Objectives: To investigate whether genetic variants in methylenetetrahydrofolate reductase (MTHFR) and methylenetetrahydrofolate dehydrogenase (MTHFD) genes are associated with risk of congenital cardiac disease.
Background: Accumulative evidence suggests that hyperhomocysteinaemia is associated with risk of congenital cardiac disease. Inherited polymorphisms in key folate metabolic pathway genes, MTHFR and MTHFD, may influence the efficiency of folate metabolism and plasma level of homocysteine.
Methods: A two-stage case-control study of congenital cardiac disease was conducted by genotyping MTHFR c.1793G>A and four other variants - MTHFR c.677C>T, c.1298A>C, and MTHFD c.1958G>A, c.401C>T - in a Chinese population consisting of 1033 congenital cardiac disease patients and 1067 non-congenital cardiac disease patients.
Results: The variant genotypes of MTHFR c.1793GA/AA were associated with a significantly decreased risk of congenital cardiac disease in two stages combined, with an adjusted odds ratio of 0.67 and a 95% confidence interval of 0.54-0.84 (p = 0.0004). In comparison with wild-type homozygote c.1793GG, the effect was significant in isolated perimembranous ventricular septal defect patients with an adjusted odds ratio of 0.60 and a 95% confidence interval of 0.43-0.83 (p = 0.0003).
Conclusion: These findings indicate that MTHFR c.1793G>A may have a role in susceptibility to sporadic congenital cardiac disease.