Myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematologic stem cell disorders characterized by ineffective hematopoiesis resulting in low blood counts, most commonly anemia, and a risk of progression to acute myeloid leukemia (AML; 601626). Blood smears and bone marrow biopsies show dysplastic changes in myeloid cells, with abnormal proliferation and differentiation of 1 or more lineages (erythroid, myeloid, megakaryocytic). MDS can be subdivided into several categories based on morphologic characteristics, such as low-grade refractory anemia (RA) or high-grade refractory anemia with excess blasts (RAEB). Bone marrow biopsies of some patients show ringed sideroblasts (RARS), which reflects abnormal iron staining in mitochondria surrounding the nucleus of erythrocyte progenitors (summary by Delhommeau et al., 2009 and Papaemmanuil et al., 2011).

OMIM