The thermolabile variant of methylenetetrahydrofolate reductase (MTHFR) is not a major risk factor for neural tube defect in American Caucasians. The NTD Collaborative Group.

Mutations in the gene for methylenetetrahydrofolate reductase (MTHFR) have been implicated as a risk factor in the formation of neural tube defects. We investigated this gene in a series of 65 sporadic American Caucasian patients with lumbosacral NTD and their unaffected parents, using both case-control design and assessment of linkage disequilibrium. We found no evidence to support mutations in MTHFR as a significant risk factor for NTD in this population.