The purpose of this study is to investigate whether gene polymorphisms of methionine synthase (MTR) and methionine synthase reductase (MTRR) are involved in the risk for NTDs, specifically spina bifida.
We evaluated the association of polymorphisms of three genes affecting vitamin B12-dependent remethylation of homocysteine, transcobalamin (TC), methionine synthase (MTR) and MTR reductase (MTRR), combined or not with methylenetetrahydrofolate reductase (MTHFR), with the risk of having neural tube defect in 40 children with spina bifida and 58 matched controls from South Italy.
For both variants, the risk of having a child with spina bifida appears to increase with the number of high-risk alleles in the maternal genotype: MTR (R1=2.16, 95% CI 0.92-5.06; R2=6.58, 95% CI 0.87-49.67) and MTRR (R1=2.05, 95% CI 1.05-3.99; R2=3.15, 95% CI 0.92-10.85).
In combination with the lowered plasma folate (80-90% 5-methyltetrahydrofolate), our data do not support a major involvement of methionine synthase in the aetiology of SB.