Beyond classic ALDH7A1 mutations causing (PDE) and pyridox(am)ine-5’-phosphate oxidase (PNPO deficiency), the recent characterization of additional metabolic disorders—including hypophosphatasia and homocystinuria—has broadened the spectrum of vitamin B6-dependent epileptic syndromes [6]. The gene discussed is PNPO; the disease is pyridoxal phosphate-responsive seizures.