Phenylketonuria (PKU) Gene Sequencing

Test Code

16152

CPT Codes
81406

Physician Attestation of Informed Consent

This germline genetic test requires physician attestation that patient consent has been received if ordering medical facility is located in AK, DE, FL, GA, IA, MA, MN, NV, NJ, NY, OR, SD or VT or test is performed in MA.

Preferred Specimen

5 mL whole blood collected in an EDTA (lavender-top or royal blue-top), ACD (yellow-top) or sodium or lithium heparin (green-top) tube

Minimum Volume

3 mL whole blood • 10 mL amniotic fluid

Other Acceptable Specimens

Cultured cells from amniotic fluid or cultured cells from CVS collected T-25 Flask • 20 mL amniotic fluid collected in leak-proof 15 mL conical tubes

Instructions

Whole blood (preferred): Normal phlebotomy procedure. Specimen stability is crucial. Store and ship room temperature immediately. Do not freeze. For prenatal diagnosis parental results must be available. Contact the laboratory genetic counselor before submission.

Amniotic fluid: Normal collection procedure. Specimen stability is crucial. Store and ship room temperature immediately. Do not refrigerate or freeze.

Amniocyte culture: Sterile T25 flask, filled with culture medium. Specimen stability is crucial. Store and ship room temperature. Do not refrigerate or freeze.

Dissected chorionic villi (CVS) biopsy: 10-20 mg dissected CVS collected in a sterile tube filled with sterile culture medium. Specimen stability is crucial. Store and ship room temperature immediately. Do not refrigerate or freeze.

Transport Temperature

Room temperature

Specimen Stability

Whole blood (preferred)
Room temperature: 8 days
Refrigerated: 8 days
Frozen: Unacceptable

CVS or amniotic fluid
Room temperature: 48 hours
Refrigerated: Unacceptable
Frozen: Unacceptable

Methodology
Next Generation Sequencing

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Wed a.m.; Report available: 30 days

Limitations

This test will identify greater than 99% of mutations. Large rearrangements (deletions/insertions) are rare and not detectable by this test method. If no mutation is found by the testing procedure, it does not mean that the risk of carrying or developing PKU is not present. It simply means that this risk is significantly reduced.

Reference Range

See Laboratory Report

Clinical Significance

1. To identify disease-causing variants in individuals affected with PKU.
2. To identify carriers in high risk ethnic groups or people with a positive family history.
3. Prenatal diagnosis of PKU.

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.