Congenital sideroblastic anemias: iron and heme lost in mitochondrial translation.

The congenital sideroblastic anemias (CSAs) are an uncommon, diverse class of inherited hematopoietic disorders characterized by pathological deposition of iron in the mitochondria of erythroid precursors. In recent years, the genetic causes of several clinically distinctive forms of CSA have been elucidated, which has revealed common themes in their pathogenesis. In particular, most, if not all, can be attributed to disordered mitochondrial heme synthesis, iron-sulfur cluster biogenesis, or pathways related to mitochondrial protein synthesis. This review summarizes the clinical features, molecular genetics, and pathophysiology of each of the CSAs in the context of these pathways.