Alpha-Globin Gene Deletion or Duplication [16124X]

Test Code
16124

CPT Codes
81269<br /> **This test code is not available for 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 whole blood • 10 mg chorionic villi

Other Acceptable Specimens
Whole blood collected in: Sodium heparin (green-top), lithium heparin (green-top) or ACD solution B (yellow-top) • Amniotic fluid • Amniocyte cultured cells • 20 mg chorionic villus sampling

Instructions
Whole blood: Normal phlebotomy procedure. Specimen stability is crucial. Store and ship at room temperature immediately. Glass tubes should not be shipped frozen.

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

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

Dissected chorionic villi (CVS) biopsy: 10-20 mg dissected CVS 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.

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
Room temperature: 30 days
Refrigerated: 30 days
Frozen: 30 days

All other samples

Room temperature: 8 days
Refrigerated: Unacceptable
Frozen: Unacceptable

Methodology
Capillary Electrophoresis • Multiplex PCR

Setup Schedule
Set up: Tues; Report available: 2-3 weeks 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.