Isolated seizures are associated with disorders such as: pyridoxine-responsive seizures, non-ketotic hyperglycinemia (NKH), dihydropyrimidine dehydrogenase deficiency, sulfite oxidase deficiency (either isolated or as part of molybdenum cofactor deficiency), 4-aminobutyrate aminotransferase (GABA transaminase) deficiency, folinic acid-responsive seizures, 3-phosphoglycerate dehydrogenase deficiency, guanidinoacetate methyltransferase (GAMT) deficiency, and glucose transporter (GLUT-1) deficiency. This evidence concerns the gene GAMT and hyperinsulinemic hypoglycemia, familial, 4.