hemoglobin H disease (MONDO_0013512) is alpha thalassemia caused by variation in three of the four copies of the alpha hemoglobin genes (e.g., large deletion in HBA1 and HBA2 genes in trans with a variant in either HBA1 or HBA2). Also known as: Alpha-thalassemia intermedia, HBA1;HBA2 digenic triallelic hemoglobin H disease, HBH, HbH, HbH disease, alpha thalassemia, haemoglobin H type, alpha thalassemia, hemoglobin H type, alpha-thalassemia intermedia.