Alpha Globin Gene Sequencing, Varies
Use
This test is useful for diagnosing nondeletional alpha thalassemia in symptomatic individuals and for follow-up testing to an abnormal hemoglobin electrophoresis that identified an alpha-globin chain variant. Alpha-globin gene sequencing detects nondeletional alpha-thalassemia variants and other alpha-globin variants that can result in variable phenotypes, including erythrocytosis and chronic hemolytic anemia. It is especially indicated when there is a strong clinical suspicion of alpha thalassemia and the AGDD / Alpha Globin Cluster Locus Deletion/Duplication test is negative.
Special Instructions
Not provided.
Limitations
This assay does not detect large deletions or duplications within the alpha-globin genes, which account for most of the alpha-thalassemia alterations. Results should be interpreted in the context of hemoglobin electrophoresis, clinical findings, and family history. Rare genetic alterations may lead to false-negative or false-positive results. Additional testing may be necessary if results do not align with clinical expectations.
New York Approved
Methodology
Sanger
Biomarkers
HBA1, HBA2
Gene
LOINC Codes
- 87730-8 - HBA1 + HBA2 Full Mut Anl Bld/T Seq
- 69047-9 - Geneticist review
- 87730-8 - HBA1 + HBA2 Full Mut Anl Bld/T Seq
Result Turnaround Time
10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
4 mL
Minimum Volume
1 mL
Container
Preferred: Lavender top (EDTA). Acceptable: Yellow top (ACD), green top (sodium heparin)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in the original tube. Do not aliquot.
Storage Instructions
Refrigerate 30 days (preferred) / Ambient 14 days
Causes for Rejection
Moderately to severely clotted samples
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 30 days |