Iron deficiency (associated with high RDW and low MCH):
(1) inadequate intake
(2) increased blood loss
(3) malabsorption (celiac disease, Crohn's disease, etc)
(4) hereditary defect in iron transport or utilization (atransferrinemia, other)
(5) autoantibody against the transferrin receptor
Hemoglobinopathy:
(1) alpha or beta thalassemia
(2) sickle-thalassemia
(3) hemoglobin E
Anemia of chronic disease
Hereditary sideroblastic anemia
(1) X-linked
(2) autosomal recessive
(3) associated with mitochondrial DNA deletion or mutation
Premalignant or malignant disease
(1) myelodysplasia (with or without sideroblasts)
(2) therapy-related myeloid neoplasms
(3) Castleman's disease
Other causes of acquired sideroblastic anemia:
(1) lead poisoning
(2) arsenic poisoning
(3) aluminum poisoning
(4) copper deficiency
(5) alcohol
(6) drugs: isoniazid (INH), chloramphenicol, cycloserine, penicillamine, azathioprine
Associated with mitochondrial DNA deletions or mutations:
(1) Pearson's marrow-pancreas syndrome
