Associations of C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR) gene with male infertility risk: A meta-analysis

Abstract

PurposeMethylenetetrahydrofolate reductase is one of the key enzymes in folate metabolism. But the association between polymorphism and the risk of male infertility is still controversial. Therefore, this study used a meta-analysis on the collection of data to analyze MTHFR gene C677T polymorphism (known as c.665 C>T, rs1801133, p.Ala222Val). MethodsPubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and Wan fang. Data were searched to identify eligible studies. We sifted the data collection by Hardy-Weinberg equilibrium calculator and used odds ratios (ORs) and 95% confidence intervals (95% CIs) to conduct data through RevMan5.0 and StataSE12.0 software. ResultsA total of 15 studies have 3853 patients with infertility and 3613 healthy controls in this meta-analysis. Our results showed that T variant of MTHFR C677T gene polymorphism was significantly associated with an increased risk of male infertility (forT vs. C: OR=1.38, 95% CI=1.18–1.63; for TT vs. CC: OR=1.86, 95% CI=1.36–2.54; for CT vs. CC: OR=1.34, 95% CI=1.03–1.74; for TT vs. CT: OR=1.52, 95% CI=1.26–1.84; for TT vs. CT+CC: OR=1.42, 95% CI=1.19–1.70; for TT+CT versus CC: OR=1.46, 95%CI=1.05–2.04). In addition, the results indicated that T allele had the positive association which was driven by East-asian populations (random: OR=1.44, 95% CI=1.2–1.74; fixed: OR=1.39, 95% CI=1.20–1.61), Middle-eastern populations (random: OR=1.30, 95% CI=1.05–1.63; fixed: OR=1.30, 95% CI=1.05–1.63) and Mixed-race (random: OR=1.96, 95% CI=1.35–2.85; fixed: OR=1.31, 95% CI=1.20–1.43). ConclusionThis meta-analysis suggests that MTHFR C677T polymorphism is associated with male infertility.