ALDH7A1 and hyperinsulinemic hypoglycemia, familial, 4: Pyridoxine-dependent epilepsy related to ALDH7A1 deficiency (PDE-ALDH7A1; OMIM #266100) is a rare developmental epileptic encephalopathy characterized by refractory seizures that respond to a high dose of pyridoxine (vitamin B6) [1].