pku definition
Definition. Phenylketonuria (fen-ul-ke-toe-NU-re-uh), also called PKU, is a rare inherited disorder that causes an amino acid called phenylalanine to build up in your body.PKU is caused by a defect in the gene that helps create the enzyme needed to break down phenylalanine.Without the enzyme necessary to process phenylalanine, a dangerous buildup can develop when a person with PKU eats foods that are high in protein. This can eventually lead to serious health problems.KU is caused by a defect in the gene that helps create the enzyme needed to break down phenylalanine. Without the enzyme necessary to process phenylalanine, a dangerous buildup can develop when a person with PKU eats foods that are high in protein.