Should CRISPR be used to edit human genes to treat genetic diseases?
Experts weigh in on gene-editing technology.
In the case of a monogenic disorder like Duchenne muscular dystrophy, the potential benefits outweigh the risks. CRISPR gene editing can potentially eliminate the underlying cause of monogenic disorders—the errors in DNA—rather than just treating the symptoms and consequences. But we still have much to learn about the long-term risks of gene editing, so I believe it should be restricted to treating the affected tissues of patients with debilitating disorders, not changing the germ line [sperm or egg cells, which can pass genetic changes on to future generations].
Eric Olson, PhD, is chair of the Department of Molecular Biology and Genetics and director of the Hamon Center for Regenerative Science and Medicine at UT Southwestern Medical Center.
Gene editing to treat a disease is potentially an important pathway to alleviating suffering, and this research should be continued despite egregious misuse of the technology [a Chinese scientist’s recent claims of editing genes of human embryos]. Understanding the safety and efficacy of proposed human somatic cell genome-editing applications in the context of risks and benefits is paramount. Transparent and inclusive public policy debates should come before any use of gene editing beyond treatment or disease prevention.
CRISPR genome editing to treat diseases for which there are no cures or effective therapy is vital, and the initial results for some rare diseases, including blood and eye disorders, are exceptionally promising. This strategy may [also] be useful in cancer to rev up the immune system by editing the patient’s T cells. The benefit-to-risk balance for somatic genetic disorders is very favorable, unlike the unknowns of editing and implanting human embryos.
Real progress is being made using CRISPR and related gene-editing techniques to alter cells taken from people with diseases such as sickle cell and genetic forms of blindness. These approaches are likely to offer safer and more reliable ways of making changes to a person at the genetic level. What makes these uses much less ethically challenging [than germline editing] is that they only affect the person being treated; the genetic modifications can’t be passed on to future generations.
It may well be unethical for us not to use CRISPR to treat genetic diseases, but the devil is in the details. Safety concerns are obviously a major issue, and much work needs to be done on a disease-by-disease basis before it becomes a reality.