[Diagnostic value of the determination of hyperphenylalaninemia in the newborn].

Blood enzyme immunoassay was carried out to determine the level of phenylalanine in 90 newborn infants. Elevated blood phenylalanine was found in 42 (46.7%) children. These children were re-examined at months 3 and 6. A control group included 48 children of the same age who had normal blood phenylalanine levels. Ten of the 42 patients with hyperphenylalaninemia (HPA) were diagnosed as having various psychoneurological disorders as increased neuroreflex excitability, convulsions, static motor dysfunctions, and mental retardation. The prevalence of anemia, rickets, atopic dermatitis, hypotrophy was statistically higher in infants with HPA.