title: Association between 5, 10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and congenital heart disease: A meta-analysis.
abstract: BACKGROUND
  Inconsistent results were reported in recent literature regarding the association between methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and the susceptibility of congenital heart disease (CHD). In this study, we performed a meta-analysis to investigate the associations by employing multiple analytical methods.
  
  
  METHODS
  Literature search was performed and published articles were obtained from PubMed, Embase and CNKI databases based on the exclusion and inclusion criteria. Data were extracted from eligible studies and the crude odds ratios and their corresponding 95% confidence intervals (CIs) were calculated using random or fix effects model to evaluate the associations between the MTHFR C677T/A1298C polymorphisms and CHD development. Subgroup based analysis was performed by Hardy-Weinberg equilibrium, ethnicity, types of CHD, source of control and sample size.
  
  
  RESULTS
  Twenty-four eligible studies were included in this meta-analysis. Significant association was found between fetal MTHFR C677T polymorphism and CHD development in all genetic models. The pooled ORs and 95% CIs in all genetic models indicated that MTHFR C677T polymorphism was significantly associated with CHD in Asian, but not Caucasian in subgroup analysis. The maternal MTHFR C677T polymorphism was not associated with CHD except for recessive model. Moreover, neither maternal nor fetal MTHFR A1298C polymorphism was associated with CHD.
  
  
  CONCLUSIONS
  The fetal MTHFR C677T polymorphism may increase the susceptibility to CHD. Fetal MTHFR C677T polymorphism was more likely to affect Asian fetus than Caucasian. The MTHFR A1298C polymorphism may not be a risk of congenital heart disease.
authors.affiliation: Kunming Yan'an Hospital, Kunming 650051, Yunnan, People's Republic of China.
authors.forename: Wenju
authors.initials: W
authors.lastname: Wang
authors.affiliation: Kunming Yan'an Hospital, Kunming 650051, Yunnan, People's Republic of China.
authors.forename: Zongliu
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Kunming Yan'an Hospital, Kunming 650051, Yunnan, People's Republic of China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Wang
authors.affiliation: Kunming Yan'an Hospital, Kunming 650051, Yunnan, People's Republic of China.
authors.forename: Chuanyu
authors.initials: C
authors.lastname: Wei
authors.affiliation: Kunming Yan'an Hospital, Kunming 650051, Yunnan, People's Republic of China.
authors.forename: Yaxiong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Kunming Yan'an Hospital, Kunming 650051, Yunnan, People's Republic of China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Jiang
keywords: Association; Congenital heart disease; Folic acid; MTHFR; Meta-analysis; Polymorphism