carrying epilepsy-associated variants in the vitamin B6 metabolism gene display allele- and diet-dependent phenotypes.

Pyridox(am)ine 5 -phosphate oxidase (PNPO) catalyzes the rate-limiting step in the synthesis of pyridoxal 5 -phosphate (PLP), the active form of vitamin B6 required for the synthesis of neurotransmitters gamma-aminobutyric acid (GABA) and the monoamines. Pathogenic variants in have been increasingly identified in patients with neonatal epileptic encephalopathy and early-onset epilepsy. These patients often exhibit different types of seizures and variable comorbidities.