Phenylketonemia in phenylketonuria.

Abstract

Phenylpyruvic acid (PPA) was not found in the plasma of non-phenylketonuric subjects or phenylketonuric heterozygotes but it was present in the plasma of patients with untreated “classical” phenylketonuria. The mean plasma PPA level in 96 patients was 0.84 mg/100 ml with a range of from 0.10 to 1.68 mg/100 ml. Plasma phenylalanine, plasma PPA and urinary PPA levels were significantly intercorrelated and were dependent on the dietary phenylalanine intake. Five subjects with “atypical” phenylketonuria had PPA levels in the plasma consistent with their plasma phenylalanine levels. A 3 week old girl with untreated “classical” phenylketonuria had significant amounts of PPA in the plasma but almost none in the urine.