The world's top geneticists met in Washington, DC Tuesday to discuss the future of human genome editing at a summit that is among the most important ever held on the topic. By Thursday, the group hopes to decide on a tentative path forward for potential human applications of powerful gene editing techniques such as CRISPR/Cas9, which can target and modify DNA with great specificity.
CRISPR has been hugely hyped for its potential to create safer, more precise genetically modified organisms—its promoters have suggested that we could de-extinct animals, modify mosquitoes to naturally eradicate malaria, and create drought- and heat-resistant crops for a world that's increasingly threatened by climate change, for example. But the potential applications for CRISPR don't stop there, of course. There's reason to believe that scientists could edit the human genome to end genetic disease, make us live longer, and create designer babies.
Experiments on nonviable human embryos started in China earlier this year, meaning we may be close to a future where any organism can be edited. Any talk of editing humans comes with enormous ethical questions about the morality and safety of modifying the human genome, which is why the summit was called.
The hope is that a consensus will form and international guidelines can be issued about the oversight of the technology. The plan is to issue a statement on Thursday that can be then used to inform regulatory decisions on a national and international level. Whether that'll actually happen is anyone's guess: Even if the group does come to a consensus, some at the conference say the discussion will need to be ongoing.
"This meeting should by no means be considered the final word on this very contentious and profoundly important issue, but it should be an early step in a public conversation," Marcy Darnovsky, director of the Center for Genetics and Society, told the audience.
Among the options on the table: A complete (but temporary) ban on any human genome editing that could be passed to the next generation.
"Individuals whose lives are potentially affected by germline manipulation could extend many generations into the future"
About halfway through Tuesday's proceedings, Hille Haker, an ethicist at Loyola University Chicago, called for a two-year moratorium on so-called "germline" gene editing, which would edit traits that can be passed to the next generation. Haker said germline editing violates the rights of women and of children who could be born with an edited genome. She was the first person at the conference to call for a total ban on the practice.
Haker's proposed two-year ban on germline gene editing would still allow what she called "social, ethical and legal research accompanying somatic gene editing [which edits nonsex cells in adults], and basic research for germ line gene editing during the time of the moratorium," which she would like to see extend the next two years. Somatic gene editing is therapy only affects the individual, unlike germline editing, which is passed on to the next generation.
"[Germline gene editing] violates medical and ethical norms because it disregards the patient….It exposes women and future children to to non-justifiable health risks," Haker said.
Haker was among the dozens of scientists and ethicists who warned about the danger of human genetic editing in a letter published by the Center for Genetics and Society last month. Though she is a Catholic ethicist, some of Haker's concerns are shared by important secular scientists around the world. Last week, Francis Collins, director of the National Institutes of Health, wrote that the "ethical arguments against human germline engineering are significant."
"A most compelling [argument] is that medical research should always seek to balance benefits and risks, with individuals who are participating in research giving fully informed consent," he wrote. "But the individuals whose lives are potentially affected by germline manipulation could extend many generations into the future. They can't give consent to having their genomes altered from what nature would have made possible."
"We will eventually address unintended consequences"
That said, CRISPR and other genome editing technologies are undeniably powerful tools—proponents say that gene editing could potentially end genetic disease, for example. For that reason, many of the speakers Tuesday noted that, though there are potential medical and ethical risks, research into human genome editing should continue.
"Having a moratorium doesn't make any sense. Responsible research should be happening in the background all the time," Kyle Orwig of the University of Pittsburgh said in response to Haker. His comments received a light applause from the room.
"A small group of human tinkerers did indeed optimize, for modern needs, IR8 rice, border collies, and many other forms of life," George Church, a Harvard University researcher who is one of CRISPR's biggest proponents, wrote last week. "We will eventually address unintended consequences, if any, not via prejudicial bans lacking end points, but by encouraging experiments—as was done with in vitro fertilization, medications from recombinant DNA, and genetically modified crops."
Another audience member called the suggestion of a ban a "serious overreach."
The fiery ethical discussion of the societal implications of using particular gene editing techniques were a wrench in a mostly peaceful day of quiet agreement that CRISPR holds huge promise to perhaps prevent genetic disease or engineer humans to live longer, healthier lives.
Darnovsky pointed out that the summit had no representatives from advocacy groups representing people with disabilities, people of color, women's health organizations, the LGBT community, or labor groups.
"Human germline gene editing, if it were to be implemented, would affect and alter not just future human beings, but also it would alter future human societies, profoundly so," Darnovsky said. "[Gene editing would be] a radical rupture with past human practices that could have irreversible and reverberating impact on society."