The science and ethics of genetic editing


A scientist modifying a piece of DNA. Photo courtesy of the Genetic Literacy Project via Creative Commons.

Jayden Butler, Author

The debate about genome editing is not a new one but has regained attention following the discovery that CRISPR has the potential to make such editing more accurate and even “easy” in comparison to older technologies. CRISPR is a bacterial immune system turned into a powerful gene-editing tool. For nearly five years, researchers have been wielding the molecular scissors known as CRISPR to make precise changes in animals’ DNA.

Most of the ethical discussions related to genome editing center around human germline editing. This is because changes made in the germline would be passed down to future generations. Some researchers and bioethicists are concerned that any genome editing, even for therapeutic uses, will start us on a slippery slope to using it for non-therapeutic and enhancement purposes, which many view as controversial. “This is a remarkable technology, with many great uses. But if you are going to do anything as fateful as rewriting the germ line, you’d better be able to tell me there is a strong reason to do it,” says Eric Lander, who is director of the Broad Institute of Harvard and MIT and who served as leader of the Human Genome Project. “And you’d better be able to say that society made a choice to do this—that unless there’s broad agreement, it is not going to happen.” Others argue that genome editing, once proved safe and effective, should be allowed to cure genetic disease. They believe that concerns about enhancement should be managed through policy and regulation.

Dietram Scheufele, a professor of science communication at the University of Wisconsin-Madison, and colleagues surveyed 1,600 members of the general public about their attitudes toward gene editing. The results revealed that 65 percent of respondents thought that germline editing was acceptable for therapeutic purposes. When it came to enhancement, only 26 percent said that it was acceptable and 51 percent said that it was unacceptable. Interestingly, attitudes were linked to religious beliefs and the person’s level of knowledge of gene editing.

“Among those reporting low religious guidance,” explains Prof. Scheufele, “a large majority (75 percent) express at least some support for treatment applications, and a substantial proportion (45 percent) do so for enhancement applications.” He adds, “By contrast, for those reporting a relatively high level of religious guidance in their daily lives, corresponding levels of support are markedly lower (50 percent express support for treatment; 28 percent express support for enhancement).” Among individuals with high levels of technical understanding of the process of gene editing, 76 percent showed at least some support of therapeutic gene editing, while 41 percent showed support for enhancement.

As with many new technologies, there is concern that genome editing will only be accessible to the wealthy and will increase existing disparities in access to health care and other interventions. Some worry that taken to its extreme, germline editing could create classes of individuals defined by the quality of their engineered genome. Ms. Hammel, a biology teacher at Battlefield High School, explains her viewpoint in an interview. She says, “While genetic editing clearly has many good-natured applications, I believe its potential cons far outweigh any good it could bring. The only reason I could seed a need for it would be for medical purposes, to prevent a divide in the wealthy using the enhancement aspect to their advantage.” Bioethicists and researchers generally believe that human genome editing for reproductive purposes should not be attempted at this time, but that studies that would make gene therapy safe and effective should continue. Most stakeholders agree that it is important to have continuing public deliberation and debate to allow the public to decide whether or not germline editing should be permissible. As of 2014, there were about 40 countries that discouraged or banned research on germline editing, including 15 nations in Western Europe, because of ethical and safety concerns. There is also an international effort led by the US, UK, and China to harmonize regulation of the application of genome editing technologies. This effort officially launched in December 2015 with the International Summit on Human Gene Editing in Washington, DC.