Spina bifida and folate-related genes: a study of gene-gene interactions

Purpose: To assess whether interactions of common alleles of two folate genes contribute to spina bifida risk. Methods: Case-control study, comparing 203 children with spina bifida to 583 controls. Results: Homozygosity for the 677C-T allele of 5,10-methylenetetrahydrofolate reductase (MTHFR) alone was associated with an odds ratio for spina bifida of 1.57 (95% confidence interval [CI], 1.02–2.38). For the 844ins68 allele of cystathionine-β-synthase alone, the odds ratio was 0.83 (95% CI, 0.39–1.64). For the joint genotype, the odds ratio was 3.69 (95% CI, 1.04–13.50). Conclusions: Interactions between common alleles of folate genes might contribute to the risk for spina bifida.