PKU

PKU Phenylketonuria, a metabolic disease that is due to the inherited inability to process the essential amino acid phenylalanine. The biochemical basis of PKU is complete or near-complete deficiency of the enzyme phenylalanine hydroxylase. Newborns in many countries are now routinely screened for PKU via a blood test. Treatment of PKU involves a special diet that is low in phenylalanine. The goal is to normalize the levels of phenylalanine and tyrosine in the blood to prevent brain damage. Failure or lack of treatment results in profound irreversible mental retardation, microcephaly, epilepsy, and behavior problems. If an appropriate diet is not followed closely, especially during childhood, some impairment is inevitable. PKU is inherited in an autosomal recessive manner, as are lesser degrees of phenylalanine hydroxylase deficiency. See also Guthrie test; phenylalanine hydroxylase deficiency; PKU, maternal.