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 Printable version |
Genotype-phenotype correlations in Y chromosome long arm deletions |
Médecine Thérapeutique / médecine de la reproduction. Volume 9, Number 5, 303-10, novembre-décembre 2007, Revue
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 Résumé
Article gratuit
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Author(s) : Sandra Chantot-Bastaraud, Célia Ravel, Ken Mc Elreavey, Jean-Pierre Siffroi |
Summary : The Y chromosome has two major roles in mammals which are sex determination in fetus and male reproduction in adults. Its sequencing in 2003 has revealed a unique structure of the long arm which contains large blocks of amplified sequences organized in palindromes and named amplicons. Recombinations between homologous sequences explain the occurrence of molecular deletions found in some infertile patients, leading to the loss of either AZFa, b or c regions. The two formers are known to be associated with azoospermia by Sertoli cell only syndrome or meiotic blockage, leading always to negative testicular biopsies, while the third one may be compatible with some degrees of spermatogenesis authorizing an ICSI in many cases. Recent data have pointed out the existence of partial deletions in AZFc, the clinical significance of which remains to be established. The most frequent of these partial deletions, the gr/gr deletion, is either considered as a polymorphism by some authors or as a predisposing factor to infertility by other. The extreme variability of Y chromosome structure among humans implies that genotype-phenotype correlations must now be established in very large cohorts of patients and normospermic controls of known geographic origins. |
Keywords : Y chromosome, partial deletion, infertility, spermatogenesis |
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