• PMID: 21102476
• Gene Name: POLG
• Condition: Male infertility
• Association: 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 obv
• Mutation: CAG-repeat polymorphisms
• Population size: 811
• Population details: 811 (535 healthy individuals, 150 infertile men and 126 fertile men)
• Sex: Male
• Infertility type: Male infertility
• Other associated phenotypes: Male infertility

CAG-repeat variant in the polymerase ? gene and male infertility in the Chinese population: a meta-analysis

Liu SY, Zhang CJ, Peng HY, Yao YF, Shi L, Chen JB, Lin KQ, Yu L, Shi L, Huang XQ, Sun H, Chu JY.

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. FAU - Liu, Shu-Yuan AU - Liu SY AD - Department of Medical Genetics, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming 650118, China. FAU - Zhang, Chang-Jun AU - Zhang CJ FAU - Peng, Hai-Ying AU - Peng HY FAU - Yao, Yu-Feng AU - Yao YF FAU - Shi, Lei AU - Shi L FAU - Chen, Jin-Bao AU - Chen JB FAU - Lin, Ke-Qin AU - Lin KQ FAU - Yu, Liang AU - Yu L FAU - Shi, Li AU - Shi L FAU - Huang, Xiao-Qin AU - Huang XQ FAU - Sun, Hao AU - Sun H