Monarch Disease Ontology entry MONDO_0019157 (myelodysplastic syndrome with ring sideroblasts) can be described as follows. Acquired idiopathic sideroblastic anemia is one of a group of disorders known as the myelodysplastic syndromes (MDS) characterized by ineffective haemopoiesis affecting one or more blood cell lineages (myeloid, erythroid or megakaryocytic) leading to peripheral blood cytopenias and an increased risk of developing leukemia. Acquired idiopathic sideroblastic anemia is now more commonly referred to as refractory anemia with ringed sideroblasts or the acronym RARS. Also known as: AISA, MDS with ring sideroblasts, MDS-RS, Pure sideroblastic Anaemia, Pure sideroblastic Anemia, RARS, acquired idiopathic sideroblastic anaemia, acquired idiopathic sideroblastic anemia.