Gene Therapy to Possibly Cure Sickle Cell Disease in Africa

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SEATTLE, Washington — Sickle cell disease is a genetic condition that affects the shape of red blood cells, leading to many health complications. While the disease is manageable, some developing countries struggle to maintain the illness. For example, sickle cell disease in Africa contributes to an abnormally high rate of mortality. However, with new scientific discoveries, gene therapy may be able to change that.

Sickle Cell Disease

Sickle cell disease (SCD) tampers with the body’s ability to transport oxygen through the blood due to the red blood cells sickling. The molecule hemoglobin S causes the red blood cells to stray from their circular shape and deform. The resulting crescent-shaped blood cells can clog vessels and cause a lack of blood to organs. Moreover, if organs don’t get enough blood carrying oxygen, they will fail.

In addition to a lack of oxygen moving through the blood, anemia can occur when sickle cell disease causes red blood cells to die too early. SCD has different categories, one of the most common being sickle cell anemia. Anemia is a condition in which the body has less red blood cells than necessary, producing shortness of breath and fatigue.

Sickle Cell Disease in Africa

Sickle cell disease is not always fatal, but it can be depending on the country. Africa has struggled for many years with the disease, particularly sickle cell anemia. In 2006, Africa reported more than 200,000 people having sickle cell anemia. Furthermore, this disease dominates the illnesses in Africa, affecting up to 2% of children in some regions.

In Nigeria, sickle cell anemia is an inherited disease, affecting newborns 150,000 times each year. Besides having more occurrences than other countries, the death rate is also higher for sickle cell disease cases in Africa. Only 10% to 50% of children with sickle cell disease in Africa will survive.

Poverty and Sickle Cell

One of the reasons for a higher mortality rate among African sickle cell disease cases is poverty. Some medications and transfusions can treat this disease. However, these medications are expensive, making them unavailable to people living in poverty. For instance, in Africa, it is unlikely that a person with SCD would live longer than 20 years when in high-income countries the survival rate of children is nearly equal to a child without the disease.

The costly resources keeping the disease under control leads to people often dying from an infection. One of the most common infections in Africa is malaria. An unexpected result of inheriting one of the abnormal sickle cell genes is that the carrier will be safer from malaria due to some form of protection the gene offers. However, having two of the genes will increase the likelihood of death immensely. Two genes will result in the diagnosis of sickle cell anemia and therefore makes the body more open to infections.

Gene Therapy

This seemingly endless war with sickle cell disease in Africa has a newfound solution: gene therapy. Gene therapy can operate in two different ways. A medic can insert a healthy gene inside of the patient or alter a faulty gene. The gene therapy would be working to fix the HBB gene. The HBB gene can have a mutation leading to an error in the instructions, making hemoglobin production faulty, which would lead to sickle cell anemia.

There are two known methods for correcting sickle cell anemia with gene therapy. In the first method, a professional would insert a healthy HBB gene into a removed hematopoietic stem cell. The hematopoietic stem cells should produce proper red blood cells in the bone marrow once inserted back into the patient. The second method would be to increase the production of fetal hemoglobin by altering the gene in the DNA to stop the misshaping of the cells.

There have already been some trials run, and the experiments include tests to make sure it is safe for a new HBB gene to replace a damaged gene. Scientists have also run tests in which stem cells take in a gene that works comparably to fetal hemoglobin, but instead, produces therapeutic hemoglobin with hopes that it will stop the sickling.

SCD can cause many health complications and has a stronghold in Africa. Malaria and poverty only increase the troubles that sickle cell disease causes. However, due to gene therapy trials, a cure for SCD is now in sight. Gene therapy can alter genes and replace old ones to stop the body from sickling the cells. Today, due to gene therapy there is finally hope for eradicating sickle cell disease in Africa.

—Hailee Shores
Photo: Flickr

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