Phenylketonuria
Phenylketonuria (PKU) is an autosomal recessive genetic disorder characterized by a deficiency in the hepatic enzyme phenylalanine hydroxylase.[1]:541 This enzyme is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine. When PAH is deficient, phenylalanine accumulates and is converted into phenylpyruvate (also known as phenylketone), which is detected in the urine.[citation needed].
Left untreated, this condition can cause problems with brain development, leading to progressive mental retardation, brain damage, and seizures. Historically, PKU has been treated with a low-phe diet. Research now has proved that diet alone may not be enough to prevent the negative effects of Phe levels. Optimal treatment involves lowering blood Phe levels to a safe range and monitoring diet and cognitive development. Lowering of Phe levels to a safe range may be achieved by combining a low phe-diet with medication. There is currently no cure for this disease. PKU is generally detected through newborn screening and diagnosed by a geneticist. PKU clinics around the world provide integrative care for PKU patients to optimize phe levels, dietary intake and cognitive outcomes.