Cigarette smoking and aneuploidy in human sperm

Cigarette smoke contains chemicals which are capable of inducing aneuploidy in experimental systems. These chemicals have been shown to reach the male reproductive system, increasing oxidative DNA damage in human sperm and lo wering semen quality. We have examined the association between smoking and aneuploid sperm by studying 31 Chinese men with similar demographic charact eristics and lifestyle factors except for cigarette smoking. None of the me n drank alcohol. These men were divided into three groups: nonsmokers (10 m en), light smokers (< 20 cigarettes/day, 11 men), and heavy smokers (greate r than or equal to 20 cigarettes/day, 10 men). There were no significant di fferences in semen parameters or in age across groups. Two multi-color fluo rescence in situ hybridizations (FISH) were performed: two-color FISH for c hromosomes 13 and 21, and three-color FISH for the sex chromosomes using ch romosome 1 as an internal autosomal control for diploidy and lack of hybrid ization. The mean hybridization efficiency was 99.78%. The frequency of dis omy 13 was significantly higher in light and heavy smokers than in nonsmoke rs, while no significant differences in the frequency of disomy 21, X or Y were observed across groups. Significant inter-donor heterogeneity in every category of disomic sperm examined was found in both light and heavy smoke rs, while in nonsmokers only XY disomy showed significant inter-donor diffe rences. Thus, we conclude that cigarette smoking may increase the risk of a neuploidy only for certain chromosomes and that men may have different susc eptibilities to aneuploidy in germ cells induced by cigarette smoking. (C) 2001 Wiley-Liss, Inc.