RESUMO
<p><b>OBJECTIVE</b>To study the association between reduced folate carrier gene (RFC1) polymorphism and congenital heart defects (CHD) as well as cleft lip with or without cleft palate (CLP) and to provide epidemiological evidence on genetic markers of CHD and CLP.</p><p><b>METHODS</b>RFC1 (A80G) genotype was detected using RFLP-PCR for blood DNA of the 67 triads with nonsyndromic CHD-affected child, the 82 triads with child-affected cleft lip with or without CLP and the 100 control families without child-affected birth defects. We performed a family-based association test and analyzed the interaction between RFC1 A80G genotype and maternal periconceptional supplementation of folic acid.</p><p><b>RESULTS</b>Offspring of mothers who did not take folic acid had an elevated risk for CHD when comparing with offspring of mothers who did (OR = 2.68, 95% CI: 1.14 - 6.41). There was a statistical association between the risk of CHD and maternal periconceptional folic acid supplementation (chi(2) = 6.213, P < 0.05). In the family-based association test, G allele was positively associated with an increased risk for children CHD (Z = 2.140, P < 0.05) while G allele of RFC1 (A80G) polymorphism might increase the risk for CHD. Elevated risks for either CLP group were not observed between RFC1 genotype using or not using folic acid.</p><p><b>CONCLUSION</b>Our findings suggested that the G allele was likely to be a genetically susceptible allele for CHD. There was possible association between offspring with GG, GA genotype and maternal periconceptional folicacid deficiency.</p>