Associated disorders

The PAH gene is associated with autosomal recessive hyperphenylalaninemia (HPA), which includes the spectrum of phenylketonuria (PKU), non-PKU hyperphenylalaninemia (non-PKU HPA) and variant PKU (MedGen UID: 19244).

Order single gene


Order this gene as a single gene test.

Order a test

Invitae tests that include this gene:

An estimated >97% of cases of hyperphenylalaninemia are due to pathogenic variants in the PAH gene.

The PAH gene encodes the phenylalanine hydroxylase (PAH) enzyme. PAH catalyzes the conversion of phenylalanine to tyrosine, using the cofactor tetrahydrobiopterin (BH4). This reaction is critical for the production of tyrosine as well as downstream metabolites such as melanin and the catecholamines, dopamine, norepinephrine, and epinephrine.

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
PAH NM_000277.1