Neurological manifestations of folate transport defect: case report and review of the literature.

Folate is essential for normal brain development. This report describes a 15-month-old boy who presented with generalized and focal seizures and a decline in mental status. Laboratory tests revealed low folate levels in blood (1.13 nmol/L) and cerebrospinal fluid, accompanied by pancytopenia. Bone marrow aspiration confirmed the presence of megaloblastic anemia. Treatment with high-dose intravenous folinic acid led to normalization of cerebrospinal folate levels. These findings apparently indicate a defect in folic acid transport to the central nervous system. A clinical picture of developmental arrest, seizures, somnolence, and megaloblastic anemia should alert physicians to the possibility of folate deficiency.