Phenylketonuria

Phenylketouria (PKU) is a metabolic disease due to the loss of an enzyme phenylalanine hydroxylase (PAH) that is required to metabolise the amino acid phenylalanine to tyrosine. The impact of this deficiency can be severe causing mental retardation and organ damage. It is commonly known since it is one of several genetic diseases that babies are screened for at birth. Neonatal screening is critical since changes in the diet, limiting the intake of phenylalanine, can reduce the severity of the symptoms.