A 15-year follow-up of a boy with pyridoxine (vitamin B-6)-dependent seizures with autism, breath holding, and severe mental retardation

Pyridoxine (vitamin B-6 (2q31) dependency is a rare autosomal-recessive dis order that causes a severe seizure disorder of prenatal or neonatal onset. The abnormality appears to inhibit the binding of vitamin B-6 to the enzyme glutamic acid decarboxylase-1, which is needed for the biosynthesis of gam ma -aminobutyric acid (GABA). Most patients with pyridoxine-dependent seizu res require lifelong treatment with pyridoxine. The full range of associate d symptomatology is unknown since fewer than 100 cases have been reported. A majority of cases are mentally retarded. We report a 15-year-old boy with pyridoxine-dependent seizures, nonpyridoxine-dependent seizures, severe me ntal retardation, autistic disorder, aerophagia, breath holding, and self-i njury. This complex outcome should alert clinicians to the wide range of ne uropsychiatric outcomes associated with this disorder.