CRISPR Applications {Blood Disorders - Sickle Cell Anemia & β Thalassemia}

Sickle Cell Disease (SCD) is an inherited blood disorder. With SCD the normally disc shaped red blood cells (RBC) are mutated into a crescent shape, distorting the shape and function of the RBC. Because of this crescent shape, the deformed blood cells have trouble traveling through blood vessels often getting stuck, clotted, or completely blocked. All of these can result in slowed blood flow and oxygen to vital parts of the body. SCD often creates a shortage of oxygen for the body as blood flow is restricted and or blocked. Additionally while healthy disc shaped RBC have a lifetime of around 120 days, Sickle cells live for around only 10-20 days before completing the cycle of apoptosis.

     β-thalassemia is also an inherited blood disorder. People with  β-thalassemia are not able to make a sufficient amount of hemoglobin. Hemoglobin is affluent with iron rich proteins. Hemoglobin carries oxygen to parts of the body.  β-thalassemia effects this process, starving the body of oxygen as is the case in SCD. There are a few types of  β-thalassemia, for the purpose of this study and post we will be focusing on the most severe - Beta Thalassemia Major (Cooley's anemia). With this type of  β-thalassemia two genes are affected creating a more severe illness that along with SCD requires frequent blood transfusions.  

Both of these disorders require frequent blood transfusions and hospitalizations. The need for blood transfusions continues to grow at a rapid rate while the supply plummets. With blood transfusion, there are many factors one has to consider, first blood typing. It can be harder to find the right blood if you are not o+ a universal receiver. Additionally blood transfusions can cause a build up of iron, which can become life threatening.  Blood transfusions serve as a 'stabilizer' at best. 

Because both SCD and  β-thalassemia are inherited disorders, the genes have mutated.  As a result of these mutations CRISPR would seem to be a wonderful treatment, or even cure for these blood disorders. As early studies demonstrate. Companies like Vertex Pharmaceuticals, CRISPR Therapeutics and Bluebird Bio are all in various stages of clinical trials. My next post will discuss the specifics of the procedure.

Please don't hesitate to comment any questions.

Work Cited

 Kaiser, Jocelyn, and Lucy Hicks. “CRISPR and Another Genetic Strategy Fix Cell Defects in Two Common Blood Disorders.” Science, 8 Dec. 2020, www.sciencemag.org/news/2020/12/crispr-and-another-genetic-strategy-fix-cell-defects-two-common-blood-disorders.

Stein, Rob. “A Year In, 1st Patient To Get Gene Editing For Sickle Cell Disease Is Thriving.” NPR, NPR, 23 June 2020, www.npr.org/sections/health-shots/2020/06/23/877543610/a-year-in-1st-patient-to-get-gene-editing-for-sickle-cell-disease-is-thriving.

Pagliarulo, Ned. “New CRISPR, Gene Therapy Results Strengthen Potential for Treatment of Blood Diseases.” BioPharma Dive, 12 June 2020, www.biopharmadive.com/news/crispr-vertex-bluebird-sickle-cell-thalassemia-study-update/579692/.