What is Methylenetetrahydrofolate Reductase Deficiency?

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme that is encoded by the MTHFR gene. Mutations in this gene are associated with MTHFR deficiency which may result in intellectual disability, psychosis, weakness, ataxia, spasticity and homocystinuria due to elevated blood levels of homocystine.