Description:

The phenylalanine hydroxylase gene (PAH) located on chromosome 12q and expressed in liver, is responsible for phenylketonuria (PKU) or hyperphenylalaninemia. PKU is one of the most common inborn errors of amino acid metabolism, with an incidence of 1 in 10,000 in Caucasians of European descent. The biochemical phenotype of PAH deficiency can vary from mild hyperphenylalaninemia (MHP) to classical PKU. More than 400 point mutations in the PAH gene have been reported, with the most prevalent 7 mutations accounting for less than 50% of the mutant alleles in all ethnic groups. In order to provide a more comprehensive molecular analysis, the entire PAH gene is sequenced.

Reasons for Referral:

• To confirm the diagnosis of PAH deficiency.
• Carrier testing

Testing Methodology:

The exons and flanking intron regions of PAH gene are PCR amplified and sequenced.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 14 cc; Child: 6 cc; Infant: 2-3 cc

Turnaround Time:

Index: 4 weeks
Known Familial Mutation: 2 weeks

CPT Codes and Prices:

Index: 83904x24, 83898x12, 83912, 83891
Known Familial Mutation: 83904x4, 83898x2, 83912, 83891, 83894x2

Shipping Information

Forms:

>> Gene Sequencing Requisition

Test Codes:

Index: 3135
Known Familial Mutation: 3136

Medical Genetics Laboratories
Baylor College of Medicine · Houston, TX 77030
Phone: 1-800-411-GENE · Fax: 713-798-6584
E-mail: