Phenylketonuria : PAH Sequencing

Test Information

PAH sequencing is a molecular test used to identify variants in the gene associated with Phenylketonuria.

Turnaround Time

2 weeks

CPT Code(s)

81406

Cost

$1,000

Genes

Clinical Information

Phenylketonuria (PKU) is caused by a deficiency of phenylalanine hydroxylase. This deficiency leads to an elevation in the levels of phenylalanine in the brain, blood and other tissues. This condition is treatable with a life long diet low in phenylalanine and is part of all state newborn screening programs. Individuals with PKU have mutations in the PAH gene.

Indications

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Methodology

Sanger Sequencing

Detection

Sequencing of the gene will detect mutations in 99% of individuals with PKU.

Specimen Requirements

5 to 7 ml of peripheral blood collected in an EDTA (lavender top) tube is the preferred specimen type. The minimal blood needed for reliable DNA isolation is 3 ml. Extracted DNA, dried blood spots, and saliva are also accepted for this test.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Molecular Testing, Newborn Screening Follow-Up, Sanger Sequencing
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Meet Makayla Gunn

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