HBA2 and alpha thalassemia spectrum: The pathogenic cause of α‐thalassemia contains deletions or mutations that eliminate one or both α‐globin genes (HBA1 and HBA2; OMIM: 141800 and 141850) from the influenced chromosome 16 (Zeng & Huang, 1985), and can be subdivided into α0‐thalassemia (the expression of two α‐globin genes on one allele is absent) and α+‐thalassemia (the expression of a single α‐globin gene is reduced or absent).