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thalassemia

In 1925, Cooley described a group of children with severe anemia, skeletal & facial abnormalities, splenomegaly, erythrocytes with bizarre morphology, & circulating nucleated red cells. Thus originated the term Cooley's anemia for beta thalassemia major. Since these children were of Italian or Greek ancestry, the term thalassemia (the sea in the blood) was adopted. The thalassemias are inherited disorders characterized by hypochromic, microcytic anemia secondary to decreased synthesis of one of the globin chains. Epidemiology: - Mediterranean: Italy, Greece, - Middle east: Arabian peninsula, Turkey, Iran - Asia: India, Thailand, Cambodia, southern China - immigrants from these areas Pathology: - imbalance in globin chain synthesis results in precipitation of hemoglobin in maturing red cells & aggregation into protein inclusions (Heinz bodies) with membrane changes & hemolysis - marked deficiency in alpha-globin or beta-globin synthesis results in clinically significant reduction of hemoglobin A synthesis & ineffective erythropoiesis Genetics: - family history of congenital anemia Laboratory: 1) complete blood count a) anemia minimal - RBC count may be increased or normal - > 5 x 10E12/L (Fe deficiency < 5 x 10E12/L) b) RDW < 16 (Fe deficiency > 16) c) MCV may be very low (microcytosis) 2) peripheral smear: target cells 3) hemoglobin electrophoresis (see specific thalassemia) 4) see ARUP consult [4] Differential diagnosis: - iron-deficiency anemia (see beta-thalassemia) Complications: - iron overload requiring chelation therapy Management: 1) supportive - folate supplementation - avoid iron supplementation [3] 2) splenectomy for transfusion-dependent thalassemia [3] 3) bone marrow transplant for severe thalassemia [3]

Interactions

disease interactions

Specific

alpha thalassemia beta thalassemia

General

hemoglobinopathy hemolytic anemia microcytic anemia

References

  1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 585-86
  2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 409
  3. Medical Knowledge Self Assessment Program (MKSAP) 14, 16, 17, 18, 19. American College of Physicians, Philadelphia 2006, 2012, 2015, 2018, 2022
  4. ARUP Consult: Thalassemias The Physician's Guide to Laboratory Test Selection & Interpretation https://arupconsult.com/content/thalassemias
  5. Cunningham MJ. Update on thalassemia: clinical care and complications. Hematol Oncol Clin North Am. 2010 Feb;24(1):215-27 PMID: 20113904
  6. Peters M, Heijboer H, Smiers F, Giordano PC. Diagnosis and management of thalassaemia. BMJ. 2012 Jan 25;344:e228. PMID: 22277544
  7. Higgs DR, Engel JD, Stamatoyannopoulos G. Thalassaemia. Lancet. 2012 Jan 28;379(9813):373-83. PMID: 21908035
  8. Brancaleoni V, Di Pierro E, Motta I, Cappellini MD. Laboratory diagnosis of thalassemia. Int J Lab Hematol. 2016 May;38 Suppl 1:32-40. Review. PMID: 27183541
  9. Learning About Thalassemia http://www.genome.gov/page.cfm?pageID=10001221