Sickle cell anemia is a painful, inherited condition in which the red blood cells become abnormally shaped. It may lead to pain or a number of other serious complications including stroke, life–threatening infection or end-organ damage.Red blood cells transport vital oxygen to the limbs and organs. These cells are normally disc–shaped. In people with sickle cell anemia, a large number of these red blood cells become sickle- or crescent–shaped.
Hemoglobin, a protein molecule present in all red blood cells, is responsible for transporting oxygen from the lungs to the tissues around the body. However, in people with sickle cell anemia, a sickle–shaped red blood cell develops as a result of the presence of an abnormal hemoglobin called hemoglobin S. Normally red blood cells contain hemoglobin A. But with hemoglobin S, there is a reduction in the amount of oxygen transported in the red blood cells.
As a result of this reduced oxygen, the cells change shape. These sickle-shaped cells are harmful because they often get stuck in small blood vessels, obstructing the flow of blood. This can lead to a number of complications, including recurrent episodes of pain known as asvaso-occlusive sickle cell crises.
These structurally abnormal cells also become very fragile and begin to be broken down prematurely, at a rate faster than the body can replace them. As a result, patients with sickle cell anemia often have a lower-than-normal number of red blood cells in their blood, condition called anemia. This can lead to a number of symptoms including fatigue, jaundice (yellowing of skin and eyes) and shortness of breath.
Sickle cell anemia can affect only someone who has inherited hemoglobin S from both parents. A person who inherits hemoglobin S from only one parent can have sickle cell trait (AS). Known as carriers, these people with sickle cell trait usually have no symptoms. They can, however, pass the trait onto their children.
To determine if a person has sickle cell anemia or sickle cell trait, physicians may order a number of blood tests (e.g., hemoglobin electrophoresis, sickle cell test). Newborns are routinely screened for the abnormal gene in many states. Adults, older children and fetuses can also be screened.
According to the Sickle Cell Disease Association of America, there are approximately 70,000 people living with the sickle cell anemia in the United States. Most of these patients are African American and Hispanic.
Currently, bone marrow transplant is the only cure for sickle cell anemia. The procedure, however, is risky, and it is often difficult to find a suitable donor. When a bone marrow transplant is not an option, the focus of treatment is on relieving pain and preventing crises and other complications