TY - CHAP M1 - Book, Section TI - Polyclonal and Hereditary Sideroblastic Anemias A1 - Ponka, Prem A1 - Hamdi, Amel A1 - Prchal, Josef T. A2 - Kaushansky, Kenneth A2 - Prchal, Josef T. A2 - Burns, Linda J. A2 - Lichtman, Marshall A. A2 - Levi, Marcel A2 - Linch, David C. Y1 - 2021 N1 - T2 - Williams Hematology, 10e 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 copper deficiency or the ingestion of drugs, alcohol, or toxins such as lead or zinc. Patients with acquired sideroblastic macrocytic anemia and variable degrees of thrombocytopenia and leukopenia caused by copper deficiency have been recognized more frequently; the hematologic abnormalities typically resolve after copper replacement. Ring sideroblasts are also a feature of myelodysplastic neoplasms, which are discussed in Chap. 86. 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. 44) when it is more severe. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1180483436 ER -