Thalassemia, a form of anemia resulting in the abnormal formation of hemoglobin, is a genetically inherited disease that affects many. The two types, alpha thalassemia and beta thalassemia tend to have different prevalence rates in separate areas of the world. Alpha thalassemia is common in people of southeast Asian descent and there are a high number of carriers in Sub-Saharan Africa and Western Pacific regions. On the other hand, beta thalassemia affects mostly people from a Mediterranean background.
This autumn, scientists at Yale University have successfully cured thalassemia in living mice using a simple IV (intravenous injection) treatment.  The new technique of gene editing can be delivered to living animals without producing harm as well as significantly decreasing unwanted, off-target gene mutations which notably differs to the much more prevalent CRISPR gene editing technique. The CRISPR technique is dependent on DNA-cutting enzymes to slice open DNA at a target site to edit a specific gene but not without a couple of downsides. Due to the large size of the enzymes, this treatment has been used in vitro rather than in vivo that was performed by the new gene editing system. Another issue with the previous technique is the large possibility of DNA cutting at parts, which were not originally the target genes.
Professor of Therapeutic Radiology and Genetics, Peter Glazer, together with his colleagues, has concluded that there is a protein in the bone marrow that has the ability to activate stem cells, which are needed for the gene editing. Artificially synthesized polymers, which are known as peptide nucleic acids or PNAs, were mixed with the protein to mimic DNA and bind to the target gene and form a triple helix. This process allows for the cell’s own repair mechanism to be triggered and aid in fixing the mutation causing the disease. Nanoparticles were used to transport the PNAs to the target mutation in the mice and, afterwards, the gene editing mixture was administered intravenously.
Four and a half months after the injection, the levels of hemoglobin were tested. The mice did not show to have any more symptoms of thalassemia and their hemoglobin levels were within normal range. This research is a great starting point in using gene editing techniques in treating various genetically inherited blood disorders. This means it would not only be limited to the treatment of thalassemia but also sickle cell anemia and hemoglobinopathy.
Edited by: Nelli Morgulchik and Daryn Dever