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Phenylketonuria
A congenital defect in the metabolism of the amino acid, phenylalanine. Individuals with phenylketonuria (PKU) lack an enzyme, phenylalanine hydroxylase. This enzyme breaks down phenylalanine, a normally occuring amino acid. Failure to metabolize phenylalanine results in its accumulation causing severe brain injury and mental retardation.

Infants with PKU who receive early treatment of dietary restriction of phenylalanine, have a much better outcome than those who are not treated. Hence, early treatment is essential.

Children with PKU appear normal at birth and the obvious signs of the disease may not appear until brain damage has already occurred. Therefore, virtually all infants in the U.S. are tested for PKU at birth. You should ask your pediatrician for the results of this test at your first newborn check-up.
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Date Last Modified: 08/28/2003 09:43