- Description: anemia caused by defective heme metabolism, which leads to iron trapping inside the mitochondria
 - Etiology
- Inherited: X-linked sideroblastic anemia due to a δ-ALA-synthase gene defect
 - Acquired
- Vitamin B6 deficiency
 - Lead poisoning
 - Alcohol use disorder
 - Drugs (e.g., chloramphenicol, isoniazid, linezolid)
 
 
 - Diagnostics
- CBC: microcytic anemia
- Serum iron studies
 - High ferritin
 - High iron
 - High transferrin saturation
 - Normal/low TIBC
 
 - Peripheral blood smear
- Basophilic stippling of RBCs
 
 - Prussian blue staining of bone marrow: ringed sideroblasts



 
 - CBC: microcytic anemia