Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine.[2] Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorder. It may also result in a musty smell and lighter skin. Babies born to mothers who have poorly treated PKU may have heart problems, a small head, and low birth weight.[1]
Phenylketonuria is a genetic disorder inherited from a person's parents. It is due to mutations in the PAH gene which results in low levels of the enzyme phenylalanine hydroxylase. This results in the build up of dietary phenylalanine to potentially toxic levels. It is autosomal recessive meaning that both copies of the gene must be mutated for the condition to develop. There are two main types, classic PKU and variant PKU, depending on if any enzyme function remains. Those with one copy of a mutated gene typically do not have symptoms.[1] Many countries have newborn screening programs for the disease.
