Sickle Cell Genetic Treatment
Sickle cell anemia is a very prominent disorder that affects over 20 million people worldwide (1). This condition is a blood disorder that is caused by mutations in the hemoglobin of red blood cells (2). When mutated, the red blood cells will undertake a crescent shape (which is what gives it the “sickle” name) which restricts their flow throughout the body and prevents oxygen transport. If enough cells sickle, the patient could develop life threatening disability or death (2). Due to the extreme prevalence of sickle cell anemia, a treatment that cures its effects could have massive impacts worldwide. For the first time, 2 cell based gene therapies have been approved for use in people ages 12 or older (2). One of the treatments, Casgevy, utilizes CRISPR/CAS9 (which can cut, replace, and repair DNA) technology to edit stem cells in the blood. The edited cell begins to produce a fetal form of hemoglobin called HbF, which increases oxygen delivery and prevents cell sickling2. The second therapy, Lyfgenia, has a different delivery mechanism. By utilizing vectors (which acts as a delivery mechanism for genetically modified material), scientists are able to modify patients' stem cells to produce a modified version of hemoglobin A (which isn't affected by sickle cell anaemia) (2). The modified stem cells have a reduced chance to sickle and block blood flow making this another invaluable treatment method. Casgevy has relatively minor symptoms like headaches and nausea with a 93.5% success rate. Lyfgenia patients have experienced blood cancer and low blood cell counts however, it still observed a 88% success rate and FDA approval (2). These two treatments are groundbreaking new discoveries that help pave the way for effective genetic treatment of many disorders previously thought untreatable.
What Is Sickle Cell Disease? (2023, April 22). NHLBI, NIH. https://www.nhlbi.nih.gov/health/sickle-cell-disease#:~:text=The%20condition%20affects%20more%20than,born%20with%20sickle%20cell%20trait.
U.S Food and Drug Administration. (2023). FDA Approves First Gene Therapies to Treat Patients with Sickle Cell Disease. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapies-treat-patients-sickle-cell-disease