Comparative study of disomy and diploidy rates in spermatozoa of fertile and infertile men: a donor-adapted protocol for multi-colour fluorescence in situ hybridization (FISH).

Spermatozoa from seven healthy donors (two of whom had already fathered children) and five infertile patients taking part in the local programme of intracytoplasmic sperm-injection (ICSI) were investigated for the disomy rates of chromosomes 13/21, 18, X and Y as well as for the diploidy rates. Two- and three-colour fluorescence in situ hybridization (FISH) was applied after a donor-adapted decondensation pre-treatment: in a preliminary decondensation series the optimum fluorescence signals were individually determined by variation of the concentration of the decondensation reagents and the duration of incubation with these reagents. Strict scoring criteria were applied. The average disomy rates ranged from 0.10% (chromosomes 13/21) to 0.44% (disomy XY) in the infertile donors and from 0.07% (disomy XX) to 0.36% (disomy XY) in the controls. The average diploidy rates were 0.22% and 0.20% for the infertile donors and the controls respectively. There was no statistically significant difference between the two groups with respect to the disomy and diploidy rates. Within the two groups there were inter-individual differences which were partly statistically significant, indicating considerable inter-donor variation of the aneuploidy rates.