Key points to remember about sideroblastic anemia for the USMLE

-Sideroblastic anemia results from hereditary (X-linked) or acquired disorder of heme synthesis.

-It is a microcytic hypochromic anemia with a high RDW (red cell distribution width) Same as iron deficiency anemia.

-Iron studies will distinguish the two. In sideroblastic anemia serum iron, serum ferritin and transferrin saturation are increased.

-The impaired synthesis of heme leads to retention of iron in the mitochondria. The nucleated RBC's show aggregation of iron in the mitochondria and has a perinuclear distribution. These cells are called ringed sideroblasts, which are characteristically seen in sideroblastic anemia.

-Severity can be mild or severe enough to need frequent transfusions.

-Treatment: Pyridoxine helps in some rare inherited cases but manu need periodic transfusions. Stem cell transplantation has been used to treat children who are dependent on blood transfusion.