Alpha-Globin Gene Sequencing

Test Code

16116

CPT Codes
81259

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.

Includes

If amniotic fluid or chorionic villi sampling (CVS) is received, then an additional charge will be added for cell culture work (CPT code(s): 88235) if not already ordered

Preferred Specimen

5 mL whole blood collected in an EDTA (lavender-top) tube

Minimum Volume

3 mL whole blood

Other Acceptable Specimens

Whole blood collected in: Sodium heparin (green-top) tube or ACD (yellow-top) tube • 10 mL amniotic fluid collected in a sterile plastic leak-proof container • 10 mg chorionic villi collected in a sterile tube filled with sterile culture media • Cultured cells collected in each of two separate sterile T-25 flasks, 75% confluent

Instructions

Do not hold specimen; forward to laboratory when specimen arrives.

Whole blood (preferred): Specimen stability is crucial. Store and ship room temperature immediately. Do not freeze.

For fetal testing:
1) Please call 1-866-GENE-INFO (1-866-436-3463) prior to submission; 2) Documentation of parental carrier status must be provided; 3) It is required that Maternal Cell Contamination Study, STR Analysis be ordered in conjunction with fetal testing. A separate tube of maternal blood (EDTA) is required for this test.

Amniotic fluid (acceptable): Normal collection procedure. Specimen stability is crucial. Store and ship at room temperature immediately. Do not refrigerate or freeze; forward to laboratory when sample arrives.

Amniocyte or Chorionic Villus (CVS) culture (acceptable): Two sterile T25 flasks, 75% confluent, filled with culture medium. Specimen stability is crucial. Store and ship at room temperature immediately. Do not refrigerate or freeze; forward to laboratory when cells arrive.

Dissected Chorionic Villus (CVS) biopsy (acceptable): 10-20 mg dissected chorionic villi collected in sterile tube, filled with sterile culture medium. Specimen stability is crucial. Store and ship at room temperature immediately. Do not refrigerate or freeze; forward to laboratory when sample arrives.

Transport Temperature

Room temperature

Specimen Stability

⁠⁠⁠⁠⁠⁠⁠Whole blood
Room temperature: 30 days
Refrigerated: 30 days
Frozen: 30 days

Amniotic fluid, chorionic villi, cultured cells
Room temperature: 48 hours
Refrigerated: Unacceptable
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Do not reject

Methodology
DNA Sequencing • Polymerase Chain Reaction (PCR)

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 FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Wed; Report available: Tues, 4 weeks following set up

Reference Range

See Laboratory Report

Clinical Significance

Alpha thalassemia is an inherited blood disorder characterized by a reduced or absent production of alpha globin. The majority of people who have alpha thalassemia trait or disease will have deletions of any number of the 4 alpha globin genes. A smaller percentage will have small deletions/duplications or missense variants.

This test identifies non-deletional variants in the alpha globin genes. It is the recommended first-tier test only if an alpha globin variant is identified on hemoglobin HPLC. It can also be used as a second-tier test for an individual for whom deletion testing is negative or doesn't completely explain the patient's clinical picture.

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.