Association between XRCC1 single-nucleotide polymorphisms and infertility with idiopathic azoospermia in northern Chinese Han males.

X-ray repair cross-complementing group 1 (XRCC1) is a scaffold protein that plays a critical role in DNA base excision repair. To explore the association between XRCC1 single-nucleotide polymorphisms and infertility with idiopathic azoospermia in a northern Chinese Han population, PCR restriction fragment length polymorphism was used to genotype a SNP locus (rs25487) of XRCC1 in 112 patients with idiopathic azoospermia and 156 healthy controls. Furthermore, nucleotide sequences were sequenced. The results showed that, compared with GG genotype, the GA and GA+AA genotypes showed a significant association with an increased risk of idiopathic azoospermia (OR 2.119, 95% CI 1.245-3.606, P=0.005), (OR 2.052, 95% CI 1.227-3.431, P=0.006) respectively. Meanwhile, the A allele frequency was significantly higher in azoospermic patients than that in controls (OR 1.472, 95% CI 1.029-2.105, P=0.034). The substitutions bring about an amino acid alteration: G→A changes the arginine residue into glutamine. In conclusion, the SNP locus rs25487 of XRCC1 could be a marker for genetic susceptibility to idiopathic azoospermia and the A allele might be a risk gene of idiopathic azoospermia in the northern Chinese Han population.