The SPO11-C631T gene polymorphism and male infertility risk: a meta-analysis.

To evaluate the association between the SPO11 gene C631T polymorphism and the risk of male infertility. We conducted a search on PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), China biology medical literature database (CBM), VIP, and Chinese literature database (Wan Fang) on 31 March 2016. Odds ratio (OR) and 95% confidence interval (95%CI) were used to assess the strength of associations. A total of five studies including 542 cases and 510 controls were involved in this meta-analysis. The pooled results indicated that the SPO11 gene C631T polymorphism was significantly associated with increased risk of male infertility (TT + CT vs. CC: OR = 4.14, 95%CI = 2.48-6.89; CT vs. CC: OR = 4.34, 95%CI = 2.56-7.34; T vs. C: OR = 4.35, 95%CI = 2.58-7.34). Subgroup analysis of different countries proved the relationship between SPO11 gene C631T polymorphism and male infertility risk in Chinese, but not in Iranian peoples. In conclusion, this study suggested that SPO11 gene C631T polymorphism may contribute as a genetic factor susceptible to cause male infertility. Furthermore, more large sample and representative population-based cases and well-matched controls are needed to validate our results.