethylene.

The compositions may combine at least one product of the invention with other active agents. Of these active agents mention may be made as examples of: - agents modulating the differentiation and/or the proliferation and/or pigmentation of skin cells such as retinol and its esters, vitamin D and its derivatives, the estrogens such as estradiol, the cAMP modulators such as the POMC derivatives, adenosine or fc) rskoline and its derivatives, the prostaglandins and their derivatives, triiodotrionine and its derivatives; -plants extracts such as those of Iridaceae or soya, extracts likely or not to contain isoflavones ; - extracts of micro-organisms; - anti-free radical agents such as a-tocopherol or its esters, the superoxide dismutases or their mimetics, certain metal chelators or ascorbic acid and its esters; - the anti-seborrheic compounds such as certain sulfur-containing amino acids, 13-cis retinoic acid, cyproterone acetate; - the other agents for combating desquamative states of the scalp like zinc pyrithione, selenium disulfide, climbazole, undecylenic acid, ketoconazole, piroctone olamine (octopirox) or ciclopiroctone (ciclopirox) ; in particular, will be concerned active agents for stimulating the regrowth of hair and/or favouring the slowing down of hair loss, and more particular, non-limiting mention may be made of: - nicotinic acid esters, including in particular tocopherol nicotinate, benzyl nicotinate and the Ci-Ce alkyl nicotinates like methyl or hexyl nicotinates; - pyrimidine derivatives such as 2,4-diamino 6-piperidinopyrimidine 3-oxide or"Minoxidil" described in the patents US 4,139, 619 and US 4,596, 812; - the inhibitors of lipoxygenase or inducers of cyclo-oxidase that promote hair regrowth like those described by the applicant in the European patent application EP 0 648 488; - antibacterial agents such as the macrolides, the pyranosides and the tetracyclines, and in particular erythromycin; - the calcium antagonists like cinnarizine, nimodipine and nifedipine; - hormones such as estriol or analogues, or thyroxine and its salts ; - antiandrogenic agents, such as oxendolone, spironolactone and flutamide ; - steroidal or non-steroidal inhibitors of the 5-a-reductases such asthose described by the applicant in the European patent applications EP 0964 852 and EP 1 068 858 or also finasteride; - ATP-dependent potassium channel agonists such as cromakalim and nicorandil.

In another possible implementation, the present invention relates to processes for the diagnosis of a predisposition to premature canities in the individual.

In fact, premature canities is a phenotype which has been defined by the inventors as being characterised, among other things, by the appearance of the first white hair early in life, and preferably around the age of 18 years. As this phenotype is transmitted to the next generation, it may prove to be important for the individuals whose parent or close relative is affected, to determine whether they will or will not be subject to this ailment before the appearance of the symptoms. The diagnostic process according to the invention is perfectly suited to individuals under 18 years of age.

As it is very probable that environmental factors play a role in the"canities"phenotype as in that of"premature canities", what is entailed is an evaluation by means of the processes of the invention of the risks of developing such a phenotype, i. e. a predisposition to premature canities.

A process according to the invention for the determination of a predisposition to premature canities comprises a first step of selecting one or more markers which will be used in subsequent steps. By marker is meant a DNA sequence the different allelic variations of which are bearers of information. Such a marker may be a short sequence of a gene, the mutation of which is a source of the phenotype. It may also be a marker located physically on the chromosome in a region very close to a gene implicated in premature canities.

According to a first feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 1 included between the markers D1S2797 and D1S2868, i. e. to the first chromosomal area of the invention.

According to a second feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 1 included between the markers D1S2842 and the telomer q, i. e. to the second chromosomal area of the invention.

According to a third feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 1 included between the markers D1S2667 and D1S199, i. e. to the third chromosomal area of the invention.

According to a fourth feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 2 included between the markers D2S149 and D2S392, i. e. to the fourth chromosomal area of the invention.

According to a fifth feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 2 included between the markers D2S347 and D2S142, i. e. to the fifth chromosomal area of the invention.

According to a sixth feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, i. e. to the sixth chromosomal area of the invention.

According to a seventh feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 3 included between the markers D3S1285 and D3S3653, i. e. to the seventh chromosomal area of the invention.

According to a eighth feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 4 included between the markers D4S1501 and D4S408, i. e. to the eighth chromosomal area of the invention.

According to a ninth feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 6 included between the markers D6S308 and D6S1581, i. e. to the ninth chromosomal area of the invention.

According to a 10t feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 7 included between the markers D7S657 and D7S530, i. e. to the 10' chromosomal area of the invention.

According to a 11 feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 7 included between the markers D7S1824 and D7S615, i. e. to the 11th chromosomal area of the invention.

According to a 12""feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, i. e. to the 12th chromosomal area of the invention.

According to a 13"feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 10 included between the markers D10S591 and D10S547, i. e. to the 13""chromosomal area of the invention.

According to a 14th feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 12 included between the markers D12S310 and D12S85, i. e. to the 14"chromosomal area of the invention.

According to a 15""feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 12 included between the markers D12S99 and D12S364, i. e. to the 15"chromosomal area of the invention.

According to a 16th feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 15 included between the markers D15S1040 and D15S641, i. e. to the 16th chromosomal area of the invention.

According to a 17th feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 15 included between the markers D15S978 and D15S153, i. e. to the 17th chromosomal area of the invention.

According to a 18th feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 16 included between the markers D16S503 and D16S516, i. e. to the 18t chromosomal area of the invention.

According to a 19'"feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 16 included between the markers D16S3030 and D16S501, i. e. to the 19t chromosomal area of the invention.

According to a 20th feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 18 included between the markers D18S464 and D18S1102, i. e. to the 20"chromosomal area of the invention.

According to a 215'feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 19 included between the markers D19S216 and D19S221, i. e. to the 21S'chromosomal area of the invention.

According to a 22nd feature of a process of the invention, the marker (s) selected belong (s) to the region of the human chromosome 20 included between the markers D20S107 and D20S100, i. e. to the 22"d chromosomal area of the invention.

The next step in the implementation of a process according to the invention consists, for the selected marker (s), of determining the alleles present in a sample of genetic material derived from the individual who undergoes the diagnostic test. Two different alleles, borne by the two versions of the chromosome, may be identified.

The sample containing the genetic material may be blood, a single drop being sufficient for the implementation of a process according to the invention. Other samples of body fluids may be used in the context of the invention. It is also possible to consider using a few cells derived from the individual. The specialist skilled in the art will be able to determine which sample can be used in the context of this test, while minimising the inconvenience to the individual undergoing the test. It may be possible to couple this diagnostic test with other genetic tests.

The current techniques, well-known to the molecular biologist can be used to carry out the determination of the alleles of the marker (s) selected ; hybridisation tests are in particular very common in this type of step.

Various markers are potentially preferred in the context of the implementation of the process. of the invention. In particular, bi-allelic markers may prove to be particularly adequate if one allelic form reveals a predisposition to premature canities whereas, on the contrary, the other allelic form reflects the absence of such a predisposition. Other more common markers are polymorphic and may be found in at least two allelic forms and usually more than two.

Of the markers that can be selected at the first step of the process of the invention, particularly well known markers are the microsatellite markers. The properties of these markers have already been amply described in the context of the present invention. It is very important that the selection of the marker is based on the informative value of the polymorphism of the marker. A particularly favourable situation consists of selecting a marker certain allelic variants of which reflect a predisposition to premature canities whereas all of the other variants, on the contrary, reflect the absence of such a predisposition. In very many situations, the marker does not completely meet such a condition, i. e. for example certain alleles are preferentially but not exclusively present in the individuals predisposed to canities. In these situations, it may be very sensible to select several markers in order to establish as reliable a diagnostic test as possible.

When the markers selected are microsatellite markers, the different allelic variants correspond to the numbers of tandem repeats of the motif characterising the marker. A particularly advantageous situation to investigate when selecting a marker corresponds to the situation in which certain numbers of tandem repeats are characteristic of a predisposition to premature canities.

According to the first feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D1S2797, D1S2890, D1S230, D1S2841, D1S207 and D1S2868. These markers are microsatellite markers belonging to the first chromosomal area of the invention.

According to the second feature of a process of the invention, the marker (s) selected at the is'step may be chosen from among the following markers: D1S2842 and D1S836. These markers are microsatellite markers belonging to the 2nd chromosomal area of the invention.

According to the third feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D1S2667, D1S2697 and D1S199.

These markers are microsatellite markers belonging to the third chromosomal area of the invention.

According to the 4feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D2S149 and D2S392. These markers are microsatellite markers belonging to the 4'"chromosomal area of the invention.

According to the fifth feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D2S34, D2S112, D2S151 and D2S142. These markers are microsatellite markers belonging to the fifth chromosomal area. of the invention.

According to the sixth feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D3S3567 and D3S1277. These markers are microsatellite markers belonging to the 6t chromosomal area of the invention.

According to the seventh feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D3S1285, D3S1566 and D3S3653. These markers are microsatellite markers belonging to the seventh chromosomal area of the invention.

According to the eighth feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D4S1501 and D4S408. These markers are microsatellite markers belonging to the 8"chromosomal area of the invention.

According to the 9""feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D6S308, D6S441and D6S1581.

These markers are microsatellite markers belonging to the 9t chromosomal area of the invention.

According to the 10"feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D7S657, D7S515, D7S486 and D7S530. These markers are microsatellite markers belonging to the 10'"chromosomal area of the invention.

According to the 11 feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D7S1824 and D7S615. These markers are microsatellite markers belonging to the 11t chromosomal area of the invention.

According to the 12th feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D9S1677, D9S1776 and D9S1682.

These markers are microsatellite markers belonging to the 12t chromosomal area of the invention.

According to the 13"feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D10S591, D10S189 and D10S547.

These markers are microsatellite markers belonging to the 13t chromosomal area of the invention.

According to the 14"feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D12S310, D12S1617, D12S345 and D12S85. These markers are microsatellite markers belonging to the 14th chromosomal area of the invention.

According to the 15th feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D12S99, D12S336 and D12S364.

These markers are microsatellite markers belonging to the 15thchromosomal area of the invention.

According to the 16"feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D15S1040 and D15S641. These markers are microsatellite markers belonging to the 16th chromosomal area of the invention According to the 17th feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D15S978, D15S117 and D15S153.

These markers are microsatellite markers belonging to the 17th chromosomal area of the invention.

According to the 18"feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D16S503, D16S515 and D16S516.

These markers are microsatellite markers belonging to the 18thchromosomal area of the invention.

According to the 19th feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D16S3030 and D16S501. These markers are microsatellite markers belonging to the 19"chromosomal area of the invention.

According to the 20""feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D18S464, D18S531, D18S478 and D18S1102. These markers are microsatellite markers belonging to the 20t chromosomal area of the invention.

According to the 215t feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D19S216, D19S884 and D19S221.

These markers are microsatellite markers belonging to the 21"chromosomal area of the invention.

According to the 22nd feature of a process of the invention, the marker (s) selected at the first step may be chosen from among the following markers: D20S107, D20S119, D20S178 and D20S100. These markers are microsatellite markers belonging to the 22"d chromosomal area of the invention.

The processes of the invention are not limited to the two steps described and may contain other steps before or after the two steps mentioned.

In particular, a process of the invention may comprise the additional step of comparison of the allelic form of the marker (s) selected to the allelic form of this or those same marker (s) in other individuals. This additional comparative step may prove to be necessary in order to establish the diagnosis. In this case, it may be useful to make the comparison with the form of the marker (s) in individuals well-known to be affected by premature canities and possibly also with the form of the marker (s) in individuals well-known to be free from such a predisposition.

Given that premature canities is a probably multigenic ailment, thecauses of predisposition are many and it may be difficult to consider all of them exhaustively. On the other hand, within the same family certain members of which have suffered from premature.. canities, it is very probable that there is a single cause of the susceptibility. As a result, during the comparative step, mentioned as a possible third stage of the processes of the invention, a comparison particularly rich in information is the comparison of the alleles of the marker of the individual undergoing the test with the alleles of the same marker for the persons of his/her family whose phenotype is known. If several markers have been selected, this operation should preferably be repeated for all of the markers.

The present invention also relates to screening processes for molecules having a particular effect. In particular, the invention relates to an identification process for molecules capable of modulating the function of a polynucleotide fragment. According to the first feature of the invention, the polynucleotide fragment, the modulation of the function of which is desired, comprises at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 1 included between the markers D1S2797 and D1 S2868. According to the other features of the invention, the polynucleotide fragment, the modulation of the function of which is desired, comprises at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the second chromosomal region of the invention, or to the third, fourth, fifth, sixth, seventh, eighth, ninth, 10th, 11'", 12t", 13t", 14'h, 15'", 16'", 17'", 18'", 19'", 20'", 21"or 22 chromosoma) region of the invention.

The identification. process for molecules capable of modulating the function of any one of these fragments comprises a stage involving the placing of the test molecule in the presence

of the polynucleotide fragment. Another stage of the process is the detection of possible binding of this molecule to the polynucleotide fragment detected by a ligand detection technique.

The"second use according to the invention"is the use of an agent modulating the function of a DNA fragment corresponding at least in part to one of the chromosomal areas of the invention. The screening process makes it possible to identify such agents.

The different functions that a polynucleotide fragment can assume have already been made clear in the present application. In particular, these functions depend on the nature of the polynucleotide fragment, according to whether it is DNA or RNA, for example. A modulation of the function may correspond to a diminution of the capacity to be transcribed, or translated or to a change in the capacity to interact with other factors. As a function of the properties of the said fragment used, the specialist skilled in the art is capable of determining that parameter in which variation is easy to monitor.

The identification process of the invention is not limited to the stages previously described, other stages may be applied before or after.

The present invention also covers the molecules identified by the process previously described. In particular, the present invention covers the inhibitors of the functions of the polynucleotide fragments of the invention.

The present invention also relates to screening processes for molecules capable of modulating the function of the expression product of a polynucleotide fragment of the invention. According to the first feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 1 included between the markers D1S2797 and D1S2868. According to the second feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 1 included between the marker D1S2842 and the telomer q. According to the third feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 1 included between the markers D1S2667 and D1S199.

According to the fourth feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 2 included between the markers D2S149 and D2S392. According to the fifth feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 2 included between the markers D2S347 and D2S142. According to the sixth feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 3 included between the markers D3S3567 and D3S1277. According to the seventh feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 3 included between the markers D3S1285 and D3S3653. According to the eighth feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 4 included between the markers D4S1501 and D4S408. According to the ninth feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 6 included between the markers D6S308 and D6S1581. According to the 10'"feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 7 included between the markers D7S657 and D7S530. According to the 11th feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 7 included between the markers D7S1824 and D7S615. According to the 12th feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 9 included between the markers D9S1677 and D9S1682.

According to the 13t feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 10 included between the markers D10S591 and D10S547. According to the 14"feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 12 included between the markers D12S310 and D12S85. According to the 15' feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 12 included between the markers D12S99 and D12S364. According to the 16 in feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 15 included between the markers D15S1040 and D15S641.

According to the 17'"feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 15 included between the markers D15S978 and D15S153. According to the 18"feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 16 included between the markers D16S503 and D16S516. According to the 19t feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 16 included between the markers D16S3030 and D16S501. According to the 20th feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 18 included between the markers D18S464 and D18S1102. According to the 215t feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to all or part of the region of the human chromosome 19 included between the markers D19S216 and D19S221. According to the 22nd feature of the invention the expression product, the modulation of the function of which is desired, is that of a DNA fragment belonging and/or corresponding to ail or part of the region of the human chromosome 20 included between the markers D20S107 and D20S100. Preferably the DNA fragment comprises at least 18 nucleotides.

The identification process for molecules capable of modulating the function of the expression product of a DNA fragment such as described comprises a step in which the test molecule is placed in the presence of the expression product. Another step of the process is the detection of a variation of a parameter linked to the function of the said expression product, for example the detection of a possible binding of this molecule to the expression product detected by a ligand detection technique.

As mentioned previously in the application, by expression product of a DNA fragment is meant both the RNA molecules derived from the transcription of the fragment, at every stage of maturation, and the polypeptides derived from translation also at every stage of maturation. In the case of an RNA molecule, different stages of maturation are represented by the presence or absence of a cap or a polyadenylated tail, for example. By different stages of maturation of a polypeptide is meant, among other things, the polypeptides before and after folding, before and after cleavage of the various address signals, with and without glycosylation, with and without disulfide bridges.

As for the functions performed by the expression products of the DNA fragments, they are very numerous and they depend on the nature of the expression product in question.

Examples have already been given above in the present application.

The"third use according to the invention"is the use of an agent that modulates the function of the expression product of a DNA fragment. The screening process makes it possible to identify such agents. As regards what must be understood by the phrase"modulate the function of the expression product of a DNA fragment", examples have already been given to define the third use according to the invention.

Depending on the properties of the said expression product used, the specialist skilled in the art is capable of determining that parameter in which variation is easy to monitor.

The identification process of the invention is not limited to the steps previously described, other steps may be applied before or after.

The present invention also covers the molecules identified by the process previously described. In particular, the present invention covers the inhibitors of the functions of the expression products of the polynucleotide fragments of the invention.

The present invention also makes it possible to detect the genes implicated in the pigmentation of the skin, the hair and the phanera within the 22 chromosomal areas of the invention. A particular use envisaged by the present invention thus consists of using the microsatellite markers previously described within each of the chromosomal. regions of interest for the purpose of localising more specifically the genes implicated in pigmentation, and more particularly those implicated in the progressive or sudden interruption of the pigmentation of the skin or of the phanera.

In the context of these uses, according to the first feature of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the markers D1S2797, D1S2890, D1S230, D1S2841, D1S207 and D1S2868. These markers are microsatellite markers belonging to the first chromosomal area of the invention.

According to the second feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D1S2842 and D1S836.

According to the third feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D1S2667, D1S2697 and D1S199.

According to the fourth feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D2S149 and D2S392.

According to the fifth feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D2S347, D2S112, D2S151 and D2S142.

According to the sixth feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D3S3567 and D3S1277.

According to the seventh feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D3S1285, D3S1566 and D3S3653.

According to the eighth feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D4S1501 and D4S408.

According to the ninth feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D6S308, D6S441 and D6S1581.

According to the 10t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D7S657, D7S515, D7S486 and D7S530.

According to the 11t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D7S1824 and D7S615.

According to the 12th feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D9S1677, D9S1776 and D9S1682.

According to the 13t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D10S591, D10S189 and D10S547.

According to the 14t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D12S310, D12S1617, D12S345 and D12S85.

According to the 15t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D12S99, D12S336 and D12S364.

According to the 16t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D15S1040 and D15S641.

According to the 17t feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D15S978, D15S117 and D15S153.

According to the 18'"feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D16S503, D16S515 and D16S516.

According to the 19"feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D16S3030 and D16S501.

According to the 20th feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D18S464, D18S531, D18S478 and D18S1102.

According to the 215'feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D19S216, D19S884 and D19S221.

According to the 22nd feature of a process of the invention, the microsatellite markers which are used for the determination of the genes of interest are selected from the following markers: D20S107, D20S119, D20S178 and D20S100.

The present invention is based on the identification by the inventors of 22 chromosomal areas on the human chromosomes 1,2, 3,4, 6,7, 9,10, 12,15, 16, 18, 19 and 20, implicated in the phenomenon of pigmentation or depigmentation. This genetic basis has enabled them to envisage the uses in therapy and in cosmetics previously described, as well as the diagnostic processes previously illustrated.

But as already mentioned, the inventors suspect that many genes are implicated in the phenomenon of pigmentation, and in those linked to the regulation and cessation of this pigmentation. As a result, an important part of the present invention consists in combining the results obtained for the 22 chromosomal areas of the invention, in order to take the maximum advantage of the additional information.

In particular, a first combined use in the field of cosmetics and therapy preferably makes use of at least two polynucleotide fragments, the sequence of each of which corresponds, at least in part, to that of the region of the human chromosome 1 included between the markers D1S2797 and D1S2868, or to that of the region of the human chromosome 1 included between the marker D1S2842 and the telomer q, or to that of the region of the human chromosome 1 included between the markers D1S2667 and D1S199, or to that of the region of the human chromosome 2 included between the markers D2S149 and D2S392, or to that of the region of the human chromosome 2 included between the markers D2S347 and D2S142, or to that of the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, or to that of the region of the chromosome 3 included between the markers D3S1285 and D3S3653, or to that of the region of the human chromosome 4 included between the markers D4S1501 and D4S408, or to that of the region of the human chromosome 6 included between the markers D6S308 and D6S1581, or to that of the region of the human chromosome 7 included between the markers D7S657 and D7S530, or to that of the region of the human chromosome 7 included between the markers D7S1824 and D7S615, or to that of the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, or to that of the region of the human chromosome 10 included between the markers D10S591 and D10S547, or to that of the region of the human chromosome 12 included between the markers D12S310 and D12S85, or to that of the region of the human chromosome 12 included between the markers D12S99 and D12S364, or to that of the region of the human chromosome 15 included between the markers D15S1040 and D15S641, or to that of the region of the human chromosome 15 included between the markers D15S978 and D15S153, or to that of the region of the human chromosome 16 included between the markers D16S503 and D16S516, or to that of the region of the human chromosome 16 included between the markers D16S3030 and D16S501, or to that of the region of the human chromosome 18 included between the markers D18S464 and D18S1102, or to that of the region of the human chromosome 19 included between the markers D19S216 and D19S221, or to that of the region of the human chromosome 20 included between the markers D20S107 and D20S100.

In addition, in another patent application, filed by the same applicant, the inventors have also detected, by a similar method, other chromosomal areas on the human chromosomes 3,5, 6,9 and 11, also implicated in the phenomena of pigmentation and depigmentation. This genetic basis has enabled them to envisage uses in therapy and in cosmetics similar to those described previously, as well as diagnostic processes similar to those illustrated in the foregoing.

Preferably, use is thus made of two fragments or more, the sequence of at least one corresponding at least in part to one of the 22 chromosomal areas of the invention (for example the1 region of the invention, or the 2, 3rd, 4, 5, 6, 7, 8, 9, 10th, 11th, 12th, <BR> <BR> <BR> 13'h 14'h 15'", 16'", 17'", 18'", 19'", 20'", 21"or 22" region of the invention), the sequence of the other or others corresponding, at least in part, either to those of the 22 previously mentioned regions on the chromosomes 1,2, 3,4, 6,7, 9,10, 12,15, 16,18, 19 and 20, or to that of the human chromosome 6 included between the markers D6S1629 and D6S257, or to that of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), or to that of the human chromosome 3 included between the markers D3S1277 and D3S1285, or to that of the human chromosome 5 included between the markers D5S2115 and D5S422, or to that of the human chromosome 11 included between the markers D11 S898 and D11 S925.

A sequence of the human chromosome 6 included between the markers D6S1629 and D6S257 comprises preferably all or part of-one of the following genes: HLAG, Nit 007592. 445, Nit 007592. 446, NT_007592. 506, NT_007592. 507, NT_007592. 508, HSPA1B, G8, NEU1, NG22, BAT8, HLA-DMB, HLA-DMA, BRD2, HLA-DQA1, HLA-DQA2, NT007592. 588, GRM4, RNF23, FLJ22638, NT_007592. 459 and NT007592. 457.

A sequence of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q) preferably comprises all or part of one of the following genes: FREQ, NT_030046. 18, NT_030046. 17, GTF3C5, CEL, CELL, FS, ABO, BARHL1, DDX31, GTF3C4 and Q96MA6, and preferentially DDX31 and GTF3C4.

A sequence of the human chromosome 3 included between the markers D3S1277 and D3S1285 preferably comprises all or part of one of the following genes: Kit1042, CCK, CACNA1D, ARHGEF3 and AL133097.

A sequence of the human chromosome 5 included between the markers D5S2115 and D5S422 preferably comprises all or part of one of the following genes: KLHL3, HNRPAO, CDC25C, EGR1, C5orf6, C5orf7, LOC51308, ETF1, HSPA9B, PCDHA1 to PCDHA13, CSF1R, RPL7, PDGFRB, TCOF1, AL133039, CD74, RPS14, NDST1, G3BP, GLRA1, C5orf3, MFAP3, GALNT10 and FLJ11715.

A sequence of the human chromosome 11 included between the markers D11S898 and D11S925 preferably comprises all or part of one of the following genes: GUCY1A2, CUL5, ACAT1, NPAT, ATM, AF035326, AF035327, AF035328, BC029536, FLJ20535, DRD2, ENS303941, IGSF4, LOC51092, BC010946, TAGLN, PCSK7 and ENS300650.

Preferably, among the different polynucleotide fragments which are used at least two have sequences corresponding to two distinct chromosomes. It can also be envisaged that for one and the same chromosomal area of the invention, the different fragments which are used have different chemical natures, for example DNA for the first fragment and RNA for the second. It can also be envisaged that different fragments have a sequence corresponding to the same chromosomal area, but with slight variations permitted by the definition "homologous sequences", i. e. at the most one nucleotide different out of 10, and preferably 1 out of 100.

The fragments according to the invention contain at least 18 successive nucleotides, these 18 nucleotides forming the sequence which must correspond at least partially to one of the 22 chromosomal areas of the invention.

All of the preferred uses, the chemical nature of the fragments, their environment have already been explained in detail in the part describing the first use according to the invention.

When at least two polynucleotide fragments are used, these two fragments are preferably borne by distinct molecules. It can also be envisaged that these two fragments form part, for example, of one and the same vector. According to a preferred case, the different fragments are of the same chemical nature, for example DNA in the case of all the fragments.

For the uses in therapy, the polynucleotide fragments enter into the manufacture of a medicament.

A second combined use envisaged by the present invention, in the field of therapy and in that of cosmetics, is the use of a combination of at least two agents each modulating the function of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 1 region of the invention, of the 2nd 3rd 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12, 13'", 14th, 15, 16, 17th, 18'h, 19'h 20th 215t 22nd region of the invention.

A preferred use takes advantage of the results obtained on the chromosomes 3,5, 6,9 and 11. Thus use is advantageously made of two or more agents, at least one modulating the function of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 22 chromosomal regions of the invention (for example the15t region of the invention, or the 2nd, 3rd, 4th, 5th 6th 7th 8th 9th, 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20'h, 215t or 22nd region of the invention), the other agent (s) each modulating the function of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 22 chromosomal regions previously mentioned, or to that of the human chromosome 6 included between the markers D6S1629 and D6S257, or to that of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), or to that of the human chromosome 3 included between the markers D3S1277 and D3S1285, or to that of the human chromosome 5 included between the markers D5S2115 and D5S422, or to that of the human chromosome 11 included between the markers D11S898 and D11S925.

A sequence of the human chromosome 6 included between the markers D6S1629 and D6S257 preferably comprises all or part of one of the following genes: HLAG, NT_007592. 445, NT_007592. 446, NT_007592. 506, Nit 007592. 507, NT007592. 508, HSPA1B, G8, NEU1, NG22, BAT8, HLA-DMB, HLA-DMA, BRD2, HLA-DQA1, HLA-DQA2, NT_007592. 588, GRM4, RNF23, FLJ22638, NT_007592. 459 and NT_007592. 457.

A sequence of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q) preferably comprises all or part of one of the following genes: FREQ, NT_030046. 18, NT030046. 17, GTF3C5, CEL, CELL, FS, ABO, BARHL1, DDX31, GTF3C4 and Q96MA6, and preferentially DDX31 and GTF3C4.

A sequence of the human chromosome 3 included between the markers D3S1277 and D3S1285 preferably comprises all or part of one of the following genes: KIAA1042, CCK, CACNA1D, ARHGEF3 and AL133097.

A sequence of the human chromosome 5 included between the markers D5S2115 and D5S422 preferably comprises all or part of one of the following genes: KLHL3, HNRPAO, CDC25C, EGR1, C5orf6, C5orf7, LOC51308, ETF1, HSPA9B, PCDHA1 to PCDHA13, CSF1R, RPL7, PDGFRB, TCOF1, AL133039, CD74, RPS14, NDST1, G3BP, GLRA1, C5orf3, MFAP3, GALNT10 and FLJ11715.

A sequence of the human chromosome 11 included between the markers D11S898 and D11S925 preferably comprises all or part of one of the following genes: GUCY1A2, CUL5, ACAT1, NPAT, ATM, AF035326, AF035327, AF035328, BC029536, FLJ20535, DRD2, ENS303941, IGSF4, LOC51092, BC010946, TAGLN, PCSK7 and ENS300650.

Preferably, among the different agents which are used, at least two modulate the function of DNA fragments corresponding to two distinct chromosomes. It can also be envisaged that for one and the same chromosomal area of the invention, the different agents which are used modulate different functions of one and the same DNA fragment.

The DNA fragments, the function of which is modulated according to the invention, preferably contain at least 18 successive nucleotides, these 18 nucleotides forming the sequence that must correspond at least partially to one of the 22 chromosomal areas of the invention.

All of the preferred uses of such agents have already been explained in detail in the part describing the second use according to the invention.

For the uses in therapeutics, the agents enter into the manufacture of a medicament.

A third combined use envisaged by the present invention, in the field of therapy and in that of cosmetics is the use of a combination of at least two agents each modulating the function of the expression product of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the region of the human chromosome 1 included between the markers D1S2797 and D1S2868, and from those belonging and/or corresponding to all or part of the region of the human chromosome 1 included between the marker D1S2842 and the telomer q, and from those belonging and/or corresponding to all or part of the region of the human chromosome 1 included between the markers D1S2667 and D1S199, and from those belonging and/or corresponding to all or part of the region of the human chromosome 2 included between the markers D2S149 and D2S392, and from those belonging and/or corresponding to all or part of the region of the human chromosome 2 included between the markers D2S347 and D2S142, and from those belonging and/or corresponding to all or part of the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, and from those belonging and/or corresponding to all or part of the region of the chromosome 3 included between the markers D3S1285 and D3S3653, and from those belonging and/or corresponding to all or part of the region of the human chromosome 4

included between the markers D4S1501 and D4S408, and from those belonging and/or corresponding to all or part of the region of the human chromosome 6 included between the markers D6S308 and D6S1581, and from those belonging and/or corresponding to all or part of the region of the human chromosome 7 included between the markers D7S657 and D7S530, and from those belonging and/or corresponding to all or part of the region of the human chromosome 7 included between the markers D7S1824 and D7S615, and from those belonging and/or corresponding to all or part of the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, and from those belonging and/or corresponding to all or part of the region of the human chromosome 10 included between the markers D10S591 and D10S547, and from those belonging and/or corresponding to all or part of the region of the human chromosome 12 included between the markers D12S310 and D12S85, and from those belonging and/or corresponding to all or part of the region of the human chromosome 12 included between the markers D12S99 and D12S364, and from those belonging and/or corresponding to all or part of the region of the human chromosome 15 included between the markers D15S1040 and D15S641, and from those belonging and/or corresponding to all or part of the region of the human chromosome 15 included between the markers D15S978 and D15S153, and from those belonging and/or corresponding to all or part of the region of the human chromosome 16 included between the markers D16S503 and D16S516, and from those belonging and/or corresponding to all or part of the region of the human chromosome 16 included between the markers D16S3030 and D16S501, and from those belonging and/or corresponding to all or part of the region of the human chromosome 18 included between the markers D18S464 and D18S1102, and from those belonging and/or corresponding to all or part of the region of the human chromosome 19 included between the markers D19S216 and D19S221, and from those belonging and/or corresponding to all or part of the region of the human chromosome 20 included between the markers D20S107 and D20S100.

A preferred use takes advantage of the results obtained on the chromosomes 3,5, 6,9 and 11. Use is thus advantageously made of two or more agents, at least one modulating the function of the expression product of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 22 chromosomal regions of the invention (for example the1 region of the invention, or the 2nd 3rd, 4, 5th 6tu 7 8th 9th, 10th, 11th, 12th, 13t', 14, 15th 16t", 17'", 18'", 19'", 20'", 21"or 22 region of the invention), the other agent (s) each modulating the function of the expression product of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 22 regions previously mentioned or to that of the human chromosome 6 included between the markers D6S1629 and D6S257, or to that of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), or to that of the human chromosome 3 included between the markers D3S1277 and D3S1285, or to that of the human chromosome 5 included between the markers D5S2115 and D5S422, or to that of the human chromosome 11 included between the markers D11 S898 and D11 S925.

A sequence of the human chromosome 6 included between the markers D6S169 and D6S257 preferably comprises all or part of one of the following genes: HLAG, Nit 007592. 445, Nit 007592. 446, Nit 007592. 506, NT_007592. 507, NT_007592. 508, HSPA1B, G8, NEU1, NG22, BAT8, HLA-DMB, HLA-DMA, BRD2, HLA-DQA1, HLA-DQA2, NT_007592. 588, GRM4, RNF23, FLJ22638, Nit 007592. 459 and NT_007592. 457.

A sequence of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q) preferably comprises all or part of one of the following genes: FREQ, NT_030046. 18, NT_030046. 17, GTF3C5, CEL, CELL, FS, ABO, BARHL1, DDX31, GTF3C4 and Q96MA6, and preferentially DDX31 and GTF3C4.

A sequence of the human chromosome 3 included between the markers D3S1277 and D3S1285 preferably comprises all or part of one of the following genes: KIAA1042, CCK, CACNA1D, ARHGEF3 and AL133097.

A sequence of the human chromosome 5 included between the markers D5S2115 and D5S422 preferably comprises all or part of one of the following genes: KLHL3, HNRPAO, CDC25C, EGR1, C5orf6, C5orf7, LOC51308, ETF1, HSPA9B, PCDHA1 to PCDHA13, CSF1R, RPL7, PDGFRB, TCOF1, AL133039, CD74, RPS14, NDST1, G3BP, GLRA1, C5orf3, MFAP3, GALNT10 and FLJ11715.

A sequence of the human chromosome 11 included between the markers D11S898 and D11 S925 preferably comprises all or part of one of the following genes: GUCY1A2, CUL5, ACAT1, NPAT, ATM, AF035326, AF035327, AF035328, BC029536, FLJ20535, DRD2, ENS303941, IGSF4, LOC51092, BC010946, TAGLN, PCSK7 and ENS300650.

Preferably, among the different agents which are used, at least two modulate the function of the expression product of DNA fragments corresponding to two distinct chromosomes. It can also be envisaged that for one and the same chromosomal area of the invention, the different agents which are used modulate different functions of one and the same expression product of a DNA fragment, or modulate different expression products of a DNA fragment, for example the RNA at different stages of maturation, or the RNA derived from different splicing.

The DNA fragments, the function of the expression product of which is modulated according to the invention, preferably contain at least 18 successive nucleotides, these 18 nucleotides forming the sequence that must correspond at least partially to one of the 22 chromosomal areas of the invention.

All of the preferred uses of such agents have already been explained in detail in the part describing the third use according to the invention.

For the uses in therapeutics, the agents enter into the manufacture of a medicament.

A fourth combined use envisaged by the present invention, in the field of therapy and in that of cosmetics, is the use of a combination of at least two expression products of DNA fragments selected from the fragments belonging and/or corresponding to all or part of the 1 region of the invention, of the 2nd, 3rd 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th, 21st, 22nd region of the invention.

A preferred use takes advantage of the results obtained on the chromosomes 3,5, 6,9 and 11. Thus use is advantageously made of two or more expression products, at least one is the expression product of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 22 chromosomal regions of the invention (for example the1 region of the invention, or the 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, 13th, 14th, 15'h, 16th, 17'h, 18", 19", 20", 21"or 22 region of the invention), the other agent (s) each being the expression product of a DNA fragment selected from the fragments belonging and/or corresponding to all or part of the 22 chromosomal regions previously mentioned, or to that of the human chromosome 6 included between the markers D6S1629 and D6S257, or to that of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), or to that of the human chromosome 3 included between the markers D3S1277 and D3S1285, or to that of the human chromosome 5 included between the markers D5S2115 and D5S422, or to that of the human chromosome 11 included between the markers D11 S898 and D11 S925.

A sequence of the human chromosome 6 included between the markers D6S1629 and D6S257 preferably comprises all or part of one of the following genes: HLAG, NT_007592. 445, NT_007592. 446, NT_007592. 506, NT007592. 507, NT_007592. 508, HSPA1B, G8, NEU1, NG22, BAT8, HLA-DMB, HLA-DMA, BRD2, HLA-DQA1, HLA-DQA2, NT_007592. 588, GRM4, RNF23, FLJ22638, NT007592. 459 and NT_007592. 457.

A sequence of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q) preferably comprises all or part of one of the following genes: FREQ, NT_030046. 18, NT 030046. 17, GTF3C5, CEL, CELL, FS, ABO, BARHL1, DDX31, GTF3C4 and Q96MA6, and preferentially DDX31 and GTF3C4.

A sequence of the human chromosome 3 included between the markers D3S1277 and D3S1285 preferably comprises all or part of one of the following genes: KIAA1042, CCK, CACNA1D, ARHGEF3 and AL133097.

A sequence of the human chromosome 5 included between the markers D5S2115 and D5S422 preferably comprises all or part of one of the following genes: KLHL3, HNRPAO, CDC25C, EGR1, C5orf6, C5orf7, LOC51308, ETF1, HSPA9B, PCDHA1 to PCDHA13, CSF1R, RPL7, PDGFRB, TCOF1, AL133039, CD74, RPS14, NDST1, G3BP, GLRA1, C5orf3, MFAP3, GALNT10 and FLJ11715.

A sequence of the human chromosome 11 included between the markers D11S898 and D11S925 preferably comprises all or part of one of the following genes: GUCY1A2, CUL5, ACAT1, NPAT, ATM, AF035326, AF035327, AF035328, BC029536, FLJ20535, DRD2, ENS303941, IGSF4, LOC51092, BC010946, TAGLN, PCSK7 and ENS300650.

Preferably, among the different expression products that are used, at least two are derived from DNA fragments corresponding to two distinct chromosomes. It can also be envisaged that for one and the same chromosomal area of the invention, the different expression products that are used are derived from one and the same DNA fragment, they may for example be RNA at different stages of maturation or RNA derived from different splicing.

The same possibilities are offered in the case of the polypeptides derived from the translation of the RNA.

The DNA fragments, the expression products are used according to the invention, preferably contain at least 18 successive nucleotides, these 18 nucleotides forming the sequence that must correspond at least partially to one of the 22 chromosomal areas of the invention.

All of the preferred uses of such expression products have already been explained in detail in the part describing the fourth use according to the invention.

For the uses in therapeutics, the agents enter into the manufacture of a medicament.

In the case of the four types of combined uses described in the foregoing in the context of the invention, the uses in cosmetics are preferably in the field of pigmentation.

Among the many combinations envisaged by the present invention, a very useful combination comprises at least one polynucleotide fragment corresponding to all or part of the region of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q), and preferably included in the DDX31 or GTF3C4 gene for the first combined use.

For the second combined use, among the agents that are used preferably at least one of these agents modulates the function of a DNA fragment corresponding or belonging to the region of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q), and preferably included in the DDX31 or GTF3C4 gene.

For the third combined use, among the agents that are used preferably at least one of these agents modulates the function of the expression product of a DNA fragment corresponding or belonging to the region of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer q), and preferably included in the DDX31 or GTF3C4 gene.

For the fourth combined use, among the expression products that are used preferably at least one of these expression products is derived from a DNA fragment corresponding or

belonging to the region of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), and preferably included in the DDX31 or GTF3C4 gene.

In all of the combined uses described in the foregoing, in cosmetics or in therapy, use is made of several fragments or of several expression products of a fragment or of several agents modulating the function of fragments, or of several agents modulating the function of the expression product of fragments, where the fragment in question corresponds to all or part of one of the 22 chromosomal areas of the invention. Preferably, at least one of the fragments in question corresponds to the 15t region of the invention, or to the 2nid, 3, 4th. 5, 6"\ th th 11th 12th 13th 14th 15th 16th, 17th, 18, 19, 20, 21 or to the region of the invention.

In the case of the four types of combined use described in the foregoing, it will be possible to incorporate the combinations of the invention in a cosmetic or pharmaceutical composition such as described above.

In order to take advantage of the combination of these chromosomal areas, the present invention also relates to combination processes. The processes are used to determine a possible predisposition to premature canities.

A combination process according to the invention for the determination of a predisposition to premature canities comprises a first selection step of at least two markers that will be used in the following steps. The markers selected are chosen from the markers belonging to the region of the human chromosome 1 included between the markers D1S2797 and D1S2868, the markers belonging to the region of the human chromosome 1 included between the marker D1S2842 and the telomer q, the markers belonging to the region of the human chromosome 1 included between the markers D1S2667 and D1S199, the markers belonging to the region of the human chromosome 2 included between the markers D2S149 and D2S392, the markers belonging to the region of the human chromosome 2 included between the markers D2S347 and D2S142, the markers belonging to the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, the markers belonging to the region of the human chromosome 3 included between the markers D3S1285 and D3S3653, the markers belonging to the region of the human chromosome 4 included between the markers D4S1501 and D4S408, the markers belonging to the region of the human chromosome 6 included between the markers D6S308 and D6S1581, the markers belonging to the region of the human chromosome 7 included between the markers D7S657 and D7S530, the markers belonging to the region of the human chromosome 7 included between the markers D7S1824 and D7S615, the markers belonging to the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, the markers belonging to the region of the human chromosome 10 included between the

markers D10S591 and D10S547, the markers belonging to the region of the human chromosome 12 included between the markers D12S310 and D12S85, the markers belonging to the region of the human chromosome 12 included between the markers D12S99 and D12S364, the markers belonging to the region of the human chromosome 15 included between the markers D15S1040 and D15S641, the markers belonging to the region of the human chromosome 15 included between the markers D15S978 and D15S153, the markers belonging to the region of the human chromosome 16 included between the markers D16S503 and D16S516, the markers belonging to the region of the human chromosome 16 included between the markers D16S3030 and D16S501, the markers belonging to the region of the human chromosome 18 included between the markers D18S464 and D18S1102, the markers belonging to the region of the human chromosome 19 included between the markers D19S216 and D19S221, the markers belonging to the region of the human chromosome 20 included between the markers D20S107 and D20S100.

According to a variant of the process, at least one of the markers selected is chosen from the markers belonging to one of the 22 chromosomal regions of the invention (for example the1 region of the invention, or the 2, 3rd 4, 5 6tu 7th, 8th, 9th, 10th, 11th, 12th, 13th, 14th, 15'", 16t", 17'n, 18", 1 gn, 2tn, 215t or 22"d region of the invention), the other marker (s) belonging to the chromosomal regions previously mentioned, or to that of the human chromosome 6 included between the markers D6S1629 and D6S257, or to that of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), or to that of the human chromosome 3 included between the markers D3S1277 and D3S1285, or to that of the human chromosome 5 included between the markers D5S2115 and D5S422, or to that of the human chromosome 11 included between the markers D11S898 and D11S925.

Preferably, among the markers selected, at least two do not belong to the same chromosomal region of the invention. According to a particular case of the present invention, the markers, at least two in number, are chosen from the following list of markers: D6S1629, D6S1610, D6S1019, D6S1017, D6S1280, D6S1960, D6S257, D3S1277, D3S1768, D3S2409, D3S1289, D3S1766, D3S1300, D3S1285, D5S2115, D5S436, D5S410, D5S422, D9S290, D9S164, D9S158, D11S898, D11S908, D11S925, D1S2797, D1S2890, D1S230, <BR> <BR> <BR> <BR> D1S2841, D1S207, D1S2868, D1S2842, D1S836, D1S2667, D1S2697, D1S199, D2S149, D2S392, D2S34, D2S112, D2S151, D2S142, D3S3567, D3S1566, D3S3653, D4S1501, D4S408, D6S308, D6S441, D6S1581, D7S657, D7S515, D7S486, D7S530, D7S1824, D7S615, D9S1677, D9S1776, D9S1682, D10S591, D10S189, D10S547, D12S310, D12S1617, D12S345, D12S85, D12S99, D12S336, D12S364, D15S1040, D15S641, D15S978, D15S117, D15S153, D16S503, D16S515, D16S516, D16S3030, D16S501,

D18S464, D18S531, D18S478, D18S1102, D19S216, D19S884, D19S221, D20S107, D20S119, D20S178 and D20S100.

The next step in the implementation of a process according to the invention consists, in the case of the markers chosen, of determining the alleles present in a sample of the genetic material derived from the individual who undergoes the diagnostic test. Two different alleles, borne by the two versions of the chromosome, can be identified.

The modalities of the implementation of these processes have already been explained in the part devoted to the diagnostic processes.

The combined processes of the invention are not limited to the use of two markers, neither are they limited to the two steps described and may comprise other steps before or after the two steps mentioned.

In particular, a combined process of the invention may comprise the additional step of comparing the allelic form of the markers selected to the allelic form of those same markers in other individuals. This additional comparative step may prove to be necessary in order to establish the diagnosis. In this case, it may be useful to make the comparison with the form of the markers in individuals well-known to suffer from premature canities and possibly also with the form of the markers in individuals known to be free from such a predisposition.

As in the case of the diagnostic processes already mentioned in the present application, a particularly useful situation consists of comparing the alleles of the markers selected to the alleles of these same markers in other individuals of the same family as the individual to be diagnosed.

Finally, the present invention makes it possible to detect the genes implicated in the pigmentation of the skin, hair and phanera within the 22 chromosomal areas of the invention.

A particular use envisaged by the present invention thus consists in using a combination of microsatellite markers previously described within each of the chromosomal regions of interest for the purpose of localising more specifically the genes implicated in pigmentation, and more particularly those implicated in the progressive or sudden interruption of the pigmentation of the skin or phanera.

In the context of these uses according to the invention the microsatellite markers which are used to determine the genes of interest are chosen from the markers D1S2797, D1S2890, <BR> <BR> <BR> <BR> D1S230, D1S2841, D1S207, D1S2868, D1S2842, D1S836, D1S2667, D1S2697, D1S199, D2S149, D2S392, D2S34, D2S112, D2S151, D2S142, D3S3567, D3S1566, D3S3653, D4S1501, D4S408, D6S308, D6S441, D6S1581, D7S657, D7S515, D7S486, D7S530, D7S1824, D7S615, D9S1677, D9S1776, D9S1682, D10S591, D10S189, D10S547, D12S310, D12S1617, D12S345, D12S85, D12S99, D12S336, D12S364, D15S1040, D15S641, D15S978, D15S117, D15S153, D16S503, D16S515, D16S516, D16S3030, D16S501, D18S464, D18S531, D18S478, D18S1102, D19S216, D19S884, D19S221,

D20S107, D20S119, D20S178 and D20S100. The combination used comprises at least two markers and among the markers used at least two markers correspond to distinct chromosomal regions of the invention.

Finally, the present invention relates to a kit containing a combination of at least two polynucleotide fragments chosen from those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 1 included between the markers D1S2797 and D1S2868, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 1 included between the marker D1S2842 and the telomer q, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 1 included between the markers D1S2667 and D1S199, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 2 included between the markers D2S149 and D2S392, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 2 included between the markers D2S347 and D2S142, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 3 included between the markers D3S3567 and D3S1277, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the chromosome 3 included between the markers D3S1285 and D3S3653, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 4 included between the markers D4S1501 and D4S408, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 6 included between the markers D6S308 and D6S1581, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 7 included between the markers D7S657 and D7S530, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 7 included between the markers D7S1824 and D7S615, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 9 included between the markers D9S1677 and D9S1682, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 10 included between the markers D10S591 and D10S547, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 12 included between the markers D12S310 and D12S85, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to ail or part of the region of the human chromosome 12 included between the markers D12S99 and D12S364, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 15 included between the markers D15S1040 and D15S641, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 15 included between the markers D15S978 and D15S153, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 16 included between the markers D16S503 and D16S516, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 16 included between the markers D16S3030 and D16S501, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 18 included between the markers D18S464 and D18S1102, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 19 included between the markers D19S216 and D19S221, and those comprising at least 18 consecutive nucleotides the sequence of which corresponds to all or part of the region of the human chromosome 20 included between the markers D20S107 and D20S100.

According to a variant of the kit, the latter comprises two or more fragments, the sequence of at least one corresponding, at least in part, to one of the 22 chromosomal regions of the invention (for example the15t region of the invention, or the 2nd 3rd 4th 5th 6th 7th, 8th gth 10th, 11th, 12th, 13th, 14th, 15th, 16th, 17th, 18th, 19th, 20th, 21st or 22nd region of the invention), the sequence of the other or each of the others corresponding, at least in part, either to those previously mentioned or to that of the region of the human chromosome 6 included between the markers D6S1629 and D6S257, or to that of the region of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm), or to that of the region of the human chromosome 3 included between the markers D3S1277 and D3S1285, or to that of the human chromosome 5 included between the markers D5S2115 and D5S422, or to that of the human chromosome 11 included between the markers D11 S898 and D11 S925.

A sequence of the human chromosome 6 included between the markers D6S1629 and D6S257 preferably comprises all or part of one of the following genes: HLAG, Nit 007592. 445, NT_007592. 446, NT_007592. 506, NT_007592. 507, Nit 007592. 508, HSPA1B, G8, NEU1, NG22, BAT8, HLA-DMB, HLA-DMA, BRD2, HLA-DQA1, HLA-DQA2, Nit 007592. 588, GRM4, RNF23, FLJ22638, NT_007592. 459 and NT_007592. 457.

A sequence of the human chromosome 9 included between the marker D9S290 and the telomeric region (telomer of the long arm) preferably comprises all or part of one of the following genes: FREQ, NT-030046-18, NT-030046. 17, GTF3C5, CEL, CELL, FS, ABO, BARHL1, DDX31, GTF3C4 and Q96MA6, and preferentially DDX31 and GTF3C4.

A sequence of the human chromosome 3 included between the markers D3S1277 and D3S1285 preferably comprises all or part of one of the following genes: KIAA1042, CCK, CACNA1D, ARHGEF3 and AL133097.

A sequence of the human chromosome 5 included between the markers D5S2115 and D5S422 preferably comprises all or part of one of the following genes: KLHL3, HNRPAO, CDC25C, EGR1, C5orf6, C5orf7, LOC51308, ETF1, HSPA9B, PCDHA1 to PCDHA13, CSF1R, RPL7, PDGFRB, TCOF1, AL133039, CD74, RPS14, NDST1, G3BP, GLRA1, C5orf3, MFAP3, GALNT10 and FLJ11715.

A sequence of the human chromosome 11 included between the markers D11S898 and D1 1S925 preferably comprises all or part of one of the following genes: GUCY1A2, CUL5, ACAT1, NPAT, ATM, AF035326, AF035327, AF035328, BC029536, FLJ20535, DRD2, ENS303941, IGSF4, LOC51092, BC010946, TAGLN, PCSK7 and ENS300650.

Legends to the Figures Figure 1: Composition of the families analysed for linkage to the candidate-regions Figure 2: Chromosomal localisation of the candidate regions for PC and distribution of the markers Figure 3 : Graphic representation of the NPL scores obtained for the global genome multipoints non-parametric linkage analysis of the PC families for the 22 chromosomes and chromosome X Abscissae= position of the genetic map (0 = pter) Ordinate = NPL score Figure 3A: Chromosomes 1 and 2 Figure 3B : Chromosomes 3 and 4 Figure 3C: Chromosomes 5 and 6 Figure 3D: Chromosomes 7 and 8 Figure 3E: Chromosomes 9 and 10 Figure 3F: Chromosomes 11 and 12 Figure 3G: Chromosomes 13 and 14 Figure 3H: Chromosomes 15 and 16 Figure 31 : Chromosomes 17 and 18 Figure 3J: Chromosomes 19 and 20 Figure 3K: Chromosomes 21 and 22 Figure 3L: Chromosome X Figure 4: Schematic representation of the PC loci identified on the chromosomes 6, 9, 11, 5 and 3 according to the 2 periods of analysis.

The distance between markers is indicated in cM.

Figure 4A : Chromosome 6, locus6p21-p12 Figure 4B : Chromosome 9, locus 9q34 Figure 4C: Chromosome 11, locus 11q14-q22 Figure 4D : Chromosome 5, locus 5q31-q32 Figure 4E: Chromosome 3, locus 3p14. 1-p12. 3 Figure 5: Lod scores simulated for the 29 families selected.

From left to right, the columns display the mean Lod score, the standard deviation, the minimum Lod score, the maximum Lod score and the group (A-E) in which the family is placed according to its score.

Figure 6: Potential Lod scores per family as a function of the degree of genetic heterogeneity of PC Figure 7 : Detailed Lod scores per family as a function of the degree of genetic heterogeneity of the PC: new simulation after inclusion of the new families.

Figure 8: New simulation on the families finalised for the research of the candidate chromosomal regions. Potential Lod scores as a function of the degree of heterogeneity.

The results are expressed per family.

Figure 9: Probability (in %) of attaining or exceeding a Lod score of 1,2 or 3 for each degree of heterogeneity.

The results are expressed per family.

Figure10 : Comparison of the composition of the families between the candidate regions analysis and the global genome analysis.

Figure 11 : Potential Lod scores as a function of the degree of heterogeneity of the PC.

The results are expressed per family.

Figure 12: Probability (in %) of attaining or exceeding a Lod score of 1,2 or 3 for each degree of heterogeneity.

The results are expressed per family.

EXAMPLES EXAMPLE 1 Summary of the work performed In order to localise the gene (s) for premature canities (PC), a programme of segregation analysis (genetic linkage) was carried out on families in which this trait is transmitted over generations. At the end of a series of preselections on the basis of the statistical power of the sample and of the confirmation of the phenotypes, 12 families were selected to participate in a linkage study and the DNA was prepared from a sample of peripheral blood of each of the informative individuals (presenting and not presenting the trait). The study was performed according to 2 principal approaches, an analysis targeted on 9 candidate regions and a large global genome study on the 22 autosomal chromosomes and the X chromosome.

From the set of analyses performed by fixing or not fixing parameters for the transmission of the PC trait, several potential loci emerge on the chromosomes 1,2, 3, 4,6, 7,9, 10,12, 15, 16, 18,19 and 20 in addition to those previously identified on the chromosomes 6,9, 11,5 and 3. Twenty two loci show suggestive signs of linkage to PC.

This study, and in particular the disagreement between the scores obtained for the parametric/non-parametric analyses suggests that premature canities would not be caused by a small number of genes with a major effect, but would rather be regulated by a multifactorial system including the action of several genes of predisposition.

INTRODUCTION The hereditary character of premature canities (PC), or the appearance of white hair early in life, is a hypothesis put forward a long time ago, owing to the familial character of the hair turning prematurely white in certain people.

In order to explore canities from a genetic standpoint, a study of segregation of the DNA in families in whom canities appears very early in life was carried out. In order to guarantee the best chances of success for this pursuit of the genes, the composition of the sample for the study was the result of a rigorous protocol for the assignment of the phenotype and the selection of the families. The PC phenotype was assigned only to individuals who possessed some grey hair before they were 25 years old and half of whose head of hair was grey by the time they were 30 years old. The families were selected for the study on the basis of their statistical performance in the segregation analysis.

The subject of the study performed is described according to four principal periods: A-Period 1: Determination of the potential of the study. A first selection of the most informative families is carried out by a linkage analysis simulation.

B-Period 2: Medical confirmation of the phenotypes and collection of the blood samples from the preselected families. This verification campaign results in a new list of candidate families for the study. A new linkage simulation makes it possible to estimate the potential of the corrected sample.

C-Period 3: Genetic linkage analysis with the candidate chromosomal regions for PC.

First phase of the analysis of the DNAs for the chromosomal regions which might contain the genes for PC.

D-Period 4: Global genetic linkage analysis of PC on the whole human genome. Familial segregation analysis of the DNA of the 22 autosomal chromosomes and the X chromosome in order to detect the regions which are linked to the PC trait.

The results obtained at each period are presented in the form of tables and figures in a summary manner in recapitulative tables or in a more complete manner in the detail tables.

RESULTS A-Period 1 : Choice of families with the aid of linkage analysis simulation.

At the conclusion of an attempt to select families with premature canities according to the informative criteria for a gene localisation, 29 families were subjected to a genetic linkage analysis simulation. On the basis of the availability of all the individuals, it turned out that this project possessed a very encouraging potential for success because nineteen pedigrees (i. e.

255 individuals) were then selected. This conclusion is only valid if the phenotypes are confirmed and if the majority of the subjects agree to take part in the study. This selection includes seven very informative families who individually might attain or exceed a Lod score Z = 4.00 (i. e. more than the lower limit of significance of the Lod score which is Z=3. 00). In order to assemble a maximum chance of success, it was very important that the diagnosis of PC is assigned rigorously.

Depending on the soundness of the clinical evaluation, the result of this study makes it possible to describe the families which are then assembled for the genetic study.

1. Criteria for the assignment of the PC phenotype Twenty nine families out of 65 were selected on structural criteria (total number of individuals, affected and available) to be analysed by simulation.

During the simulation process: a) a software programme generates a series of replicates of the code file by assigning simulated genotypes. The file obtained for each family explores several allelic combinations (genotypes) in each of the individuals. b) a software programme then analyses each of the replicates in order to estimate the possible Lod scores (Z) of the genetic linkage analysis for each family. The results, in the form of minimum, mean and maximum Lod scores thus make it possible to evaluate the potential of each family in this type of study.

Obviously, these estimations only remain valid in the case in which each individual is assigned a correct phenotype. In the case of uncertainty, the phenotype must be specified as unknown; it is then not taken into account in the study and thus does not need to be retained. The Lod score diminishes (in variable proportions) each time that an individual is removed on account of uncertain phenotype.

The genealogical trees were designed with the aid of a pedigree management software programme which also constructs the coded files (preplink files) for the genetic linkage analysis. In addition to the codes indicating for each individual the family relationships, the sex, the phenotype as well as the genotype which will be increased by the simulation software programme SLINK, an availability code (cd) (Table 1) is assigned. It thus moderates, by a code from 0 to 3, the informative character of each individual in the study.

The phenotype of each individual was assigned according to the information appearing in the pedigrees and the descriptive tables of the Genormax report. However, for certain individuals, the phenotype was modified according to the criteria indicated in Table 2. The individuals, not present on the initial pedigrees (identified only by a number) were marked phenotypically unknown, and were considered to be unavailable (cd=3). a. Availability codes During the simulation, only the individuals were taken into account for whom (Table 1): - according to the Genormax study it will be possible to collect blood for the purpose of preparing DNA for the genetic studies (age, domicile in metropolitan France/ overseas/abroad, a priori consent); -the premature canities phenotype will have been clearly defined (Table 2).

Table 1: Definition of the availability codes Availability code (cd) DNA phenotype 0 unavailable known 1 available unknown 2 available known 3 unavailable unknown Table 2: Definition of the phenotypes < 25 years 25 years >25 years No white hair 0 0 Some white hair (qb) (less than 50%) 2 0 0

b. Assianment of the phenotvpe as a function of age In order to eliminate the risks of errors, the following criteria were defined for the assignment of the phenotype as a function of age in the individuals under 30 years old. However, at the final clinical examination, it is desirable for the definition of the phenotype to be more quantitative. c. Other parameters After examination of the variation of the maximum Lod score in the family Can65 (test 100, 200,300, 500 replications), the number of replications (generations of the allelic combinations) was finally fixed at 200.

The frequency of the trait was fixed at 1%. The number of possible alleles for the genotype is fixed at 6 with an equivalent frequency for each.

2. Results a-Classification of the families according to their scores Table 3 gives an indication of the potential of the GENORMAX families as a function of the maximum Lod score (Zmax) attained (groups A-E). Figure 5 reports the simulated Lod score for each family.

Table 3: Family statistics/maximum Lod score. The detailed results are presented in the table of Figure 5. Maximum Lod Score (LMx) Number of families Group Zmax > or = 4 7 A 3<Zmax<4 6 B 2_Zmaxc3 6 C 1 <Zmax<2 7 D Zmax<1 3 E The maximum Lod score can only be attained when a DNA marker is 100% informative in a family. Most often, even with the type of markers used (the most informative markers in the chromosome regions to be visited) the Lod score will not attain its maximum value.

In genetic linkage analysis, the Lod score must attain or exceed the value of 3 (result at 1000/1) to be significant. b-Effect of an incorrect diagnosis on the results of linkaqe analysis The effect of the assignment of an incorrect diagnosis was tested on the results of analysis (in the case of linkage at a locus) by a simulation on the family Can46 by varying the phenotype of 1,2 or 3 individuals (Table 4).

Table 4: Lod scores obtained for a series of distances of the marker from the locus of the trait (maximum Lod score in bold type).

1-according to the current diagnosis (maximum lod score) distance 0.0 0.01 0.05 0.1 0.2 0.3 0.4 Lod score 2.28 2.24 2.08 1.88 1. 44 0.95 0.43 a 2-3 individuals incorrectly diagnosed (A2, R10, R19) distance 0.0 0.01 0.05 0.1 0.2 0.3 0. 4 Lod score-3.89-1. 75-0.90-0. 50-0.14-0. 01 0.01 a 3-2 individuals incorrectly diagnosed (A2, R19) distance 0.0 0.01 0.05 0.1 0.2 0.3 0.4 Lod score-2.85-0. 75-0.05 0.22 0.36 0.30 0.17 a 4-1 individual incorrectly diagnosed (R19) distance 0.0 0.01 0. 05 0.1 0.2 0.3 0.4 Lod score 1.24 1.24 1.23 1.16 0.94 0.63 0.27 a 3. Discussion, conclusion and decisions This simulation study makes it possible to place the 29 preselected families in 5 groups according to the potential maximum Lod score. Although a linkage is significant once the Lod score value of Z=3.00 has been attained, the inventors have preferred to distinguish 2 groups when this criterion is confirmed because the maximum simulated Lod score is very rarely attained. Thus the probability that this is the true Lod score for families placed in the group B (3 zu Zmax< 4) is quite low.

The families of group A will be informative in a genetic linkage analysis for the localisation of the gene (s) for PC. For that, no uncertainty must remain as regards the phenotype. In the case of doubt, it is advisable to exclude individuals, even families from the study.

However, in some of these families, the high proportion of individuals affected/not affected (sometimes all of the children affected) must incite an extreme mistrust with regard to the genetic character of the trait being 100%. Of course, it is not excluded that in some families the PC gene has been transmitted simultaneously by the paternal and maternal lines of the first generation. In this case, the grandchildren would all be affected (Can28,43, 53....). In order to be able to consider these few families positively, it is highly desirable to verify this hypothesis.

The families of group B are themselves very valuable because they enable the sample to be enriched, even though individually they will be unable to attain a significant Lod score in most cases. As a group, they may however make it possible to consolidate the Lod score, especially if it turns out that the trait is genetically (slightly) heterogeneous.

The families of group C may also be used in studies of replications of the genetic linkage results.

The families of groups D and E (Zmax<2) are poorly informative for a genetic linkage analysis.

Subject to a sound clinical characterisation, it seems that the families of groups A, B and C are appropriate for a genetic linkage analysis study and that samples must be collected from them (individuals with cd=2). In fact, the analyses of genetic linkage performed on inadequately characterised samples are bound to fail or bound to give a"poor"result (locus inexact). Given that in such analyses some parameters may not be under total control (in particular the exactitude of the information concerning the genotypes), and that the genetic heterogeneity always makes the task more difficult (because it reduces the power of the analysis on the whole set of the families), it seems therefore essential to assemble right from the start all of the strong points which can be handled. In this first step, the inventors have therefore strongly recommended that the phenotype of each individual with an appropriate availability code (cd=2) be carefully verified before collection (phenotype confirmed, or exclusion of the sample/family).

B-Period 2 : Collection of the samples, confirmation of the phenotypes and new estimations of the potential of the study On the basis of the results of period 1, the 19 families (groups A, B and C) selected to form a bank from which the pedigrees for the genetic linkage analyses will be taken, were contacted for confirmation of the PC diagnosis and collection of series of affect and non- affected individuals.

This medical verification campaign of the phenotypes has made it possible to confirm a large number of the PC diagnoses, but not all as anticipated. The refusal of several key individuals (affected by PC) to participate in the project, the death of some as well as the reassessment of some of the phenotypes has led to a certain number of families of not being selected and reduced the informativity potential of several other families.

1-Reappraísal of the potential of the study after confirmation of the phenotypes In order to re-appraise the potential of the study after verification of the phenotypes, the inventors have simulated a linkage analysis covering the 8 families which were still capable of being informative. Table 5 presents the results obtained for all of the 8 families in 3 situations of genetic heterogeneity (0%, i. e. all the families linked to the same locus, 50% or only half of the families linked to the locus, 70% or only about a third of the families linked).

Table 5: Potential Lod scores as a function of the degree of genetic heterogeneity of PC.

The detailed results by family are presented in the table of Figure 6.

Degree of Heterogeneity Mean StdDev Minimum Maximum Max period 1 09 5.094620 1.679698 1.221207 8.835722 38.823 50% 1.619190 1.553049 0.000000 7. 409957- 70% 0.835383 1.022004 0.000000 5. 517145- 2-Conclusion In a constant effort to optimise the sample for the linkage analyses, 4 additional families were identified (Table 6; 2 families-can65B and can46B-are collateral lines of the families can65 and can46) and the phenotypes verified again.

Table 6: Final list of the families 1 c103974 2 F104512 3 CAN33 4 CAN35 5 CAN43 6 CAN46 7 CAN46B 8 Can53 9 CAN55 10 CAN62 11 CAN65 12 CAN65B After a new simulation (Table 7), it turns out that the general maximum Lod score of linking is hardly greater (Z=8.91) if the 12 families selected (phenotypes strictly defined) are linked to the same locus. The expected increase of the Lod score as a result of the contribution of new families is however reduced by the correction and the re-appraisal of the phenotypes.

Table 7: New simulation after collection of the new families The potential Lod scores are expressed as a function of the degree of genetic heterogeneity The results are presented in the table of Figure 7.

Degree of Heterogeneity Mean StdDev Minimun Maximum 0% 4.752321 1.748924 0.356854 8.914062 50% 1.535356 1.418022 0.000000 6.078132 70% 0.719737 0.978920 0.000000 5.282466 The power of the sample can also be observed from the point of view of the number of replications which attain or exceed the Lod scores Z=1.0, Z=2.0, Z=3.0 respectively and which gives an approximation of the chance of finding a significant linkage (Table 8).

Table 8: Probabilities (in %) of attaining or exceeding a Lod score of 1,2 or 3 for each degree of heterogeneity Degree of heterogeneity 0% 50% 70% Lod score 1.000 99.500 57.000 27.000 2.000 95.500 31.000 8.500 3.000 84.500 14.000 3.500 C-Period 3: Genetic linkage analysis of PC with the candidate regions 1-Hypothesis Regions on the human chromosomes are called candidate because they were"linked"to PC by the expedient of diseases or phenotypes with which the trait is associated (Table 9).

A genetic linkage analysis of these regions may make it possible to verify the candidate status of some of them.

Table 9: Covered chromosomal regions and microsatellite markers Chromosome Region #1 Region#2 Associated trait (s) Number of markers 1 1p21-p13. 3 Waardenburg type IIB 5 2 2q35-q36 Klein-Waardenburg ; type 1, 111 4 3 3p14. 1-p12. 3 Klein-Waardenburg, type IIA 7 4 4q12 Piebaldism 5 5 5p15. 2-p15. 3 Cri du chat 4 6 6p21 Biermer, Basedow, Thyroïditis, 13 Myasthenia 8 8p22-p12 8q Werner, Rothmund-Thomson 9 15 15q21 Griscelli syndrome 4 19 19p13. 2 Myotonia 4<BR> total 55 2-Final composition of the families In the interest of technical optimisation, a sample of 92 affected and unaffected individuals among the 12 families is selected (see Figure 1). This selection is made as a function of the potential informativity of each individual and confirmed by a new linkage simulation. The addition of several individuals leads to a slight increase in the potential Lod score (from 8.91 to 9.04, according to complete homogeneity, Table 10) and hence in the power of the sample (Table 11).

Table 10: New simulation on the families finalised for the research on the candidate chromosomal regions. Potential Lod scores as a function of the degree of genetic heterogeneity.

Degree of heterogeneity Mean StdDev Minimun Maximum 0% 4.367608 1.649267 0.564761 9.042465 50% 1.354325 1.359845 0.000000 6.610168 70% 0.666549 0.891330 0.000000 4.988076 90% 0.222622 0.378039 0.000000 2.528617 Table 11 : Probabilities (in %) of attaining or exceeding Lod scores 1,2 or 3 for each degree of heterogeneity Degree of heterogeneity 0% 50% 70% 90% Lod score 1.000 98. 000 48.500 21.500 4.000 2.000 94. 500 23.500 9.500 0.500 3.000 79. 000 12.000 3.000 0.000 3-Candidate chromosomal regions for PC The candidate chromosomal regions for PC and the distribution of the markers analysed are presented in Figure 2.

4-Linkage analyses Several types of linkage analyses were carried out in order to increase the probability of observing a linkage existing between a chromosomal region and PC.

For these analyses, the following two approaches were carried out: - 2-point (iterative analysis between the trait and the markers taken one by one); - multipoint (analysis for each chromosome according to a marker map placed as a function of their respective distances) 1. Analyses with defined parameters, parametric (PL): Mode of transmission (dominant), frequency of the trait (1%), equifrequency of the alleles of markers tested and penetrance (90% heterozygous mutant-100% homozygous mutants). Method 2-point and multipoint.

2. Independent analysis of the mode of transmission of the trait, non-parametric (NPL): Deviation analysis of the proportion of alleles shared in the case of each pair of individuals affected (in each family by identity by lineage) compared with random transmission. In the multipoint analysis, all the affected pairs (all-pairs, score Z-all=log10 of p-values, and p values) were considered. In the 2-point method, sibling pairs were studied (affected sib-pair, p-values).

5-Results The best results for each candidate region are presented in Table 12.

Table 12: Result of the linkage analysis of the candidate regions When only a position is indicated and not the name of a marker, that means that the position is intermediate between 2 markers. Global 2-oint multi oint Chromo-Marker/Marker/Marker/ some Region Lod position cM Lod position cM NPL position cM 1p21- 1 p13. 3 2 2q35-q36 3p14.1- 3 12.3 1.03 @ 0. 2 D3S1285/90 1,55 82 2, 58 D3S2409/70 4 4 12 1, 22 D4S2639/24 5p15. 2- 5 15.3 0, 59 D5S392/0 6 6p21 1. 12 @ 0. 1 D6S1017/54 1,28 58 3, 56 D6S1017/54 8p22- 8 p12/8q 0. 9 0. 2 D8S1179/136 1, 19 D8S1179/136 15 15q21 0, 97 D15S659/40 19 19p13. 2 1. 8 @0. 1 D19S714/36 0,77 D19S433/45 0,99 D19S714/36 Positive families 2-points multi oint Chromo-position en cM/position in cM some Region ID Lod marker Lod marker NPL marker 1 1p21-p13.3 2 2q35-q36 104512 1, 04 D2S427 1,04 D2S247 1, 41 D2S247 3 3p14.1-p12. 3 53 1,54 D3S1285 1, 61 D3S1285 1, 58 D3S1285 46 0,63 D3S2459 1, 09 26/D3S1766 2, 09 D3S2406 4 4q12 5 5p15. 2-p15. 3 6 6p21 35 1,67 D6S1 629 0, 93 40/D6S1629 8 8p22-p12/8 15 15q21 * (8 19 19p13. 2 families) 1p21-p13. 3 Waardenburg type IIB 2q35-q36 Klein-Waardenburg, type 1, III 3p14. 1-p12. 3 Klein-Waardenburg, type IIA 4q 12 Piebaldism 5p15. 2-p15. 3 Cri du chat 6p21 Biermer, Basedow, Thyroiditis, Myasthenia 8p22-p12/8q Werner, Rothmund-Thomson 15q21 Griscelli syndrome 19p13. 2 Myotonia 6-Discussion and conclusion This study distinguishes a predominant locus for predisposition to premature canities on the chromosome 6p21-p12 in the region of the HLA genes (in the region of D6S1017 ; maximum scores NPL=3. 52, p=0.000514, Hlod=2. 01). The linkage region (with a 99% degree of confidence, NPL>2.50) is located between the positions 41 and 67 on the map of the markers selected. The non-parametric analysis furnishes a series of significant values between the positions 47 cM ad 58 cM (between D6S1019 and D6S1280). The Lod score although of suggestive rank also supports the localisation of a relevant gene on the chromosome 6p.

Other PC loci are also strongly suggested on the chromosomes 3p14-p12 (towards the markers D3S2409 and D3S1766 ; multipoint : NPL=2.58 at position 12 and Hlod=1. 55 at position 24) and 19p13 (close to the marker D19S714 ; 2-points: Lod=1.80 at 0 =0. 106).

These results confirm the presumptions which bear on the association of a certain number of chromosomal loci with PC (HLA, Klein-Wardenburg syndrome, myotonia).

It should be noted that only 2 families (CAN35 in the case of chromosome 6, CAN53 in the case of chromosome 3) show a relatively high linkage. A clear-cut linkage with these candidate loci was not observed in the case of the other most informative families (families 103974, CAN46,104512, CAN55). The global analysis of the genome has made it possible to reveal other PC loci.

The result of the linkage on chromosome 6p21 in the region of the HLA is very encouraging if it is remembered that the literature furnishes few examples of non-parametric analyses so informative. It provides a promising starting point for the identification of the genes sensitive to premature canities, with the aid of polymorphism association strategies.

D-Period 4: Global genetic linkage analysis of PC with the genome.

1-Hypothesis The linkage analysis centered on the 9 candidate chromosomal regions has taken into account that the regions 6p21 and 3p12-p14 are very probably potential loci of PC. However, families have not shown a clear-cut linkage to chromosome 6p and to chromosome 3p. That can be explained by: 1. a genetic heterogeneity of PC (the 2 most informative families are not linked to 6P): one sole gene is not implicated ; 2. a lack of manifest power of certain families (shown by simulations).

The other regions analysed in the context of the candidate approach have not shown linkage to PC.

The global analysis of the genome then makes it possible to visit all the chromosomes (a global probing) in order to find additional regions hitherto not candidates and possibly a major locus which might control premature canities.

This extensive analysis also makes it possible to estimate the degree of genetic heterogeneity of PC.

2-Content of the families They are the same families as those who were studied in the candidate regions phase (period 3) but, however, with an adjustment of the content of some of them (see Table 13). Some poorly informative members were replaced by others more recently recruited or whose diagnosis was made later.

Table 13: Comparison of the number of individuals studied in each family between the candidate regions analysis and the global genome analysis (detailed composition of the families, table of Figure 10) Families Candidate Regions Global Genome A35 11 11 A46 12 12 A65 5 9 A53 8 9 B43 7 7 B55 7 7 C33 6 6 C62 6 6 A46B 6 7 A65B 6 6 103974 12 10 104512 6 6 Total individuals 92 96 In order to confirm the advantage of the change in the sample, a new simulation of linkage analysis was carried out for different situations of genetic heterogeneity (Table 14 and tables of the Figures 11A, 11B, 11C and 11D). The Lod scores expressed show a favourable change. Thus, considering the possible mean Lod score, it would be possible to obtain a significant result (Z 3.0) for a heterogeneity attaining 20% (i. e. 1/5 of the families not linked to the locus). In fact, this-result is very conservative and it would be possible to attain the significance with a markedly more heterogeneous sample (namely 50-70% with the use of microsatellite markers showing a mean heterozygosity of 0.7).

Table 14: Potential Lod scores as a function of the degree of genetic heterogeneity of PC.

The detailed results are presented in the tables of Figure 11.

Degree of heterogeneity Mean StdDev Minimun Maximum 0% 4.751841 1.749689 0.334792 9.338889 20% 3.115806 1. 866821 0.024841 8. 780452 50% 1.378378 1.467071 0. 000000 7.508479 70% 0.672997 0.904472 0. 000000 5. 226281 90% 0.242418 0.402384 0. 000000 2.722478 The power of the sample can also be observed from the point of view of the number of replications (of genotypes) which attain or exceed the Lod scores Z=1.0, Z=2.0, Z=3.0 respectively. The probability of finding a significant linkage (Table 15 and Figure 12) with 4/6 of the families linked to the same locus is 50%. This result is based on a mean Lod score which is conservative.

Table 15: Probabilities (in %) of attaining or exceeding a Lod score of 1,2 or 3 for each degree of heterogeneity The detailed results are presented in the tables of Figure 12.

Degree of heterogeneity 0% 20% 50% 70% 90% 1.000 99.000 87.500 47.000 23.000 5. 500 2.000 93.500 69.500 25.500 11.500 0.500 3.000 84.000 48.500 15.000 3.500 0.000 Hence the analyses may indicate significant linkages if the heterogeneity of the sample does not exceed 20% (i. e. only 1/5 of the families not being linked to a single major locus), but it is still possible to identify a linkage in the case in which half of the families are not linked to this locus.

3-DNA markers The DNA of 96 individuals belonging to the 12 families selected was genotyped for 400 polymorphic markers distributed on the 12 autosomal chromosomes and the X chromosome (Table 16) according to a mean inter-marker interval of 9.2 cM (density). They are microsatellites of the DNA, which are composed of tandem repeats of the dinucleotide type (CA) n of the Genethon collection (Evry, France).

The majority of the markers used for the global analysis are different from those which were used for period 3 (only 4 markers are identical: D2S338, D3S1285, D6S1610, D15S153).

The mean degree of heterozygosity observed is 0.70 and the mean size of the inter-marker interval is situated at 9.2 cM.

Table 16: Number of markers analysed on each chromosome during the genome wide-scan. Chromosome No. of markers Chromosome No. of markers 1 31 13 14 2 30 14 14 3 23 15 14 4 22 16 13 5 22 17 15 6 20 18 14 7 22 19 12 8 14 20 13 9 20 21 5 10 20 22 7 11 18 X 18 12 19 total 400 4-Linkage analyses For this global approach, the inventors carried out several types of analyses in order to optimise their performances for finding a linkage between a region of the genome and PC.

The parametric analysis, more efficient from the point of view of power, takes into account the mode of transmission of the trait and is the more suitable in the case of monogenic traits.

The non-parametric analysis which makes it possible to identify a linkage even if the supposed mode of transmission is erroneous is consequently sounder in the case of multigenic traits.

For each of these analyses, the inventors used the methods already mentioned, the 2-point method (iterative analysis between the trait and each marker) and the multipoint method (global analysis on each chromosome in accordance with a map of markers). a-Analvses with defined parameters. parametric (PL) Mode of transmission (dominant) Frequency of the trait (1 %) Allelic equi-frequencies of all of the markers Defined penetrances (90% heterozygous mutants-100% homozygous mutants), 2-point and multipoint methods The linkage probability scores are expressed as: - Lod score Z (homogeneous sample) - Lod score ZH (heterogeneous sample) and degree of heterogeneity a (proportion of families which are not linked to this locus). b-Indeeendent analvsisof themode of transmission ofthetrait, non-parametric (NPL) It is an analysis of the deviation of the proportion of alleles shared by pairs of individuals affected compared with a random transmission of the alleles (identity by lineage) The inventors considered all of the pairs of individuals affected for the multipoint analysis, and the sibling pairs for the 2-points analyses.

The linkage probability scores are expressed as - NPL or Z-all (log10 of p value) for the multipoint method on all of the pairs of individuals affected; -"p" value for the 2-point method on all of the sibling pairs affected.

5-Results Figure 3 presents the NPL scores obtained for the non-parametric linkage analysis on each chromosome a-detailed results Tables 17 (best results of the 2-point analyses) and 18 (best results of the multi-point analyses) present the best results obtained for each chromosome.

Table 17: Best results of the 2-point analyses PL NPL Localisation Chromo cM some Locus* Marker (distance-pter) Z (t) Theta Z (a, t) Theta Alpha Sibpair Homogeneity Heterogeneity 1 10 D1S2785 266,3 0,22 0,28 0,22 0, 28 31 D1S468 4,2 0,22 0,16 0,37 20 D1S207 113,7 0,000079 13 D1S2836 285, 8 0,002101 16 D1S2890 85,7 0,000044 26 D1S2697 37,1 0,006029 2 20 D2S2216 111,2 0,617 0,26 18 D2S162 20,0 0,918 0,1 0,5 17 D2S151 152,0 0,000569 16 D2S112 141,6 0,005267 3 4 D3S1285 91, 2 0,688 0,2 0,819 0,12 0,59 15 D3S1601 214,4 0,006153 4 15 D4S419 33,4 0,302 0,28 6 D4S405 56,9 0,636 0 0,26 21 D4S403 25,9 0,001857 5 6 D5S422 164,2 2,007 0,14 2,007 0, 14 1 23 D5S647 74,07 0,021524 6 10 D6S257 79,9 1,422 0,2 19 D6S460 89,7 1,458 0 0,47 18 D6S441 154,1 0,000012 7 19 D7S531 5,3 0,632 0, 2 20 D7S636 162, 3 0, 769 0 0, 22 0, 033191 PL NPL Localisation Chromo cM some Locus* Marker distance-ter Z (t) Theta Z (a, t) Theta Alpha Sibpair Homogeneity Heterogeneity 8 12 D8S284 143,8 0,449 0,28 0,449 0,28 15 D8S550 21,3 0, 006432 9 16 D9S158 161, 7 0, 423 0,24 0,904 0 0,37 9 D9S175 70,3 0,008336 10 11 D10S189 19,0 0,904 0,18 1,175 0 0,37 12 D10S537 91,1 0,002928 11 19 D11S908 108, 6 0,777 0,2 0, 846 0,06 0,6 4 21,5 0,203028 12 13 D12S85 61,3 0,159 0,28 0,159 0,28 1 2 D12S1617 44, 0 0,000242 9 D12S345 53,1 0,021214 8 D12S336 19,7 0,001657 13 13 D13S171 25,1 0,452 0, 24 0,639 0,1 0,48 4 D13S217 17,2 0,004614 14 7 D14S283 13,9 0,515 0,3 0,515 0,3 1 5 D14S276 56, 3 0,01455445 15 3 D15S117 51,2 1, 212 0,14 1,531 0 0,56 4 D15S127 86,8 0, 00982 16 4 D16S3091 111, 1 0,346437 0,26 0, 347522 0,26 0,94 0,00523082 17 8 D17S831 6,1 0,264529 0,3 0,283898 0,24 0,62 14 D17S928 126,5 0,00908423 18 2 D18S1102 62,8 0,411 0,26 8 D18S452 18,7 0,944 0 0,33 19 5 D19S414 54, 0 0,489059 0,26 0,489059 0,26 1 8 D19S884 26,4 0,00071 20 13 D20S178 66,2 0, 163 0,32 0,559 0 0,26 10 D20S119 61,8 0, 000015 7 D20S196 0,000393 21 2 D21S1252 35,4 0,079 0, 42 6 D21S263 27, 4 0,174 0 0,18 0, 371978 22 4 D22S420 4,1 0,035 0,44 0,035 0,44 1 6 D22S539 14,4 0,010405 X 16 DXS987 22, 2 0,5071 0,28 0,9491 0 0,31 11 DXS8043 94, 2 0, 0758 Table 18: Best results of the multi-point analysis PL NPL Chromo|Localisation cM Z | (a, ZH) Z-all | p-value information some (distance-pter) Homogeneity Heterogeneity 1 262-3, 08 (0. 3786, 0. 8628) 1, 76 0, 0452 0, 74 2 40-9, 03 (0. 0003,-0. 0004) 2, 64 0, 0066 0, 74 3 72-9, 34 (0. 1411, 0. 4780) 2, 62 0, 0070 0, 78 101 2, 16 4 190-9, 46 (0. 1656, 0. 4308) 2, 06 0, 0251 0, 69 5 146-7, 84 (0. 0959, 0. 0787) 1, 70 0, 0503 0, 75 168-3, 97 (0. 4022, 1. 1118) 0, 71 0, 2334 0, 62 6 71-4, 30 (0. 2905, 0. 8051) 3, 52 0, 0006. 0. 72* 67-1, 55 (0. 3462, 0. 8285) 3, 20 0, 0015 0. 55* 57-0, 70 (0. 4546, 0. 9496) 3, 59 0, 0005 0. 68** 61 0, 40 (0. 6166, 1. 4294) 3, 30 0, 0011 0. 62** 7 119-10, 13 (0. 0018,-0. 0009) 2, 07 0, 0246 0, 70 153-11, 20 (0. 3174, 1. 0866) 1, 18 0, 1223 0, 72 8 70-8, 37 (0. 0339, 0. 0039) 1, 32 0, 0989 0, 75 9 151-6, 35 (0. 3301, 0. 8357) 3, 37 0, 0009 0, 69 131 2, 13 10 166-7, 67 (0. 1789, 0. 6069) 1, 90 0, 0343 0, 70 11 106-6, 31 (0. 3441, 1. 5288) 2, 61 0, 0072 0, 72 12 20-14, 66 (0. 0003,-0. 0004) 1, 45 0, 0787 0, 72 13 27-13, 63 (0. 0000,-0. 0001) 1, 82 0, 0401 0, 74 14 99-11, 87 (0. 0000,-0. 0000) 1, 82 0, 0403 0, 67 15 34-10, 78 (0. 0001,-0. 0003) 2, 10 0, 0228 0, 72 16 101-8, 38 (0. 0004,-0. 0004) 2, 69 0, 0058 0, 72 22 2, 12 17 82-6, 69 (0. 2686, 0. 5776) 1, 55 0, 0660 0, 72 18 85-12, 60 (0. 0814, 0. 0641) 1, 44 0, 0809 0, 69 19 9-12, 08 (0. 0000,-0. 0001) 1, 43 0, 0816 0, 71 PL NPL Chromo Localisation cM Z (a, ZH) some distance-ter Z-all p-value information t P) Homogeneify Heterogeneity 20 0-7, 89 (0. 0001,-0. 0002) 1, 79 0, 0429 0, 68 21 36-6, 59 (0. 0001,-0. 0003) 0, 84 0, 1977 0, 56 22 47-8, 50 (0. 0000,-0. 0000) 1, 31 0, 0995 0, 67 X 79 1, 49 0, 0771 0, 74 b-results retained Table 19 presents the best results retained for each type of analysis (PL, PL) discussed below : Table 19: Best results retained for each type of analysis (PL, NPL) 2-point (2P) or Chromosome Positionlpter Score Multipoint (MP) Non-parametric npl >3. 0 Z-all 6 57 3,59 MP <BR> <BR> <BR> <BR> <BR> 9 151 3, 37 MP<BR> <BR> <BR> <BR> <BR> npl >2. 5 Z-all 2 40 2, 64 MP 3 72 2,62 MP 16 101 2,69 MP 11 106 2, 61 MP npl >2.0 Z-all 9 131. 00-2, 13 MP 3 72 2,12 MP 101 2,16 MP 16 22 2,12 MP 15 34 2,10 MP 7 119 2,07 MP 4 190 2, 06 MP p<1x10-4 p 20 61,8 0,000015 2P 18 52,9 0,000072 2P 6 154,1 0,000012 2P 1 85,7 0,000044 2P 113,7 0, 000079 2P p<1x10-3 p 2 152,0 0, 000569 2P 12 44,0 0,000242 2P 19 26, 4 0, 00071 2P Parametric Lod >2. 0 Lod 5 164, 2 2, 007 2P Lod >1. 5 Lod 11 106 1,5288 MP 15 51, 2 1, 531 2P Lod >1. 0 Lod 7 153 1,0866 MP 5 168 1, 1118 MP 6 61 1,4294 MP 6 89,7 1,458 2P 10 19, 0 1, 175 2P i In terms of PL: a-a Lod score (2P) ZH=2.007 was recorded on the long arm of chromosome 5 (position 164.2 cM starting from the upper telomer) i. e. in position 3/4 on the band 5q31-q32. b-intermediate Lod scores (1.5<ZH<2. 0) - chromosome 11q14-q22, position 106 (MP-ZH=1. 53) - chromosome 15q21, position 51 (2P-ZH=1.53) c-interesting Lod scores (1. 0<ZH<1,. 5) - chromosome 7q32-q33, position153 (MP-ZH=1. 08) - chromosome 5q31-q32, position 168 (MP-ZH=1.11) - chromosome 6p21-p12, position 61 (MP-ZH=1.43) - chromosome 6q13-q14, position 90 (2P-ZH=1.46) - chromosome 10p13-p14, position 19 (2P-ZH=1.17) ii In terms of NPL: Here the log10 scores for the study of deviation of allelic sharing, identity by lineage (IBD) were distinguished for all of the pairs affected (Z-all multi-point study scores) as well as the p values for the pairs of siblings affected (affected sib-pairs, 2-point study scores, p-values).

The best scores are presented according to their rank with respect to the limit of significance: - Z-all>3, 2. 5<Z-all<3, 2. 0<Z-all<2. 5 - p<10-5 and 10-5<p<10-4 a-Scores Z-all>3. 0 The best score is attained on chromosome 6p21-p12, when the inventors use the combination of candidate region + global genome markers with a value Z-all=3. 59 at position 57 (between D6S1019 and D6S1017). This score is 4 cM more proximal than the Lod score MP-ZH=1.43, position 61. When only the global genome markers are used, the score reaches a maximum at a Z-all=3. 52 at position 71 (between the markers D6S1610 and D6S257). However, the precision of the locus is probably affected by the great distance between these 2 markers of the global genome battery which is considerably greater than the mean interval observed (26.11 cM).

The second best score is attained on chromosome 9q31-q32, position 151 (Z-all=3. 37) b-Scores 2. 5<Z-all<3. 0 - chromosome 2p21-p22, position 40 (Z-all=2. 64) - chromosome 3p14-p13, position 72 (Z-all=2. 62) - chromosome 16q22-q23, position 101 (Z-all=2. 69) - chromosome11q21-q22, position 106 (Z-all=2. 61) c-Scores 2. 0<Z-all<2. 5 - chromosome 16p13. 1-p12, position 22 (Z-all=2. 12) - chromosome 9q31-q32, position 131 (Z-all=2. 13) - chromosome 3q21, position 101 (Z-all=2. 15) - chromosome 15q13-q15, position 34 (Z-all=2. 1) - chromosome 7q22-q31. 1, position 119 (Z-all= 2.07) - chromosome 4q31-q32, position 190 (Z-all=2. 06) as well as the p-values <10-5 et 10-4 d. p<1x10-4 -chromosome 1p21-p13. 3, position 113.7 (p=0.000079) - chromosome 20q11. 2-q12, position 61.8 (p=0. 000015) - chromosome 18q11. 2-q12. 2, position 52.9 (p=0.000072) - chromosome 6q31. 3-q33, position 154 (p=0.000012) e. 10-4<p<10-3 - chromosome 2q11, position 152 (p=0.00057) - chromosome 12p11-q12, position 44 (p=0.00024) - chromosome 19p13. 1-p13. 2, position 26.4 (p=0.00071) iii The loci which are identified simultaneously by PL and NPL: PL NPL 6p21-p12, position 57-61 1. 42 3. 59 11 q 14-q22, position 106 1. 52 2. 6 6-Discussion and conclusion The 2 scores, either significant or at the limit of significance depending on whether the trait is considered as being monogenic or multifactorial (Lander and Krugliak 1995), were observed for the chromosomes 6p21-p12 (NPL MP Z-all=3. 59) and 9q31-q32 (NPL MP Z-all=3. 37).

Of these 2 loci, the more robust is that of 6p21-p12 which is reinforced by a MP-PL Lod score, which although average, reaches a maximum at ZH=1.42.

Another locus also appears to be quite interesting, it is located on chromosome 11q14-q22 because the PL and NPL scores reach a maximum at the same position 106 (Z-all 2.61, PL 1.52). The NPL score is moreover within the range of suggestivity in a case of monogenism or in a case of multigenism (suggestivity: monogenism 2<Z-all<3 ; multigenism 2.2<Z- all<3. 6).

Finally, the 5q31-q32 locus with the best PL Lod score (2P) (ZH=2.00) is also situated within the suggestivity values (in monogenism).

A series of p values must be added for the analyses of siblings affected which are also within the suggestivity range (chromosomes 6q31. 3-q33, 20q11. 2-Q12, 18q11. 2-q12. 2 and 1p21- p13. 3). They are loci to be considered too.

E-Discussion and general conclusion At the conclusion of the different periods of analyses (candidate regions and global genome) several chromosomal regions are identified or suggested.

1-Simultaneously by the candidate regionslglobal genome analyses The candidate regions/global genome analyses are based on batteries of different markers (only 4 markers in common). The inventors have thus paid particular attention to the level of reproducibility of the positive results between these two analyses.

Comparing the results emerging from the candidate regions/global genome approach (table 20: candidate regions/global genome comparison) two consensus regions stand out but with a very marked preference for chromosome 6: - chromosome 6p21-p12 - chromosome 3p14. 1-p12. 3 Table 20: Comparison of the best scores obtained for the candidate regions and global genome analysis CANDIDATE REGIONS 2-point multipoint position position position Region Lod cM Lod cM NPL cM 3p14. 1-p12. 3 1,03 90 1,55 82 2, 58 70 4q 12 1,22 24 5p15. 2-p15. 3 0,59 0 6p21 1,12 54 1,28 58 3,56 54 8q32-q33 0, 9 136 1,19 136 15q21 0,97 40 19p13. 2 1,8 36 0, 77 D19S433/45 0,99 36 GLOBAL GENOME 2-point multipoint position position position Region Lod cM Lod cM NPL cM 3p14. 1-p12. 3 0,819 91,2 0,794 83 2,61 72 4q 12 1,69 29 4q31-q32 0,636 56,9 2,06 190 5p15. 2-p15. 3 1,11 0 5q23-q31 1,18 168 1,7 146 5q31-q32 2,01 164 6p21 1,458 89,7 1,429 61 3,59 57 8q32-q33 0,449 143, 8 8q12-q13 1,32 70 15q21 1,53 51,2 2,1 34 19p13. 2 1, 42 51 19p13. 3 1, 43 9 2-Simultaneously by the parametric and non-parametric analyses a Candidate relions The region 6p21-p12 is a candidate region for the suspected role of the major histocompatibility genes (HLA, MHC) in premature canities. This study of genetic localisation thus confirms in a quite robust manner that this region of chromosome 6 contains a gene (or several genes) having a role in the pathophysiology of PC.

The non-parametric methods, although they make it possible to identify a locus in a robust manner in the case of an uncertainty of the genetic model of the trait studied, do not on the other hand lead to an exact localisation. In that case it is more necessary to consider a region between two extreme points and possibly reduce this region with the aid of the results of the parametric analyses if they are informative.

The chromosome 3p provides scores that are situated in an area suggestive of linkage.

Although these results do not confirm the role of the region 3p14. 1-p12. 3 in PC, they nonetheless constitute a potential locus not to be neglected. b Global qenome This comparison again leads to the retention of the chromosome 6p21-p12, although however the parametric score is situated in neither the significant nor the suggestive area.

The second locus is 11q14-q22 with a suggestive NPL score and a PL score which is located among the best obtained in this study (2nd rank, ZH=1.52). This region did not appear in the candidate regions linkage analysis programme.

3-Validity of the different loci In conclusion, it is the region 6p21-p12 (see Figure 4A) which has received the best consensus for a genetic linkage to the PC trait. The inconsistency between parametric and non-parametric analyses creates some uncertainties as regards the importance of the role of this or those gene (s) in the pathophysiology of canities.

The second locus is on the chromosome 9q31-q32 with an almost significant NPL score (Z- all=3. 37).

Other regions, previously mentioned, present an interest which, however, remains unconfirmed. Some of them appear in the ranks of the analyses that can be envisaged (11q14-q22, 5q31-q32, 3p14. 1-p12. 3). a Chromosome 6n21-p12 : The 2 analyses (periods 3 and 4) lead to the same conclusion (Figure 4A). The limits of the region designated by the linkage analysis are located at position 41 (upper limit, Z-all=2. 02) and position 95 (lower limit, Z-all=2. 09), i. e. 54cM. It is possible to reduce this region to a length of 15cM by considering the limits 65cM and 80cM (between D6S1610 and D6S257 respectively ; analysis 20 markers) or 50 cM and 73 cM (between D6S1629 and D6S1280 respectively ; analysis 33 markers).

The region identified contains the genes of the major histocompatibility complex (MHC, HLA). However, it cannot be excluded that a gene independent of the HLA may be implicated in the control or susceptibility of the PC trait. b Chromosome 9a34 The inventors place the proximal limit of this region (which was not a candidate) starting from the position which obtains a score Z-all=2. 5 on the marker D9S290; the distal limit being placed on the telomer of the long arm of chromosome 9 (towards the marker D9S158). This region extends over a length of 10cM (Figure 4B). c Chromosome 11q14-q ? 2 The inventors identify a region between the positions 100 and 115 (between D11S898 and D11 S925) (Figure 4C). d Chromosome 5a31-e32 This region obtains the best PL and 2-point result of those analyses which are located at a recombination distance (theta) 0.14 (about 14 cM) from the marker D5S422. By a displacement of this distance from D5S422 towards the top of the map (position 149), the neighbourhood of the locus is attained which produces the best multi-point NPL score of chromosome 5 (Z-all=1. 70, towards marker D5S436). A certain consensus appears also for this locus (Figure 4D). e Chromosome 3p14. 1-P12. 3 It is a region of almost 30 cM between the positions 60 and 87 (between D3S1277 and D3S1285). This region produces a consensus between the candidate regions and global genome analyses (Figure 4E).

EXAMPLE 2 Examples of compositions - hair lotion DNA fragment derived from the chromosomal area included between the markers D6S1629 and D6S257 0.5 g Propylene glycol 20 g 95'Ethanol 30 g Water qsp 100 g This lotion is applied daily to the areas to be treated and preferably to all of the scalp hair for at least 10 days and preferentially 1 to 2 months.

A diminution of the appearance of white or grey hair and a repigmentation of the grey hair is then observed.

- treating shampoo DNA fragment derived from the chromosomal area included between the marker D9S290 and the telomer of the long arm 1.5 g Polyglyceryl 3-hydroxylarylether 26 g Hydroxy propyl cellulose sold under the trade name of Klucell G by the Hercules company 2 g Preservatives qps 95'Ethanol 50 g Water qsp 100 g This shampoo is used each time the hair is washed and applied for about 1 minute.

Prolonged use for about 2 months leads to progressive repigmentation of the grey hair.

This shampoo may also be used as a preventive measure in order to delay the hair becoming white.

- treating gel DNA fragment derived from the chromosomal area included between the markers D6S1629 and D6S257 0.75 g Essential eucalyptus oils 1 g Econozole 0.2 g Lauryl polyglyceryl 6 cetearyl glycoether 1.9 g Preservatives qsp Carbopol934P sold by the BF Goodrich Corporation 0.3 g Neutralisation agent qs pH 7 Water qsp 100 g This gel is applied to the areas to be treated twice a day (morning and evening) followed by a massage. After three months'application, repigmentation of the hair in the treated area is observed.

Bibliographic references E. Lander and L. Kruglyak. Genetic dissection of complex traits: guidelines for interpreting and reporting results [see comments]. Nat. Genet. 11 (3): 241-247,1995.