In the neonatal period, differential diagnosis should firstly be made with five treatable disorders that can present predominantly with intractable seizures: pyridoxine responsive seizures, pyridox(amine)-5'-phosphate oxidase deficiency, folinic acid-responsive seizures, 3-phosphoglycerate dehydrogenase deficiency, and hyperinsulinemic hypoglycemia (Saudubray et al 2006). The gene discussed is PHGDH; the disease is hyperinsulinemic hypoglycemia, familial, 4.