Thalassemia is classified into two based on the globin gene defect: alpha-thalassemia (Hemoglobin Subunit Alpha 1: HBA1 and Hemoglobin Subunit Alpha 2: HBA2 genes) and beta-thalassemia (Hemoglobin Subunit Beta: HBB gene). This evidence concerns the gene HBA2 and alpha thalassemia spectrum.