Alpha-thalassemia - myelodysplastic syndrome (Orphanet_231401) can be described as follows. Alpha-thalassemia-myelodysplastic syndrome (ATMDS) is an acquired form of alpha-thalassemia (see this term) characterized by a myelodysplastic syndrome (MDS) or more rarely a myeloproliferative disease (MPD) associated with hemoglobin H disease (HbH; see these terms). Also known as: ATMDS, Acquired HbH disease, Acquired hemoglobin H disease.