Two years ago, the news of the birth of twins in China whose embryonic DNA were modified by a scientist to prevent HIV infection, snowballed a worldwide discourse around the ethics of using DNA modifying technologies. Many governments rushed to legislate prohibitions on germline gene editing, which involve genetic changes that can be passed onto future generations, while still allowing for applications that can treat a specific disease within an individual. But it wasn’t until earlier this month that an international consortium released new guidelines on how to proceed.
The stakes were high, since Crispr, which can target and cut sections of DNA like a pair of molecular scissors, has myriad applications for medicines and other advancements. The International Commission on the Clinical Use of Human Germline Genome Editing report underlined the importance of assessing DNA editing technologies for their abilities to make specific targeted changes in DNA and ensure that there are no unintended changes in other parts of the genome during the editing process. The panel was convened by the U.S. National Academy of Medicine, the U.S. National Academy of Sciences, and the U.K.’s Royal Society which included members from 10 countries.
“[The commission] has a proceed with caution type of approach and there is a real effort to go slowly and judiciously in terms of what science can and can’t do right now,” said Sandra Soo-Jin Lee, associate professor and chief of the division of ethics at Columbia University. The recommendations, Lee added, are consistent with the discussions that have been happening over the last years. The report prudently identified the issues associated with unintended changes in genome and not knowing what kind of downstream cascading effects that could occur.
The commission also underscored the need for elaborate societal discourses on the issue before any country decides to allow germline gene editing for clinical use. “No country has yet decided that it would be appropriate to move forward clinically with heritable human genome editing, and clinical use of the technology is currently explicitly prohibited or not explicitly regulated in many countries,” the report noted.
National Institutes of Health Director Francis Collins called for a five-year moratorium on germline gene editing in Discover Magazine last year. “We must never allow our technology to eclipse our humanity,” Collins wrote. He also acknowledged that nonheritable gene editing holds great promise for many life-threatening diseases. “Indeed, such applications may offer the best hope not only for treating, but for curing, many of the nearly 6,000 human genetic diseases that still lack treatments,” Collins wrote.
The commission said DNA editing technologies could be used in the future to prevent inheritance of monogenic diseases—conditions caused by mutations in one gene—including muscular dystrophy, beta-thalassemia, cystic fibrosis, and Tay-Sachs disease. The Commission defines a serious monogenic disease as one that “causes severe morbidity or premature death,” the report said. But there should be careful assessment to ensure that there are no other unintended genetic changes caused in the process. The report cautioned against the use of DNA editing tools for polygenic diseases, in which multiple genes are involved and several environmental factors could trigger the condition.
But there are still some kinks to be worked out. Lee noted that the commission’s recommendation for countries using DNA editing tools to set up “competent regulatory bodies” to ensure adherence to guidelines may not be the best approach. “Science is not national. What scientists are doing is extremely networked and is very global,” said Lee. There needs to be more creative thinking in terms of what authority a government or an international body would have if scientists do not follow these recommendations, she added.
Leigh Turner, associate professor at the University of Minnesota Center for Bioethics, School of Public Health said that he envisions a scenario where clinics offering heritable genome editing may crop up in places where there is limited regulatory oversight similar to how clinics started offering unproven stem cell therapy. “What if there is cross border travel to avail these services. At a transnational level we may see a struggle to provide regulatory oversight,” he added.