RT Book, Section A1 Schwahn, Bernd Christian A2 Kline, Mark W. SR Print(0) ID 1182928226 T1 Hyperphenylalaninemias and Phenylketonuria T2 Rudolph's Pediatrics, 23e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259588594 LK accesspediatrics.mhmedical.com/content.aspx?aid=1182928226 RD 2024/03/29 AB Hyperphenylalaninemia causes chronic toxic encephalopathy, depending on the timing, extent, and length of exposure to increased phenylalanine concentrations. Severe hyperphenylalaninemia leading to phenylketonuria (PKU) has a distinct role in the field of inherited metabolic disorders: PKU is the first genetic disease that could be treated exclusively by dietary manipulation and that could be entirely prevented by universal newborn screening and presymptomatic dietary intervention. This has had a huge impact on pediatric medicine, on the evolution of neonatal screening, and on the concept of gene-environment interaction. Genetic defects associated with hyperphenylalaninemia can be regarded as a strong risk factor for neurodisability, but the clinical outcome is more determined by the quality of metabolic treatment than by genetic variability.