Test Catalog

Test ID: WBDDR    
Beta-Globin Cluster Locus Deletion/Duplication, Blood

Useful For Suggests clinical disorders or settings where the test may be helpful

Determining the etiology of hereditary persistence of fetal hemoglobin (HPFH) or delta-beta thalassemia


Diagnosing less common causes of beta-thalassemia; these large deletional beta thalassemia alterations result in elevated hemoglobin (Hb) A2 and usually have slightly elevated HbF levels


Distinguishing homozygous HbS disease from a compound heterozygous HbS/large beta-globin cluster deletion disorder (ie, HbS/beta zero thalassemia, HbS/delta beta zero thalassemia, HbS/HPFH, HbS/gamma-delta-beta-thalassemia)


Diagnosing complex thalassemias where the beta-globin gene and 1 or more of the other genes in the beta-globin cluster have been deleted


Evaluating and classifying unexplained increased HbF percentages


Evaluating microcytic neonatal anemia


Evaluating unexplained long standing microcytosis in the setting of normal iron studies and negative alpha thalassemia testing/normal Hb A2 percentages


Confirming gene fusion hemoglobin variants such as Hb Lepore and Hb P-Nilotic


Confirming homozygosity vs hemizygosity of alterations in the beta-like genes (HBB, HBD, HBG1, HBG2)


This test is not useful for diagnosis or confirmation of alpha thalassemia, the most common beta thalassemias, or hemoglobin variants. It also does not detect nondeletional hereditary persistence of fetal hemoglobin.


This test is recommended to identify a variety of conditions involving large deletions or duplications within the beta-globin gene cluster locus region including:

-Identifying large deletions causing increased hemoglobin (Hb) F levels such as hereditary persistence of fetal hemoglobin (HPFH), delta-beta thalassemias, and gamma-delta-beta thalassemia

-Identifying beta thalassemia conditions in cases where beta gene sequencing did not find a beta thalassemia genetic variant

-Confirming gene fusion hemoglobin variants such as Hb Lepore and Hb P-Nilotic

-Investigating newborns with unexplained microcytic anemia that is suspected to be caused by epsilon-gamma-delta-beta thalassemia

-Confirming homozygosity vs hemizygosity of genetic variants in the beta-like genes (HBB, HBD, HBG1, HBG2)

-Investigating individuals older than 12 months of age with unexplained microcytosis and normal hemoglobin electrophoresis for whom more common causes of microcytosis such as iron deficiency and alpha thalassemia have been excluded

Method Name A short description of the method used to perform the test

Only orderable as a reflex. For more information see:

-HAEV1 / Hemolytic Anemia Evaluation, Blood

-HBEL1 / Hemoglobin Electrophoresis Evaluation, Blood

-MEV1 / Methemoglobinemia Evaluation, Blood

-REVE1 / Erythrocytosis Evaluation, Whole Blood

-THEV1 / Thalassemia and Hemoglobinopathy Evaluation, Blood and Serum


Polymerase Chain Reaction (PCR) Analysis/Multiplex Ligation-Dependent Probe Amplification (MLPA)

NY State Available Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name Lists a shorter or abbreviated version of the Published Name for a test

Beta Globin Cluster Locus Del/Dup,B

Aliases Lists additional common names for a test, as an aid in searching

MLPA beta globin cluster locus
Beta globin cluster locus deletion/duplication
Beta globin deletion
Beta thalassemia deletion
Beta globin complex deletions
Beta cluster del/dup