Sideroblastic anemia. Presence of anemia + ringed sideroblasts. Hypochromic, BIMODAL RBC population. +/- Pappenheimer bodies (iron). Increased iron stores in BM. All iron studies are elevated (but distinguish from hemochromocytosis because SA has low hgb and low MCV). CAUSES: ACQUIRED = RARS, meds, alcohol, Pearson syndrome and low copper. VAST MAJORITY HAVE CLONAL DEFECT. MACROCYTIC. >15% RS. INHERITED = rare, X-linked. ALAS2 gene. MICROCYTIC. Can try giving a ton of B6.