Phenylketonuria

The long-term outlook for patients with PKU is excellent if they adhere to therapy and if blood phenylalanine (phe) levels remain within the therapeutic range. Life expectancy should be normal, and most patients function independently in adult life.

Neurocognitive outcome in treated patients

Although intellectual disability is prevented by the initiation of treatment shortly after birth, treated patients with PKU have an increased incidence of ADHD, psychiatric disorders, and deficits in executive functioning, including reduced information processing speed.[22]Christ SE, Huijbregts SC, de Sonneville LM, et al. Executive function in early-treated phenylketounuria: profile and underlying mechanisms. Mol Genet Metab. 2010;99(suppl 1):S22-32. http://www.ncbi.nlm.nih.gov/pubmed/20123466?tool=bestpractice.com Most of these adverse outcomes can be related to mean blood phe levels. Patients are typically treated with dietary therapy, which is rigid and often unpalatable. As a result, the proportion of patients maintaining adequate metabolic control declines in adulthood.