Meiotic segregation analysis by FISH investigation of spermatozoa of a 46,Y,der(X),t(X;Y)(qter -> p22 :: q11 -> qter) carrier

Chromosome analysis performed on a 30-year-old man revealed a 46,Y,der(X),t (X;Y)(qter --> p22::q11 --> qter) karyotype, confirmed by fluorescence in s itu hybridization (FISH). The man was of short stature, and no mental retar dation was noticed; genitalia and testes were normal, as were the patient's FSH, LH, and testosterone blood levels. Sperm analysis showed azoospermia at the time of the first sampling and severe oligozoospermia, with 125,000 spermatozoa/milliliter, at the time of the second sampling. The sperm gonos omal complement of this patient and of a 46,XY donor were analyzed using mu lticolor FISH with X- and Y-chromosome probes. Our results clearly indicate d that germinal cells carrying the translocation are able to complete the m eiotic process by producing spermatozoa compatible with normal embryonic de velopment, with more than 80 % of the spermatozoa having either a Y chromos ome or a der(X); however, a high level of spermatozoa with gonosomal disomi es was observed. We also found a significant increase in the frequency of a utosomal disomies in the carrier, which would suggest an interchromosomal e ffect. All previously reported cases in adult males were associated with az oospermia; testicular histological studies, performed in patients carrying the same X;Y translocation, showed spermatogenetic arrest after pachytene. To our knowledge, this is the first molecular analysis of the gonosomal com plement in spermatozoa of men with a t(X;Y)(qter --> p22::q11 --> qter). Co pyright (C) 2001 S. Karger AG, Basel.