Energy deficiency can cause seizures in various metabolic disorders including mitochondrial diseases, glucose transporter type 1 (GLUT-1) deficiency, guanidinoacetate methyltransferase (GAMT) deficiency, and disorders causing hypoglycemia including fatty acid oxidation defects, disorders of gluconeogenesis, and glycogen storage disorders (Table 1). This evidence concerns the gene SLC2A1 and hyperinsulinemic hypoglycemia, familial, 4.