Sickle cell disease is the most common blood disorder in the United States, affecting approximately 100,000 Americans. It is caused by a gene mutation that makes red blood cells collapse from a circle into a "C" or sickle shape. This deformation limits the ability of these cells to deliver oxygen throughout the body.
People with sickle cell disease, even young children, often experience fatigue, repeat infections, and periodic episodes of pain. While available treatments alleviate the symptoms, a cure remains elusive. But there is hope on the horizon.
Scientists, including Dana Carroll, Ph.D., from the University of Utah are now exploring an advanced DNA editing tool called CRISPR to repair the defective gene responsible for this disease. Scientists and doctors are excited about the possibility that one day CRISPR could radically change how certain diseases are treated.
But what is CRISPR and how does it work?
This futuristic technology may sound like something out of science fiction, but it has an even better back story. CRISPR, an acronym that stands for Clusters of Regularly Interspaced Short Palindromic Repeats, is a unique mechanism in bacteria that works like a primitive immune system. When viruses invade, CRISPR targets and cuts up their DNA.
Jennifer Doudna, Ph.D., professor of biochemistry and molecular biology at the University of California, Berkeley, saw the potential of this unique quirk of the bacterial immune system to develop new treatments and maybe even cures for human disease. A world-renowned pioneer of CRISPR gene editing technology, Doudna will present a lecture on this topic as part of the University of Utah Health Benning Lecture series.
In essence, researchers use CRISPR to scan a complete set of genes to find a bad gene and repair it. Think of it this way, CRISPR is like "find and replace" in a Word document. You open a copy of the book "Moby Dick" on your tablet. You can use the “find” function to search for the word "February" on the first page of chapter 8. You can quickly delete and “replace” with the word with "March." With this sophisticated editing technology in hand, researchers are now exploring whether CRISPR can fix genetic diseases.
CRISPR is not without controversy
Researchers often view this technology from two frames of reference. Some propose editing germ cells — eggs and sperm — for severe genetic disease. Others want to focus on editing body cells, basically any cell in the body other than sperm or egg cells.
With the first approach, editing the germ cells would not only prevent the disease in the person, CRISPR’s edits would also be passed on to future generations. This advance would be significant because it raises the possibility of being able to eradicate certain genetic diseases forever. However, the long-term health effects of this approach remain unclear.
The second approach is more realistic. Scientists are already finding ways to edit genes in body cells, similar to the study to treat sickle cell disease, which is currently being carried out in mice. A great deal of research remains to be done to translate this technique into actual treatments for people. But still, the future may be closer than we think.
Learn more: Doudna will present "Rewriting the Language of Life: The Biology, Technology and Ethics of DNA Editing" March 21 at 6:30 p.m. at the Huntsman Cancer Institute. She will explain how CRISPR is rapidly advancing biology and medicine and the difficult ethical issues posed by this ground-breaking technology. The talk is open to the public, but registration is required.