Growing up with a Chronic Disease A Survey of Children with PKU in Sweden

Abstract: Phenylketonuria (PKU) is an inborn, metabolic disease affecting the enzyme phenylalanine hydroxylase, which converts phenylalanine to tyrosine. Since 1965, all Swedish patients are treated with a diet from the neonatal period, while patients without treatment become severely mentally retarded. This thesis presents a recent survey of intelligence, adjustment, and coping among Swedish patients with PKU aged 8-19 years. In Study I the patients’ blood phenylalanine level was in accordance with treatment norms and they were normal in terms of intelligence and adjustment. The next study was a comparison of adjustment between patients with PKU, patients with neurobehavioral disorders, and patients with obesity. A reference group with matched non-clinical children was included. In this comparison, patients with PKU did not differ from the healthy children. Patients with neurobehavioral disorders were the least adjusted, and patients with obesity differed from the reference group and from patients with PKU in some respects, indicating less work capacity and internalising problems. Study II was undertaken for methodological reasons and showed that the measure of adjustment was reliable and valid. Study III was an investigation of psychological mechanisms associated with adherence to the dietetic therapy in PKU. The results showed that parents’ problem-focused coping was the main factor behind good adherence. A marked transition to self-care was recommended to enhance the patients’ motivation to continue with the diet into adulthood. This thesis concludes that the good outcome among the Swedish patients is due to general improvement of the treatment, but a contributing factor can be the high and fairly equal standards of living in the Swedish society.