Useful For

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.