Sickle cell disease (also known as hemoglobin S disease) is a group of disorders that affect hemoglobin — the part of a red blood cell that delivers oxygen throughout the body. The disease gets its name from abnormally shaped red blood cells caused by abnormal hemoglobin molecules.
Symptoms of sickle cell disease usually begin in early childhood, and can include:
- Low red blood cell count, also known as anemia.
- Repeated infections.
- Periodic episodes of pain.
Intensity of symptoms varies from one person to another. Some people have very mild symptoms; others may be hospitalized for serious complications from pain and infections.
The symptoms are caused by the misshapen red blood cells — when the red blood cells take on the sickle (crescent) shape, they break down prematurely. This leads to anemia. Anemia comes with its own list of side effects, including shortness of breath, fatigue, and delayed growth/development in children. The rapid breakdown of red blood cells can also cause a yellowing of the eyes and skin — signs of jaundice. The periodic episodes of pain are also caused by the sickled cells. These stiff and inflexible warped blood cells can get stuck in small blood vessels, blocking blood flow to tissues and organs. Organ damage is often seen in the lungs, kidneys, spleen, and brain. High blood pressure in the blood vessels that supply the lungs is a serious complication seen in approximately one third of all adults with sickle cell disease. Pulmonary hypertension can lead to heart failure.
Sickle cell disease is seen in millions of people around the world. It is most commonly seen in the following groups:
- People of African descent
- People of Mediterranean descent (Greek, Turkish, Italian)
- People from the Arabian peninsula
- People of Indian descent
- People from Spanish-speaking regions in South America, Central America, and the Caribbean
In the United States, sickle cell disease is the most common inherited blood disorder. It affects as many as eighty thousand Americans. The condition is inherited in an autosomal recessive pattern — two copies of the gene are altered. Most often, the parents of a person with sickle cell disease each carry one copy of the altered gene without showing symptoms themselves.