[Influence of aging and sex on chromosome 21 segregation in human lymphocytes]

OBJECTIVE: To determine the influence of aging and sex on the segregation of chromosome 21. METHODS: Lymphocytes were obtained from healthy donors of different ages, both sexes, and were treated with cytochalasin B. Binucleated cells were hybridized with chromosome 21 specific probe, and simultaneously, chromosome 21 loss and non-disjunction were detected. RESULTS: The coefficients of correlation between age and binucleated cells containing 4, 2 and 6 signals were -0.35(P<0.01), 0.18 and 0.38(P<0.01) respectively. The coefficients of correlation between age and nondisjunction of chromosome 21 and micronuclei were 0.56(P<0.01) and 0.70(P<0.01) respectively. CONCLUSION: There is a significant increase with age in the number of micronuclei and missegregation. Nondisjunction of chromosome 21 is much more frequent than loss in vivo and in vitro. No significant difference in nondisjunctioin between male and female was noted. Age effect is more significant in female than in male.