RT Book, Section A1 Ponka, Prem A1 Prchal, Josef T. A2 Kaushansky, Kenneth A2 Lichtman, Marshall A. A2 Prchal, Josef T. A2 Levi, Marcel M. A2 Press, Oliver W. A2 Burns, Linda J. A2 Caligiuri, Michael SR Print(0) ID 1121095397 T1 Polyclonal and Hereditary Sideroblastic Anemias T2 Williams Hematology, 9e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071833004 LK hemonc.mhmedical.com/content.aspx?aid=1121095397 RD 2024/04/24 AB SUMMARYSideroblastic anemias are characterized by the presence of ring sideroblasts in the marrow. These cells are erythroid precursors that have accumulated abnormal amounts of mitochondrial iron. A variety of abnormalities of porphyrin metabolism in affected erythroid cells have been documented. Hereditary sideroblastic anemias are usually X linked, as the result of mutations in the erythroid form of 5-aminolevulinic acid synthase. Inherited autosomal and mitochondrial forms are seen, occasionally. Acquired sideroblastic anemias can occur as a result of the ingestion of drugs, alcohol, or toxins such as lead or zinc, or copper deficiency. Patients with acquired sideroblastic macrocytic anemia and variable degrees of thrombocytopenia and leukopenia from copper deficiency have been recognized more frequently; the hematologic abnormalities typically resolve after copper replacement. Ring sideroblasts are also a feature of myelodysplastic neoplasms, and are discussed in Chap. 87. Some patients with sideroblastic anemia may respond to pharmacologic doses of pyridoxine. Iron loading is common in the sideroblastic anemias and can be treated by phlebotomy when the anemia is mild or with iron chelators (Chap. 43) when it is more severe.