Purpose: To describe sperm morphology and meiotic segregation in the case of a man with a 46 XY/ 47 XY + 18 mosaic karyotype.
Materials and methods: A 25-year-old man came to our Centre for semen analysis. Morphological sperm evaluation was performed by light and electron microscopy; meiotic segregation was examined by fluorescence in situ hybridisation (FISH) technique using probes for chromosomes 18, X and Y. PCR was carried out on DNA from peripheral blood lymphocytes to analyze Y microdeletions.
Results: Mathematically elaborated transmission electron microscopy data highlighted a low number of sperm devoid of ultrastructural defects, and the presence of characteristics of apoptosis and immaturity. FISH showed the presence of aneuploidies of chromosome 18 and sex chromosomes.
Conclusions: In this case of mosaicism morphological and meiotic spermatogenetic impairment is shown, as well as structural chromosomal alterations.