Incidence of aneuploid spermatozoa among infertile men studied by multicolor fluorescence in situ hybridization.

We studied by fluorescence in situ hybridization the frequency of aneuploidy in spermatozoa of 12 infertile men: 8 with normal or nearly normal semen analysis values and 4 with oligo-astheno-teratozoospermia. The control group consisted of 18 normal healthy fertile men. Probes for chromosome 1 and 7 were used and 10,000 spermatozoa per individual were scored. The hybridization efficiency was good (higher than 98%). In the group with nearly normal semen analysis values the frequencies of spermatozoa disomic for chromosome 1 or chromosome 7 were 0.08% and 0.07%, respectively, and not elevated compared to controls (0.10% and 0.06%, respectively). The frequency of diploid spermatozoa was 0.17%, not significantly different from the control group (0.15%) either. In the group of oligoastheno-teratozoospermic men both the frequencies of disomic cells for chromosome 1 (0.22%) and for chromosome 7 (0.13%) and of diploid spermatozoa (0.56%) were significantly higher compared to controls, although this was mainly due to one patient with high frequencies of hyperploid sperm. The results indicate that infertility may be a risk factor for chromosomal aneuploidy in spermatozoa.

Detection of aneuploidy in human spermatozoa of normal semen donors by fluorescence in situ hybridization.

We have studied human spermatozoa from 24 normal, healthy unexposed men, 18 of whom were semen donors at the Sperm Bank in Turku, using multicolor fluorescence in situ hybridization with two chromosome-specific probes. The possible age-related increase in aneuploidy frequencies was assessed. Ten thousand spermatozoa were scored per individual for the presence of hyperploid, i.e., disomic and diploid, cells. The overall hybridization efficiency was 98.8%. The frequency of spermatozoa with two chromosome 1 signals was 11.5 +/- 5.2/10,000. The frequency of spermatozoa with two chromosome 7 signals was 6.4 +/- 3.9/10,000. Diploidy was present in 15.0 +/- 8.9/10,000 spermatozoa. Interindividual variation was quite large. No statistically significant correlation between age of the donors (range = 20-46 years) and the frequency of hyperploid spermatozoa was observed. The results give background information on the incidence of hyperploid spermatozoa in unexposed men and encourage the use of this novel technique of future studies on genetic effects in men exposed to potentially aneuploidogenic agents.