Association of XRCC1 gene polymorphisms with idiopathic azoospermia in a Chinese population

Aim: To assess the possible role of genetic polymorphisms in DNA repair gene XRCC1 (X-ray repair cross-complementing group 1) during spermatogenesis by investigating the associations of one promoter polymorphism (T-77C) and two exonic polymorphisms (Arg 194Trp and Arg399Gln) in XRCC1 gene with risk of idiopathic azoospermia in a Chinese population. Methods: The genotype and allele frequencies of three observed polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism based on a Chinese population consisting of 171 idiopathic azoospermia subjects and 247 normal-spermatogenesis controls. Results: In our study, all the observed genotype frequencies were in agreement with Hardy-Weinberg equilibrium. The 399A (GA+AA) allele frequency for idiopathic azoospermia subjects and controls was 0.216 and 0.269, respectively. Compared with GG genotype, the AA genotype of Arg399Gln showed a significant association with a decreased risk of idiopathic azoospermia (odds ratio = 0.315; 95% confidence interval = 0.12-0.86). However, no significant differences were found between the cases and controls for T-77C and Arg194Trp polymorphisms. The major haplotypes of XRCC1 gene were TCG, TTG and TCA, whereas no haplotypes appeared to be significantly associated with idiopathic azoospermia based on the cutoff of P < 0.05. Conclusion: In a selected Chinese population, AA genotype of Arg399Gln appears to contribute to a decreased risk of idiopathic azoospermia, while we have not any evidence of involvement of XRCCl T-77C and Arg194Trp polymorphisms in idiopathic azoospermia.