Abstract
BackgroundMethylenetetrahydrofolate reductase (MTHFR) is an important enzyme for folate metabolism in humans; it is encoded by the MTHFR gene. Several studies have assessed the association between MTHFR C677T polymorphism and the risk of congenital heart defects (CHDs), while the results were inconsistent.Methods and FindingsMultiple electronic databases were searched to identify relevant studies published up to July 22, 2012. Data from case-control and TDT studies were integrated in an allelic model using the Catmap and Metafor software. Twenty-nine publications were included in this meta-analysis. The overall meta-analysis showed significant association between MTHFR C677T polymorphism and CHDs risk in children with heterogeneity (P heterogeneity = 0.000) and publication bias (P egger = 0.039), but it turned into null after the trim-and-fill method was implemented (OR = 1.12, 95% CI = 0.95–1.31). Nevertheless, positive results were obtained after stratified by ethnicity and sample size in all subgroups except the mixed population. For mothers, there was significant association between the variant and CHDs without heterogeneity (P heterogeneity = 0.150, OR = 1.16, 95% CI = 1.05–1.29) and publication bias (P egger = 0.981). However, the results varied across each subgroup in the stratified analysis of ethnicity and sample size.ConclusionsBoth infant and maternal MTHFR C677T polymorphisms may contribute to the risk of CHDs.
Highlights
Congenital heart defects (CHDs) refer to the defects in the structure of the heart and great vessels present at birth
The deficiency in folic acid is known to result in hyperhomocysteinemia, which is one of the proved risk factors related to the occurrence of congenital heart defect (CHD) [3]
We included case-control studies and transmission/disequilibrium test (TDT) with human subjects that investigated the association between Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and CHDs risk in all languages
Summary
Congenital heart defects (CHDs) refer to the defects in the structure of the heart and great vessels present at birth. The incidence of CHDs is reported to be 5–8%, making them one of the most common congenital disorders in newborns. They are the leading causes of infant death worldwide, with a mortality of 24.1% [1]. Some studies have identified the association between the lack of folate ( called folic acid or vitamin B9) and CHDs risk. The deficiency in folic acid is known to result in hyperhomocysteinemia, which is one of the proved risk factors related to the occurrence of CHDs [3]. Several studies have assessed the association between MTHFR C677T polymorphism and the risk of congenital heart defects (CHDs), while the results were inconsistent
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
