Jennifer Doudna, Nobel Prize winner and co-inventor of the CRISPR gene editing technique, recently discussed CRISPR and the future of human evolution on the TED Radio Hour. She talked about how CRISPR has enormous potential for treating diseases but also raises difficult ethical questions.
Discovery of CRISPR
About 11 years ago, Doudna and her collaborator, Emmanuelle Charpentier, were working with CRISPR-Cas9, a naturally occurring enzyme that bacteria use to defend themselves against viruses. They discovered that Cas9 attacks a virus by cutting up the viral DNA and changing its genome. Doudna and Charpentier realized CRISPR could be a breakthrough technology for genome editing – a technology that could change the world.
The CRISPR system gives scientists a tool that is far more programmable and precise than previous gene editing technologies. It targets exact DNA sequences to cut and alter. CRISPR has put us on the brink of the next scientific revolution, a prospect that is both exciting and scary.
Current Applications of CRISPR Gene Editing
CRISPR has moved out of the lab into the wider world. Clinical trials are now being conducted testing the use of CRISPR gene editing to treat heart disease, sickle cell disease and other blood disorders, muscular dystrophy, and eye disorders.
This research is still in the early stages, but results have been promising. CRISPR-based therapies have the potential to treat diseases at their source. For example, in the sickle cell trials, CRISPR is used to edit the DNA in blood stem cells that have been removed and then put back into the patient’s body. The altered cells end up replacing the person’s original red blood cells.
The power of CRISPR technology to change evolution raises difficult issues that we have to address.
Using CRISPR-based therapies to treat deadly diseases certainly seems desirable, especially if the treatments are proven to be safe. It still raises questions of access. Who will be able to get these treatments? Who will pay? Who will make those decisions?
Beyond treating diseases, CRISPR editing has other applications that will likely be far more controversial. Should we engineer designer humans? We don’t have the technology to do this yet, but we will. Is it ethical to alter DNA to make people more resistant to disease? How about giving people higher IQs? To take it even further, is it okay to give parents the option to choose the traits they want for their children as if they were ordering from a menu?
Doudna believes we need to take more time to work out the ethical questions. About six years ago, she and her colleagues called for a worldwide pause on using CRISPR gene editing technology in human embryos.
However, in 2018, the world learned that a group of scientists had already gone ahead and used CRISPR to alter the genes in two embryos, which were implanted and born as twin girls with edited DNA. Doudna was horrified. It was highly unethical. The procedure had not been tested for safety, and the patients were not given enough information to provide informed consent. There was an international outcry from scientists, the United Nations, and the World Health Organization.
The future of gene editing
CRISPR technology will change the way we treat disease. If someone has a genetic susceptibility to a certain disease, such as Alzheimer’s, we may be able to alter their genes to prevent the disease before it even starts. Doudna thinks it’s very possible we may have the technology to do this within the next 30 years.
The benefits are clear. But we need to be mindful of the dangers. CRISPR will give us the unprecedented ability to control our evolution, and this is a power that we have to use wisely.