Sideroblastic anemia

anemia caused by defective heme metabolism, which leads to iron trapping inside the mitochondria

• 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)

  • Copper deficiency

  • Myelodysplastic syndrome

  • Malignancy

• CBC: microcytic anemia

• Serum iron studies

  • High ferritin

  • High iron

  • High transferrin saturation

  • Normal/low TIBC

• Peripheral blood smear

  • Basophilic stippling of RBCs

  • Normocytes/macrocytes (more common in acquired etiologies)

• Prussian blue staining of bone marrow: ringed sideroblasts

• Cessation of the offending agent

• Pyridoxine (B6) supplementation (a cofactor for δ-ALA synthase)