RESUMEN
OBJECTIVES: To investigate how maternal MTR gene polymorphisms and their interactions with periconceptional folic acid supplementation are associated with the incidence of ventricular septal defects (VSD) in offspring. METHODS: A case-control study was conducted, recruiting 426 mothers of infants with VSD under one year old and 740 mothers of age-matched healthy infants. A questionnaire survey collected data on maternal exposures, and blood samples were analyzed for genetic polymorphisms. Multivariable logistic regression analysis and inverse probability of treatment weighting were used to analyze the associations between genetic loci and VSD. Crossover analysis and logistic regression were utilized to examine the additive and multiplicative interactions between the loci and folic acid intake. RESULTS: The CT and TT genotypes of the maternal MTR gene at rs6668344 increased the susceptibility of offspring to VSD (P<0.05). The GC and CC genotypes at rs3768139, AG and GG at rs1050993, AT and TT at rs4659743, GG at rs3768142, and GT and TT at rs3820571 were associated with a decreased risk of VSD (P<0.05). The variations at rs6668344 demonstrated an antagonistic multiplicative interaction with folic acid supplementation in relation to VSD (P<0.05). CONCLUSIONS: Maternal MTR gene polymorphisms significantly correlate with the incidence of VSD in offspring. Mothers with variations at rs6668344 can decrease the susceptibility to VSD in their offspring by supplementing with folic acid during the periconceptional period, suggesting the importance of periconceptional folic acid supplementation in genetically at-risk populations to prevent VSD in offspring.