A neuropsychiatric perspective of phenylketonuria I: overview of phenylketonuria and its neuropsychiatric sequelae.

Phenylketonuria (PKU) is an autosomal recessive metabolic genetic disorder that is associated with neuropsychiatric sequelae of varying severity. The natural history, epidemiology, and a history of the medical understanding and approaches to treatment of PKU are presented. Neurocognitive and neuropsychiatric sequelae of patients with untreated, early-treated, and continuously-treated PKU are described, and possible mechanisms for the symptoms are proposed. The authors propose an integrated approach to management of patients with PKU.