Alpha Globin (HBA1 and HBA2) Deletion/Duplication

Casandra

Casandra Test Code AR77099Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2011622CPT Code 81269

Alpha Globin (HBA1 and HBA2) Deletion/Duplication

Also known as: HBA DD

Clinical Use

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Use

This test is used for the confirmation of suspected alpha thalassemia or alpha thalassemia trait. It detects common, rare, and novel deletions or duplications in the alpha globin gene cluster, which can result in alpha thalassemia, a condition that affects the synthesis of the hemoglobin alpha-chain. This test is particularly suitable for detecting large deletions or duplications associated with different forms of alpha thalassemia, leading to conditions like Hemoglobin H disease and Hb Bart hydrops fetalis syndrome.

Special Instructions

Informed consent for genetic testing is required for New York state patients. Medical management should be based on clinical findings and family history. If clinical findings suggest potential alpha-thalassemia, further alpha globin gene sequencing may be considered. Genetic consultation is recommended, and carrier screening for relatives may be appropriate.

Limitations

This test is specifically designed to detect large deletions or duplications within the alpha globin gene cluster. It does not detect single exon deletions/duplications based on rearrangement breakpoints, and specific breakpoints of large deletions/duplications cannot be determined. As such, similar-sized mutations may not be distinguishable. Nondeletional mutations within the coding or regulatory regions of the alpha globin cluster genes are not assessed. Errors may occur due to rare sequence variations and individuals carrying both a deletion and a duplication may appear normal.

Test Details

New York Approved