Maternal MTHFR 677C>T genotype and dietary intake of folate and vitamin B12: their impact on child neurodevelopment

Using the Bayley test, the mental and psychomotor development in a cohort of 253 children were evaluated. Maternal dietary intake of vitamin B-12 and folate was assessed from a semiquantitative questionnaire administered during the first trimester of pregnancy. Maternal genotypes of MTHFR (677C>T and 1298A>C), were ascertained by PCR-RFLP The 677T and 1298C variant alleles were present in 59% and 10% of participants, respectively. A dietary deficiency of vitamin B-12 was negatively associated with mental development (beta = -1.6; 95% Cl = -2.8 to -0.3). In contrast, dietary intake of folate (<400 mg/day) reduced the mental development index only among children of mothers who were carriers of the TT genotype (beta = -1.8; 95% Cl = -3.6 to -0.04; P for interaction = 0.07) Vitamin B-12 and folate supplementation during pregnancy could have a favorable impact on the mental development of children during their first year of life, mainly in populations that are genetically susceptible.