title: Methylenetetrahydrofolate reductase C677T polymorphism  and congenital heart disease: a meta-analysis.
abstract: BACKGROUND
  As a key enzyme in folate metabolism, 5,10- methylenetetrahydrofolate reductase (MTHFR) regulates the homeostasis between DNA synthesis and methylation. Data on the association between the MTHFR C677T polymorphism and congenital heart disease (CHD) are conflicting.
  
  
  METHODS
  To assess the relationship between the MTHFR 677TT genotype and the risk of CHD, we performed a metaanalysis, searching in Pubmed for studies on this topic published in the English language up to 1 December 2010. For each study, we calculated odds ratios (ORs) and 95% confidence intervals (CIs), assuming frequency of allele comparison, homozygote comparison, dominant, and recessive genetic models. We then calculated pooled ORs and 95% CIs. Thirteen studies were included in the meta-analysis.
  
  
  RESULTS
  The MTHFR T allele was associated with a borderline significantly increased risk of CHD in the frequency of allele comparison (T vs. C: OR = 1.160; 95% CI = 0.990- 1.359; p = 0.001 for heterogeneity). The MTHFR TT genotype was not associated with the risk of CHD in the homozygote comparison (TT vs. CC: OR = 1.272; 95% CI = 0.947-1.707; p = 0.028 for heterogeneity), the dominant genetic model (TT + CT vs. CC: OR = 1.127; 95% CI = 0.937-1.355; p = 0.034 for heterogeneity) and the recessive genetic model (TT vs. CTqCC: OR = 1.272; 95% CI = 0.975-1.659; p = 0.030 for heterogeneity). However, a stratification analysis showed that the association between the MTHFR C677T polymorphism and the risk of CHD was evident among Caucasians instead of Asians.
  
  
  CONCLUSIONS
  Our meta-analysis suggests that genotypes for the MTHFR C677T polymorphism might be associated with the risk of CHD among Caucasians.
authors.affiliation: State Key Laboratory of Translational Cardiovascular Medicine, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Nie
authors.forename: Haiyong
authors.initials: H
authors.lastname: Gu
authors.forename: Jie
authors.initials: J
authors.lastname: Gong
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.forename: Dingxu
authors.initials: D
authors.lastname: Gong
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Cong
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Shengshou
authors.initials: S
authors.lastname: Hu
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D016208:Databases, Factual; D005838:Genotype; D006330:Heart Defects, Congenital / Q000235:genetics* / Q000473:pathology; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics* / Q000378:metabolism; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)