title: Association between MTHFR A1298C polymorphism and male infertility: A meta-analysis.
abstract: There have been several epidemiological studies evaluating the potential association between the methylenetetrahydrofolate reductase (MTHFR) A1298C polymorphism and the risk of male infertility. However, the results obtained were inconsistent. Therefore, we performed a meta-analysis to further examine the association between the MTHFR A1298C polymorphism and male infertility. A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to January 15th, 2016. A total of 20 studies with 4293 cases and 4507 controls were included. An odds ratio (OR) and a 95% confidence interval (95% CI) were calculated to assess the strength of the association. A cumulative meta-analysis, sensitivity analysis and assessment of the publication bias were also performed in this study. The results showed that in the overall analysis, the association between the MTHFR A1298C polymorphism and male infertility was not significant. A stratified analysis by ethnicity revealed a significant increase in the risk of male infertility in the Asian population with the MTHFR A1298C polymorphism (especially in the heterozygote model: OR=1.20, 95% CI=1.01-1.44, P=0.994; the dominant model: OR=1.23, 95% CI=1.04-1.45, P=0.996; and the allele model: OR=1.20, 95% CI=1.04-1.39, P=0.985) but not in the Caucasian population. In the stratified analyses, no significant association was observed between the different types of male infertility. This meta-analysis suggests the MTHFR A1298C polymorphism may be a potential risk factor for male infertility, especially in the Asian population.
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Guo-Ying
authors.initials: GY
authors.lastname: Yin
authors.affiliation: Department of Biomedical Information and Library, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Experimental Research Center, Liaoning Research Institute of Family Planning, Shenyang, 110031, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Yao-Yan
authors.initials: YY
authors.lastname: Li
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Jing-Yu
authors.initials: JY
authors.lastname: Zhao
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Zhang
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China.
authors.forename: Bai-Qi
authors.initials: BQ
authors.lastname: Wang
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, 300070, China. tangnaijun@tmu.edu.cn.
authors.forename: Nai-Jun
authors.initials: NJ
authors.lastname: Tang
mesh_terms: D044466:Asian People / Q000235:genetics*; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007248:Infertility, Male / Q000208:ethnology / Q000235:genetics*; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D044465:White People / Q000235:genetics
chemical_list: C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)
keywords: male infertility; meta-analysis; methylenetetrahydrofolate reductase; polymorphism