FOLH1 and neural tube defect: While additional research is needed to clarify the functional role of the FOLH1 484T>C polymorphism, together these studies suggest a functional effect of the FOLH1 484 T>C SNP, such that the T-allele is associated with greater RBC folate levels, greater response of RBC folate to naturally occurring food folate intake, while the hypofunctional variant is associated with NTD risk.