Reproductive genetics. Molecular and cytogenetic characterization of an azoospermic male with a de-novo Y;14 translocation and alternate centromere inactivation

• Published in: Human reproduction (Oxford) Vol. 17; no. 3; p. 564
• Main Authors: Buonadonna, A L, Cariola, F, Caroppo, E, A.Di Carlo, Fiorente, P, Valenzano, M C, D'Amato, G, Gentile, M
• Format: Journal Article
• Language: English
• Published: Oxford Oxford Publishing Limited (England) 01.03.2002
• ISSN: 0268-1161; 1460-2350

BACKGROUND: Y-autosome (Y/A) translocations have been reported in association with male infertility. Different hypotheses have been made as to correlations between Y/A translocations and spermatogenetic disturbances. We describe an azoospermic patient with a de-novo Y;14 translocation: 45,X,dic(Y;14)(q12;p11). METHODS AND RESULTS: Cytogenetic, fluorescent in-situ hybridization (FISH) and molecular studies have been performed. A 14/22 (D14Z1/D22Z1) centromere and a Y centromere (DYZ1) probe both showed a signal on the translocation chromosome, confirming its dicentricity. Each copy of the translocation chromosome had only one primary constriction, with inactivation of the Y centromere in most (90%) of the cells. The 14 centromere was inactive in the remaining cells (10%). FISH and molecular deletion mapping analysis allowed acute assignment of the Yq breakpoint to the junction of euchromatin and heterochromatin (Yq12), distal to the AZF gene location (Yq11). CONCLUSIONS: This study supports the hypothesis that in Y/A translocations infertility might be related to meiotic disturbances with spermatogenetic arrest. In addition, sex chromosome molecular investigations, performed on single spermatids, suggest a highly increased risk of producing chromosomally abnormal embryos.