This large mid-thoracic meningomyelocele is another form of neural tube defect (NTD). The genetic polymorphisms due to mutations in the methylene tetrahydrofolate reductase gene may increase the risk for NTDs. Folate is a cofactor for this enzyme, which is part of the pathway of homocysteine metabolism in cells. The C677T and the A1298C mutations are associated with elevated maternal homocysteine concentrations and an increased risk for NTDs in fetuses. Mothers who supplement their diets with folate prior to and during pregnancy can often reduce this risk.