SUSTAINED ATTENTION IN UNTREATED NON-PKU-HYPERPHENYLALANINEMIA

Twenty-four untreated adolescent and adult patients with non-PKU hyper phenylalaninemia (HPA) (serum Phe levels < 600 mu mol/L) and 24 health y controls matched for age, sex, and IQ were investigated for simple m otor reaction time and sustained attention, which are prolonged in pat ients with mild or classical phenylketonuria (PKU). Patients with HPA were of normal intelligence and did not differ significantly from heal thy controls in their test results. For HPA patients, reaction times a nd sustained attention were not significantly influenced by serum phen ylalanine concentrations. We conclude that dietary treatment is not ne cessary in patients with non-PKU HPA.