Rapidly progressive psychotic symptoms triggered by infection in a patient with methylenetetrahydrofolate reductase deficiency: a case report.

This patient demonstrates the possibility that MTHFR deficiency should be considered in mentally retarded adolescents who display an abnormally elevated plasma level of homocysteine in association with progressive neurological dysfunction and leukoencephalopathy. Febrile infections may be an aggravating factor in patients with MTHFR deficiency.