Alpha Globin Genotype, Alpha Thal, Alpha Thalassemia
Alpha Globin Genotype, Alpha Thal, Alpha Thalassemia
Test Codes
EPIC: Order Reference Lab Send out for Miscellaneous test(LAB848), Beaker: Ref lab Misc, LabCorp: 484278
Department
Send Outs
Instructions
This test is not included in the Corewell Health Laboratory testing formulary; however, the Laboratory can facilitate specimen collection.
- This test is usually performed after hemoglobin electrophoresis and measurement of HbA2 to rule out beta-thalassemia.
- This test will be billed to the patient’s insurance. If not covered by insurance, the patient is responsible for the full cost of testing.
- Order test as a Reference Lab Send Out for Miscellaneous Test (LAB848)).
- Please call the Send Outs Laboratory before collecting an amniotic fluid specimen. All amniotic fluid specimens must be accompanied by a maternal blood specimen. This is necessary for maternal cell contamination testing. Obtain specimen during 14th – 17th week of gestation.
- After hours collection: Specimens may be drawn and ordered.
Specimen Collection Criteria
Blood: Two (2) Lavender-top EDTA tube. (Minimum: 3.0 mL)
Rejection Criteria
- Frozen specimens
- Hemolyzed specimens
- Specimens not collected or processed as indicated.
In-Lab Processing
Maintain blood specimens at room temperature (20-26°C or 68-78.8°F) or amniotic fluid specimens refrigerated (2-8°C or 36-46°F) until transport.
Transport: 7.0 mL whole blood, at room temperature (20-26°C or 68-78.8°F), or 10.0 mL amniotic fluid, refrigerated (2-8°C or 36-46°F). (Minimum: 3.0 mL whole blood or 5.0 mL amniotic fluid.)
Laboratory
Sent to LabCorp Integrated Genetic, Westborough, MA.
Performed
Results available in 9-12 days.
Reference Range
By report.
Test Methodology
Dosage Analysis by Polymerase Chain Reaction (PCR)/Multiplex Ligation-Dependent Probe Amplification (MLPA).
Interpretation
By report.
Hemoglobin electrophoresis should usually be done prior to this test to exclude other diagnoses or to identify non-deletion types of alpha-thalassemia.
This test is not useful for diagnosis / confirmation of beta-thalassemia or hemoglobinopathies.
Clinical Disease
Alpha-thalassemia occurs in all ethnic groups but is especially common in African Americans (30%) and in Southeast Asians (at least 25%). It is also found frequently in individuals of Mid-Eastern and Indian ancestry. While deletion type of alpha-thalassemia is much more common, both non-deletion type and deletion type have been described in each affected population.
Alpha-thalassemia is caused by decreased synthesis of alpha-globin chains. Four alpha-globin genes are normally present (two on each chromosome 16). One, two, three, or four alpha-globin genes may be deleted or contain mutations in patients with alpha-thalassemia, with more than 30 alpha-haplotypes having been described. Phenotypically, these result in four categories of disease expression:
- Deletion of one alpha-chain results in a normal phenotype (i.e., no CBC abnormalities).
- Alpha-thalassemia minor, with mild hematologic changes, but no major clinical difficulties, occurs with deletion of two alpha genes.
- Hemoglobin H disease, which is extremely variable but usually includes anemia due to hemolysis, jaundice, and hepatosplenomegaly (deletion of three alpha genes)
- Hydrops fetalis with deletion of all four alpha-globin genes variably results in utero demise.
CPT Codes
81257
Contacts
Send Outs Laboratory – RO
248-551-9045
Name: Send Outs Laboratory – RO
Location:
Phone: 248-551-9045
Last Updated
8/12/2025
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