A carrier does not display any symptoms of the disease because the carrier's liver produces normal quantities of the PAH enzyme.
In more detail, PKU mutations can involve many different types of changes, such as deletions and insertions, in the DNA of the gene that codes for the PAH enzyme.
Mutations in the PAH gene prevent the liver from producing adequate levels of the PAH enzyme needed to break down phenylalanine.
Phenylketonuria (PKU) is a rare metabolic disorder caused by a deficiency in the production of the hepatic (liver) enzyme phenylalanine hydroxylase (PAH).
Subsequent diagnostic procedures (called mutation analysis and genotype determination) can actually identify the specific types of PAH gene mutations inherited by PKU infants.
The normal PAH gene is dominant to recessive PKU mutations.
The PAH gene and its PKU mutations are found on chromosome 12 in the human genome.
This family contains the paired amphipathic helix (PAH) repeat.
This is the only role of PAH in the body.