PAH

Function

Catalyzes the hydroxylation of L-phenylalanine to L-tyrosine.

Involvement in disease

Phenylketonuria

PKU

Autosomal recessive inborn error of phenylalanine metabolism, due to severe phenylalanine hydroxylase deficiency. It is characterized by blood concentrations of phenylalanine persistently above 1200 mumol (normal concentration 100 mumol) which usually causes mental retardation (unless low phenylalanine diet is introduced early in life). They tend to have light pigmentation, rashes similar to eczema, epilepsy, extreme hyperactivity, psychotic states and an unpleasant 'mousy' odor.

None

The disease is caused by variants affecting the gene represented in this entry.

Non-phenylketonuria hyperphenylalaninemia

Non-PKU HPA

Mild form of phenylalanine hydroxylase deficiency characterized by phenylalanine levels persistently below 600 mumol, which allows normal intellectual and behavioral development without treatment. Non-PKU HPA is usually caused by the combined effect of a mild hyperphenylalaninemia mutation and a severe one.

None

The disease is caused by variants affecting the gene represented in this entry.

Hyperphenylalaninemia

HPA

Mildest form of phenylalanine hydroxylase deficiency.

None

The disease is caused by variants affecting the gene represented in this entry.

Pathway

Amino-acid degradation; L-phenylalanine degradation; acetoacetate and fumarate from L-phenylalanine: step 1/6.

Post-translational modifications

Phosphorylation at Ser-16 increases basal activity and facilitates activation by the substrate phenylalanine.

Sequence similarities

Belongs to the biopterin-dependent aromatic amino acid hydroxylase family.

Alternative names

• Phenylalanine-4-hydroxylase
• PAH
• Phe-4-monooxygenase
• PAH

Database links

• entrezGene:5053
• omim:612349
• swissprot:P00439

Target type

Proteins

Molecular weight

51862Da