Monarch Disease Ontology entry MONDO_0010328 (alpha-thalassemia-myelodysplastic syndrome) (ATMDS) is an acquired form of alpha-thalassemia characterized by a myelodysplastic syndrome (MDS) or more rarely a myeloproliferative disease (MPD) associated with hemoglobin H disease (HbH). Also known as: ATMDS, acquired HbH disease, acquired haemoglobin H disease, acquired hemoglobin H disease, alpha-thalassemia myelodysplasia syndrome, somatic.