Pyridoxamine-5’-phosphate oxidase (PNPO) deficiency is an autosomal recessive PLP-vitamin-responsive epileptic encephalopathy. The emerging feature of PNPO deficiency is the occurrence of refractory seizures in the first year of life. Prematurity and fetal distress, combined with neonatal seizures, are other associated key characteristics. The phenotype results from a dependency of pyridoxal 5′-phosphate (PLP) which regulates several enzymes in the body and is an active form of vitamin B6.
