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Sickle cell anemia - Overview

Alternative Names

Anemia - sickle cell; Hemoglobin SS disease (Hb SS); Sickle cell disease

Definition of Sickle cell anemia:

Sickle cell anemia is a disease passed down through families in which red blood cells form an abnormal crescent shape. (Red blood cells are normally shaped like a disc.)

Causes, incidence, and risk factors:

Sickle cell anemia is caused by an abnormal type of hemoglobin called hemoglobin S. Hemoglobin is a protein inside red blood cells that carries oxygen. Hemoglobin S changes the shape of red blood cells, especially when the cells are exposed to low oxygen levels. The red blood cells become shaped like crescents or sickles.

The fragile, sickle-shaped cells deliver less oxygen to the body's tissues. They can also get stuck more easily in small blood vessels, and break into pieces that interupt healthy blood flow.

Sickle cell anemia is inherited from both parents. If you inherit the hemoglobin S gene from one parent and normal hemoglobin (A) from your other parent, you will have sickle cell trait. People with sickle cell trait do not have the symptoms of sickle cell anemia.

Sickle cell disease is much more common in people of African and Mediterranean descent. It is also seen in people from South and Central America, the Caribbean, and the Middle East.

Red blood cells, sickle cell

Red blood cells, normal

Red blood cells, multiple sickle cells

Red blood cells, sickle cells

Red blood cells, sickle and pappenheimer

Formed elements of blood

Blood cells

Reviewed last on: 2/28/2011
David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital.

References

Lee MT, Piomelli S, Granger S, et al. Stroke prevention trial in sickle cell anemia (STOP): extended follow-up and final results. Blood. 2006;108:847-852.

Brawley OW, Cornelius LJ, Edwards LR, Gamble VN, Green BL, Inturrisi C, et al. National Institutes of Health consensus development conference statement: hydroxyurea treatment for sickle cell disease. Ann Intern Med. 2008;148:932-938.

Geller AK, O'Connor MK. The sickle cell crisis: a dilemma in pain relief. Mayo Clin Proc. 2008;83:320-323.

Hebbel RP. Pathobiology of sickle cell disease. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone;2008:chap 42.

Saunthararajah Y, Vichinsky EP, Embury SH. Sickle cell disease. Clinical features and management. In: Hoffman R, Benz Jr. EJ, Shattil SS, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingston; 2008:chap 43.

U.S. Preventive Services Task Force. Screening for Sickle Cell Disease in Newborns: U.S. Preventive Services Task Force Recommendation Statement. Agency for Healthcare Research and Quality, Rockville, MD. Sep 2007:AHRQ Publication No. 07-05104-EF-2.

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