Sperm ultrastructure and meiotic segregation in an infertile 47, XYY man

Summary The majority of 47, XYY males are fertile and contribute to produce chromosomally normal children. In 47, XYY carriers, most meiotic studies indicated that the extra Y chromosomes were lost in the pre‐meiotic stages, but in some cases the presence of one X and the two Y chromosomes has been detected during prophase I as an X univalent plus a YY bivalent. The aim of this study was to describe sperm parameters and meiotic segregation in a case of an infertile man with a 47, XYY karyotype. Sperm morphology was evaluated for the first time by transmission electron microscopy highlighting apoptosis and necrosis as the most frequent pathologies. Meiotic segregation was explored by fluorescence in situ hybridisation technique, which makes us capable of detecting aneuploidies of sex chromosomes. The fact that the frequency of 1818XY diploidy was very high reveals an error occurring during first meiotic division. Polymerase chain reaction analysis did not show any Y microdeletion. The combination of these two techniques led us to clarify the status of the spermatogenic process, showing an altered meiotic segregation concomitant with the presence of sperm apoptosis and necrosis in a patient 47, XYY.