[Molecular pathophysiology of sideroblastic anemia]

Sideroblastic anemias (SAs) are heterogeneous congenital and acquired disorders characterized by anemia and the presence of ring sideroblasts in bone marrow. Congenital sideroblastic anemia (CSA) is a rare disease caused by mutations in genes that are involved in heme biosynthesis, iron-sulfur [Fe-S] cluster biosynthesis, and mitochondrial protein synthesis. The most common form of CSA is X-linked sideroblastic anemia; it occurs because of mutations in the erythroid-specific δ-aminolevulinate synthase gene (ALAS2), which is the first enzyme of the heme biosynthesis pathway in erythroid cells. Additionally, SAs can occur after exposure to certain drugs or alcohol and with copper deficiency (secondary SA) ; they are also detected in association with myelodysplastic syndrome (idiopathic SA). Among all types of SAs, idiopathic SA is the most common form. This review encompasses the current understanding of the molecular pathophysiology of SA.