How is phenylketonuria spread?

Phenylketonuria (PKU) is an inherited metabolic disorder that is caused by a mutation in the gene that codes for the enzyme phenylalanine hydroxylase (PAH). This enzyme is responsible for converting the amino acid phenylalanine into tyrosine. In people with PKU, the PAH enzyme is either deficient or completely absent, which leads to a build-up of phenylalanine in the blood and urine.

PKU is inherited in an autosomal recessive pattern, which means that both parents must carry the mutated gene in order for a child to be affected. If both parents are carriers, there is a 25% chance that each of their children will have PKU.

PKU is not spread through contact with an affected individual. It is a genetic disorder that is present from birth.