Adult patients with phenylketonuria (PKU) at the age around 40 years belong to the first patients generation with early treatment of the disease. PKU is caused by an inborn error of the amino acid metabolism and the so far best suitable therapy is an early and strict diet, which is low in phenylalanine.
Besides an early and continuously treatment in childhood, the nutritional and medical support during adolescence and adulthood have been suggested to influence the long-term physical health of adult PKU patients. As many adult PKU patients tend to neglect the necessarily strict diet, they do not get a balanced diet. For PKU patients some nutrients, which may be rare in an unbalanced diet, might help to improve health status, physical and neurological performance and quality of life.
Information about the longitudinal development of the patients status and the influence of the type of their medical care is not available. In this 5 year follow-up the investigators aim to study the quality of life and the medical, nutritional and psychological status of adult PKU patients, in whom corresponding information has already been collected previously.