What is Sickle Cell Anemia?

So this week I signed up to be a volunteer at Camp Boggy Creek in Florida for a week over the summer (thanks Genetic Counseling Discord for the opportunity. Basically, this camp provides the opportunity for people with various medical conditions to enjoy a week at camp. They organize their summer in weeks according to different conditions and the week that I signed up for is their Sickle Cell Anemia week, so I figured I would learn some more about the condition.

First, let’s start with the genetic cause of Sickle Cell Anemia. When someone has Sickle Cell, it means that their HBB gene has a mutation in it. The HBB gene codes for 2 subunits of hemoglobin called beta-globin. The mutation would change the normal beta-globin to an abnormal form of it, like hemoglobin S. In people with Sickle Cell Anemia, both of the subunits are changed to hemoglobin S, while in Sickle Cell disease, only 1 of the subunits is altered. When these changes happen, it causes the red blood cell to be a sickle shape.

This massive difference in the cell structure comes from one, single amino acid change, Glu6Val, meaning that at the 6th amino acid, a glutamic acid is changed to a valine. Isn’t in incredibly that one change can cause such a drastic difference in the shape of the cell?

This condition follows what is known as a recessive inheritance pattern. This means that the person has to inherit one mutated copy from each of their parents in order to present with sickle cell anemia.

There is quite a bit of a range in the presentation of symptoms when it comes to Sickle Cell Anemia. Some people don’t have a whole lot of symptoms, while others are hospitalized frequently. The sickle shape of the red blood cells can cause someone to become anemic, which presents as shortness of breath, fatigue, and delayed growth and development. Additionally, painful episodes can occur if a clump of cells get stuck in a small blood vessel, which can then lead to potential organ damage.

Sickle Cell Anemia is most common in people with African decent. The National Institute of Health estimates that 1 in 5oo African Americans in the US have sickle cell.

One incredibly interesting thing about sickle cell (in my opinion) is that studies have shown that sickle cell has been advantageous against malaria. It has been shown that people who have one copy of the mutated HBB gene (heterozygotes) and live in areas with high numbers of malaria, are less likely to die from malaria than people with two normal copies of the gene. However, researchers aren’t seeing the same thing when they look at people who have two mutated copies of the HBB gene (and have all of their red blood cells sickled). Thinking about this makes me want to study it more and makes me even more interested in epidemiology and public health.

Information from the National Institute of Health (Genetics Home Reference) and NCBI

I am so excited to volunteer with others who have this condition and to learn more about it while having fun at camp! I had a lot of fun doing some quick research today (read: procrastinating school work) and I just can’t wait to go to camp in late July!

Yours in blog,

Makena