摘要Several studies have reported a relationship between the length of the CAG-repeat in the polymerase γ(POLG)gene and male infertility.However,other studies have not reproduced this result.In our study,the POLG-CAG-repeat length was analyzed in 535 healthy individuals from six Chinese Han populations living in different provinces.The frequencies of 10-CAG alleles and genotypes were high(97.38 and 94.13%,respectively),with no significant difference among the six Chinese Han populations.Furthermore,we determined the distribution of the POLG-CAG-repeat in 150 infertile men and 126 fertile men.Our study suggested that the distributions of POLG-CAG-repeat alleles and genotypes were not significantly different between infertile(95.67 and 92.67%,respectively)and fertile men(97.22 and 94.44%,respectively).In a subsequent meta-analysis,combining our data with data from previous studies,a comparison of the CAG-repeat alleles in fertile versus infertile men showed no obvious risk for male infertility associated with any particular allele(pooled odds ratio(OR)=0.94; 95% confidence interval(CI):0.60-1.48).The significance level was not attained with any of the following genetic models: homozygote comparison(not 10/not 10 versus 10/10:OR=1.34; 95% CI:0.66-2.72),heterozygote comparison(10/not 10 versus 10/10: OR=1.04; 95% CI:0.78-1.38),dominant model comparison(not 10/not 10+10/not 10 versus 10/10: OR=1.08; 95% CI: 0.79-1.47)and recessive genetic comparison(not 10/not 10 versus 10/not 10+10/10:OR=1.31; 95% CI:0.68-2.55).In conclusion,there is no significant difference of the frequencies of POLG-CAG.repeat variants among six Chinese Han populations,and this polymorphism may not be associated with Chinese male infertility.On the basis of a meta-analysis,there is no obvious association between CAG-repeat variants of the POLG gene and male infertility.