Phenylketonuria:The inherited inability to metabolize (process) theessentialamino acidphenylalaninedue to complete or near-complete deficiency of theenzymephenylalanine hydroxylase.
Newborns are screened for phenylketonuria (PKU) by abloodtest, usually with the Guthrie card bloodspot obtained from a heelprick.
Treatment is with a special diet lowinphenylalanine. The goal is to normalize the levels of phenylalanine andtyrosinein the blood to prevent brain damage. Failure of treatment results in profound irreversiblemental retardation, microcephaly (an abnormally small head), epilepsy, and behavior problems. It is clear that if thedietis not followed closely, especially duringchildhood, some impairment is inevitable.Maternal phenylketonuriarequires a diet low in phenylalanine.
Phenylketonuria is inherited in anautosomal recessivemanner, as are lesser degrees of苯丙氨酸羟化酶缺乏症. Phenylketonuria is abbreviated and commonly referred to as PKU.
