title: Chromosomal abnormalities in human sperm.
abstract: The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.
mesh_terms: D000782:Aneuploidy; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D025063:Chromosome Disorders; D005260:Female; D006570:Heterochromatin / Q000648:ultrastructure; D006801:Humans; D007621:Karyotyping; D008297:Male; D009369:Neoplasms / Q000532:radiotherapy; D009865:Oocytes / Q000166:cytology; D011878:Radiotherapy / Q000009:adverse effects; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000002:abnormalities* / Q000166:cytology / Q000528:radiation effects
chemical_list: D006570:Heterochromatin