Alpha Globin Gene Sequencing, Varies

Casandra

Casandra Test Code MC67939Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID WASEQCPT Code 81259

Alpha Globin Gene Sequencing, Varies

Clinical Use

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

This test is used as a second-tier evaluation in the determination of alpha-thalassemia carrier status, hemoglobin H disease confirmation, and alpha-globin variant identification. Confirmatory hemoglobin electrophoresis evaluation is recommended before proceeding with alpha-globin gene sequencing. Not the preferred first-tier molecular test for alpha thalassemia carrier screening or diagnosis.

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.

Test Details

New York Approved