Mayo Clinic Care Network Content
Definitions

Phenylketonuria


Overview

Phenylketonuria (PKU) is a birth defect that causes an amino acid called phenylalanine to build up in the body. Newborns are screened for PKU.

Symptoms

Untreated PKU can lead to brain damage, mental retardation, behavioral symptoms, or seizures.

Treatments

Treatment includes a strict diet with limited protein.