Gene Editing and the Treatment of Hemophilia B
The discovery of the CRISPR/Cas9 system forever changed our world, allowing scientists to quickly and efficiently edit DNA. Of course, we could edit DNA before; however, the methods were not terribly precise. And what is, perhaps, most notable about the CRISPR system is that it allows scientists to make their edits at a reasonable price. And in a world where scientific breakthroughs are largely determined by whether or not one is able to get funding for their research, the significance of affordable techniques simply cannot be overstated.
So how does it work? In short, Cas9 is one of the enzymes produced by the CRISPR system. It binds to DNA in a highly sequence-specific manner and cuts it, allowing for accurate DNA manipulation.
With this technique, gene editing has truly taken off. It is highly more efficient than the previous mainstream methods that make use of TAL Effector Nucleases (TALENS) and Zinc Finger Nucleases (ZFNs), and the new method paves way for more researches and, possibly, using the use of gene editing to treat human illnesses and ailments.
In fact, this is precisely what researchers from Richmond, California's Sangamo BioSciences are trying to do.
It was announced that the company has received USC FDA clearance to conduct studies on treating hemophilia B using gene editing methods. This is a genetic disorder wherein the liver fails to produce Factor IX, a key protein responsible for clotting blood, putting sufferers at constant risk of uncontrollable bleeding,
This will be the first in vivo genome editing application to enter the clinic. And of course, the method makes use of the CRISPR/Cas9 system.
Recently, the National Academy of Sciences, National Academy of Medicine, Chinese Academy of Sciences, and the Royal Society of the UK held an international summit on human gene editing. One of its conclusions was that genetically edited human cells or embryos must not be used to establish a pregnancy.
Despite the possibility that the method may become a treatment for hemophilia B, many, including scientists, are still skeptical about the approach. Individuals are worried that the DNA-splicing method could cause unforeseen and potentially devastating side effects. As a result, no implementations should be incorporated into humans, the scientists argue, until we are absolutely sure of the impact on the human genome and human body.
The method outlined in the study involves moving the Factor IX gene closer to a promoter for albumin. Since the liver produces albumin naturally, putting the Factor IX genes right next to albumin's promoter should get the liver to produce both. The team has already tested the treatment on both rodent and simian models, with great success.