Aneuploidy rate in spermatozoa of selected men with abnormal semen parameters

A large proportion of patients with oligoasthenoteratozoospermia (OAT) have an abnormal karyotype and hence they produce aneuploid gametes, However, a normal karyotype does not exclude the chance of having germ cell aneuploid y, since an altered intra-testicular environment not only damages spermatog enesis, but may also disrupt the mechanisms controlling chromosomal segrega tion during meiosis, Therefore, this study was undertaken to evaluate the r ate of aneuploidy in the spermatozoa of selected patients with abnormal spe rm parameters. For this purpose, sperm aneuploidy rate for chromosomes 8, 1 2, 18, X and Y was evaluated by multicolour fluorescence insitu hybridizati on (FISH) in nine patients with teratozoospermia alone and 19 OAT patients of presumably testicular origin. Thirteen normozoospermic healthy men serve d as controls. Patients with teratozoospermia or OAT had significantly grea ter disomy and diploidy rates compared with controls, whereas the rate of n ullisomy was similar. XY disomy was very low in all groups, suggesting that chromosomal non-disjunction occurs mainly during the second meiotic divisi on. Autosome 12 disomy rate was low in both patients and controls. There wa s a marked variability of total sperm aneuploidy rate in both groups of pat ients. Sperm aneuploidy rate was negatively correlated with sperm concentra tion and particularly with the percentage of normal forms. In conclusion, p atients with teratozoospermia or OAT have an increased rate of sperm aneupl oidy, This increase is similar in both groups, suggesting that teratozoospe rmia may be the critical sperm parameter associated with aneuploidy.