Sideroblastic anemia is a disorder of impaired heme synthesis in which red blood cell precursors fail to incorporate iron into protoporphyrin IX to form functional heme, despite iron uptake into mitochondria, resulting in dysfunctional, iron-laden erythroid cells and ineffective erythropoiesis. The condition arises either congenitally (most commonly X-linked, via mutations in the ALAS2 gene encoding delta-ALA synthase, the enzyme catalyzing the first step of the multi-step mitochondrial-and-cytosolic heme biosynthesis pathway) or through acquired causes (vitamin B6 deficiency, alcohol-induced mitochondrial damage, lead poisoning) that disrupt one or more enzymes in that pathway, distinguishing it within hematology from other iron-overload disorders such as hemochromatosis by its underlying defect in heme synthesis rather than iron absorption/regulation.
Sideroblastic anemia is a disorder of impaired heme synthesis in which red blood cell precursors fail to incorporate iron into protoporphyrin IX to form functional heme, despite iron uptake into mito…