Sickle cell anemia is a condition in which a gene mutation affects the production of a component of red blood cells called hemoglobin. Hemoglobin aids the body in carrying oxygen throughout the body. It is also responsible for carrying carbon dioxide to the lungs for expulsion. The defect in hemoglobin causes the red blood cells to change shape from a round doughnut-like shape to a C-shape, according to the National Heart, Lung and Blood Institute. These sickle-celled blood cells can cause significant health problems, including organ damage and severe pain, stemming from blood vessel blockage.
Sickle Cell Trait vs. Sickle Cell Disease
Sickle cell trait is a condition in which a person has a mix of HbA (normal) and HbS (sickle cell) hemoglobin. It is notated as HbAS. According to the University of Maryland Medical Center, people with the sickle cell trait generally don't have symptoms of the condition; however, under certain circumstances, such as extreme stress or lack of oxygen, a person with HbAS may develop symptoms of the disease.
Sickle cell disease occurs when most, if not all, of a person's HbA hemoglobin are replaced with HbS hemoglobin. In this case, the person has sickle cell disease, which is notated as HbSS. People with HbSS will have the most severe symptoms and complications associated with sickle cell anemia. There three other notable types of sickle cell disease: Hemoglobin C, Hemoglobin E and Hemoglobin S-beta- thalassemia. Hemoglobin C is a condition in which a person has HbS hemoglobin as well as target cells called HbC. Symptoms of sickle cell anemia occur only if the HbS and HbC hemoglobin combine. Hemoglobin E is similar to Hemoglobin C; however, it occurs primarily in the Southeast Asian population. Hemoglobin S-beta-thalassemia occurs when a person has both the HbS mutation and the thalassemia genes.
Genetics
Sickle cell anemia is a genetic condition. The likelihood of a person being diagnosed with sickle cell anemia trait or sickle cell anemia disease depends on her parents' sickle cell status. According to the Mayo Clinic, both parents must be affected by the condition. If both parents have sickle cell anemia disease, there is a 100 percent chance that the child will have the disease; however, if both parents have the sickle cell trait, the chance of the child having the disease is reduced to 25 percent and the chance of the child having only the trait is 50 percent. If a parent has the trait or the disease and the other parent isn't affected by any form of sickle cell, there is a 50 percent chance that the child will have only the trait; however, the child won't have the disease.
Heritage
Sickle cell anemia is common among people of Indian, Spanish, Mediterranean, African and Middle Eastern descent. Asians are commonly affected with the Hemoglobin E disease. In the United States, approximately one out of every 500 African Americans have a form of sickle cell anemia and it will affect one out of every 1,000 to 1,400 Hispanics.
