What Are the Genetics of Sickle Cell Disease?

Sickle cell disease, also known as sickle cell anemia, is an inherited disease that affects a person's red blood cells. It produces an abnormal form of hemoglobin, the molecule that transmits oxygen in red blood cells. When the abnormal hemoglobin sticks together, it elongates red blood cells, which causes internal blockages.

Autosomal Recessive

• Sickle cell disease is autosomal recessive. In other words, in order to get the disease, a child must have two abnormal sickle cell genes, one from each parent.

Genome

• The defective sickle cell gene is found on chromosome number 11. It is the gene for hemoglobin-Beta, and the mutation in sickle cell disease produces hemoglobin-S instead.

Gene Therapy

• One potential treatment for sickle cell disease is to inject correct copies of the hemoglobin-Beta gene into a patient's bone marrow. The hope is that the body will use this gene to produce normal hemoglobin.

Significance

• As of 2009, 80,000 people in the United States have sickle cell disease. In addition, 8 percent of African Americans and 1 percent of Hispanic Americans are carriers of sickle cell disease, meaning they have one chromosome with the sickle cell mutation.

Fun Fact

• People who are carriers of sickle cell disease are genetically resistant to malaria.