acquired or hereditary anemia marked by sideroblasts: bone marrow cells with large mitochondrial deposits of insoluble iron due to defective heme synthesis, leading to ineffective erythropoiesis.
A myelodysplastic syndrome characterized mainly by dysplasia of the erythroid series. Refractory anemia is uncommon. It is primarily a disease of older adults. The median survival exceeds 5 years. (WHO, 2001) -- 2003