What Kind of Mutation Is Sickle Cell Anemia?

Identification

Sickle cell anemia is a blood mutation that affects as many as 70,000 people in the United States. African-American and Hispanic-American populations are the most at risk for contracting this disease. It's an inherited condition that's transmitted through the genes of both parents. A condition closely associated with sickle cell anemia is sickle cell trait. Individuals with sickle cell trait are carriers of the gene but don't have the actual disease. However, a child born to parents who both carry the trait has a 25-percent chance of contracting the disease.

Causes

Sickle cell anemia is caused by sickle-shaped red blood cells, as opposed to the normal, disc-shaped blood cells of people who don't have this condition. Sickle cells are shaped in the form of a "C." Because of this shape, cells are unable to maneuver through arteries and blood vessels, and so have a tendency to clog the bloodstream. Another characteristic of this condition is a lower-than-normal number of red blood cells in the body, as is the case with all forms of anemia.

Hemoglobin Structure

The cause of the sickle-shaped mutation in the cells has to do with the hemoglobin contained inside them. Hemoglobin is an iron-rich protein responsible for carrying oxygen throughout the body. Hemoglobin also gives blood cells their red color. In the case of sickle cell anemia, abnormal-shaped hemoglobin account for the "C" shape of the cells. As a result, cells take on a stiff, cohesive-like texture that impedes their ability to flow and causes them to stick together.

Cell Lifespan

The anemic aspect of this condition happens as a result of the short lifespan that these cells have. Normal blood cells last up to 120 days in the bloodstream and then die off. Sickle cells only live from 10 to 20 days, and then die off. Red blood cells are manufactured by the body's bone marrow. As bone marrow can only manufacture so many cells at a time, there is an ongoing shortage of red blood cells available due to the short lifespan of sickle-shaped cells.

Sicke Cell Crisis

The blood cell mutations found in sickle cell anemia result in blockages that can occur in different areas of the body. In some cases, these blockages can cause sudden pain in the joints, lungs or abdomen. An attack of sudden pain is called a "sickle cell crisis" and occurs when blood cells form clumps in the bloodstream. As blood flows to the limbs and organs of the body, these clumps can get lodged inside small blood vessels. When this happens, pain is the result.

Symptoms

Common symptoms associated with this condition are headaches, fatigue, chest pain, and coldness in the hands and feet. Symptoms can vary from mild to severe, and in some cases may require hospitalization. Fatigue is the most common symptom apparent in sickle cell anemia. Part of this is due to the lack of oxygen being transported to the cells of the body. The shortage of blood cells, coupled with their abnormal shape, slows blood circulation and quickly depletes the oxygen supplies that are available.

References

• What Is Sickle Cell Anemia?

Resources

• American Sickle Cell Anemia Association