HBA2 and Alpha-thalassemia: In contrast, alpha‐thalassemia is mainly due −α3·7 and −α4·2 deletions in the alpha‐globin genes: hemoglobin subunit alpha 1 (HBA1; OMIM 141800; NM_000558.5) or hemoglobin subunit alpha 2 (HBA2; OMIM 141850; NM_000517.6) (De Silva et al., 2000).