CRISPR Cas9 based gene editing technology shows tremendous potential to treat blood disorders including Sickle Cell diseases (SCD).
What is Sickle Cell Anemia?
Sickle cell anemia is a blood-related genetic disease, which is caused by a mutation in a gene called HBB. HBB gene encodes a protein called Beta hemoglobin, which is a subunit of a larger protein called hemoglobin. This protein helps in carrying oxygen across the whole body.
In sickle cell anemia, a mutation occurs in which a single nucleotide from A is replaced with a T nucleotide. As a result, Valine amino acid is formed instead of glutamic acid.
The mutation occurs at the sixth amino acid in the HBB gene, resulting in the red blood cells become sickle-shaped. Moreover, they are unable to transport oxygen correctly. Which leads to several severe complications like delayed growth, sexual maturity, chronic fatigue and more.
Current Available Treatments for Sickle Cell Disease
The best available option for the treatment of Sickle cell anemia is a bone marrow transplantation. However, this procedure is associated with very high risk, and it is reserved mostly for patients below sixteen years.
Some of the significant risks associated with bone marrow transplantation is finding a donor, extremely expensive and may chances of death. Moreover, the procedure does not work for everyone and is limited to a minimal number of patients.
Another strategy is to target secondary complications accompanied with Sickle cell anemia such as infections, fatigue, pain, etc. These are treated by the administration of antibiotics and other pain-relieving medications.
Moreover, other recommendations include a blood transfusion.
Meanwhile, all these procedures are for a short time, aiming to reduce the severity; none of these try to cure the disorder altogether.
CRISPR Cure Sickle Cell Disease!
As a single base change at a single gene cause Sickle cell disease, therefore, make CRISPR cas9 an excellent candidate for treating it. CRISPR could be used to edit and correct the mutation, hence restoring the correct function of Beta hemoglobin.
Explore more about CRISPR: What is CRISPR cas9?
Video: A team of physicians and laboratory scientists has taken a key step toward a cure for sickle cell disease, using CRISPR-Cas9 gene editing to fix the mutated gene responsible for the disease in stem cells from the blood of affected patients.
Also, Vertex Pharmaceuticals licensed a new CRISPR/Cas9 based therapy – CTX001 aims to treat sickle cell anemia. The method involves the harvesting of blood cells from a sickle cell anemia patient. By utilizing the CRISPR – Cas9 gene editing approach to correct beta-globin mutation and re-implanted into the patient body. They are hence restoring the normal function of Hemoglobin. Successfully, the procedure achieved in mice having sickle cell diseases.
Similarly, a team of researchers from RICE University followed a similar approach of CXT001 to treat Sickle cell disease. The procedure involved the harvesting of affected cells from the patient blood and using CRISPR/Cas9 technique to edited B-globin gene mutant locus. Later, the edited cells are re-implementing and resulting in normal hemoglobin.
Moreover, Dr. Daniel Dever of Stanford University also used CRISPR cas9 approach to treat sickle cell disease. By using CRISPR, they first introduce DNA break in the ß-globin gene, followed by correcting it with homologous recombination.
Editas medicines, a company leader in CRISPR-based gene editing technologies shows that the two versions of this approach that’s CRISPR-Cas9 and CRIS PR Cpf1 may be used as a possible treatment for various blood disorders including Sickle Cell Anemia.
Another study published in the journal of the American society of hematology, where the researchers using CRISPR approach to corrected a mutated sequence of the HBB gene. They did so by utilizing Homology-directed repair system. These cells used were Hematopoietic stem cells and progenitor cells (HSPCs). HSPCs are specialized cells that can further divide into other blood cells. So, this can provide one of the potential treatments for SCD in the near future.
Soon after successful clinical trials, CRISPR based therapies such as CTX001, targeting HSPCs and more will be available commercially for the treatment of sickle cell anemia.
Explore More: 11 Diseases CRISPR Technology Could Cure!