Alpha-Globin Gene Deletion or Duplication [16124X]

Test Code
16124

CPT Codes
81269<br /> ** This test code is for non-New York patient testing. For New York patient testing, use test code 16125X**

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) tube

Minimum Volume
3 mL

Other Acceptable Specimens
Whole blood collected in: Sodium heparin (green-top), lithium heparin (green-top) or ACD solution B (yellow-top) • Amniotic fluid • Cultured cells • Chorionic villus sampling

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

Amniotic fluid (acceptable)
: 20 mL (min 5 mL) specimen stability is crucial. Store and ship room temperature immediately. Do not refrigerate or freeze.

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

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

Provide family history;
For prenatal diagnosis with a fetal specimen:
1) Parents must be documented carriers of one of the mutations tested
2) Maternal blood or DNA must be available
3) Contact the laboratory genetic counselor before submission

Provide clinical information (MCV, blood work, age, alpha globin mutations detected, ethnicity).
For other sample types please contact the laboratory.

Transport Temperature
Room temperature

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

All other samples

Room temperature: 8 days
Refrigerated: Unacceptable
Frozen: Unacceptable

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

Methodology
Capillary Electrophoresis • Multiplex 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: As needed; Report available: 14-21 days following set up

Limitations
This test does not identify whether a two-gene deletion is in cis (on the same chromosome) or trans (on opposite chromosomes). In the absence of a coexisting deletion on the opposite chromosome, this test can identify the presence of an extra alpha globin gene (alpha triplication).

Reference Range
See Laboratory Report

Clinical Significance
This test can be used to detect the presence or absence of large deletions in the HBA1 or HBA2 gene in patients or their family members suspected of having alpha thalassemia or who are carriers of alpha globin deletions. The assay can also be used in the prenatal diagnosis of alpha thalassemia. The assay does not determine the type or breakpoint of the rearrangement. This assay can be used instead of southern blot analysis to determine the total number of intact alpha globin genes.

Performing Laboratory
Quest Diagnostics Nichols Inst San Juan Capistrano
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130



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.