In 2020 two scientists (Emmanuelle Charpentier and Jennifer Doudna) received the Nobel Prize in chemistry for developing a technology for editing genes. Basically, that means cutting DNA wherever you want (gene editing).
Being able to precisely cut genes means that you can shut unwanted gene action down or add missing components to correct an abnormal gene. This opens the possibility of treating genetic illnesses by “fixing” the abnormal gene.
This technology is named CRISPR genome editing. Information about advances in the use of CRISPR technology is in the news, so this blog is intended to give you a basic grasp of what it’s about.
Although use of CRISPR gene editing is still in early phases of research for treating genetic diseases, there have been some exciting trials. For example, 11 patients with sickle cell disease have been treated by collecting certain bone marrow cells and editing the gene responsible for sickle cell disease.
These modified cells are re-introduced into the body. Over a period of 1 to 3 years, the patients have had a significant reduction in sickle cell crises in which red blood cells change shape and clog small blood vessels. This causes severe pain and damages tissue fed by these blood vessels.
The reduction in sickle cell crises has not been accompanied by any significant adverse side-effects. So far, this treatment appears to be both safe and effective.
Additional clinical trials have used CRISPR technology to treat other genetic disorders such as a rare disease of the retina of the eyes, reducing an abnormal protein (amyloid) in the liver, and hereditary angioedema (rare genetic disease with rapid swelling of tissue in multiple areas of the body such as hands, face, GI tract, and the airway).
In the future, it is expected that CRISPR will be used to reduce production of a protein that causes increased cholesterol and resultant heart disease and stroke. Already, clinical trials have started on treating cancer using modified T-cells in the body that attack and kill cancer cells. Engineered pancreas cells are being tested to treat type 1 diabetes.
CRISPR is an amazing technology that is going to change medicine as we know it. From a medical perspective, this is an exciting time to be alive.
Much of this blog is based on an article by Kan and Doudna in JAMA 2022; 328(10).
Peter M. Hartmann, MD
Family Medicine & Psychiatry
