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 well known since it is one of several genetic diseases that babies are screened for at birth. Neonatal screening for PKU is critical since immediate changes in the diet can avert critical damage. The diet is designed to limit the intake of phenylalanine, as well as supplementing with tyrosine, and can reduce the severity of the symptoms allowing those with the disease to lead relatively normal lives.