Altering the fabric of human DNA passed from parents to their children has long been the stuff of science fiction. Now, with new techniques like the CRISPR-Cas9, scientists are on the verge of making that a reality.
Researchers have already used the gene editing technique to make hornless cattle and alter the way plants inherit traits. But altering heritable traits in the human genome carries significant moral and ethical dilemmas, scientists say. For some scientists, the risks are too great for anything but a complete ban on the technology. For others, they suggest a global system of regulations that allows exceptions.
Supporters emphasize the benefits of modifying unwanted genetic traits in human embryos. This technology could be used to help prevent hereditary diseases from being passed from parents to their children, they say. But the same technique could also be used to alter other inherited traits, perhaps cosmetic ones, and raises the issue of so-called "designer babies," ethicists warn.
"The difficult line is between preventative medicine and enhancement," explained George Church, professor of genetics at Harvard Medical School, at a Thursday press briefing at the annual meeting of the American Association for the Advancement of Science in Boston on Thursday. For example, he said, preventing a child from having a muscular problem could lead to that child having stronger muscles than normal. "Is that acceptable?"
These sorts of concerns led to a consensus among scientists at a gene editing summit at the National Academy of Sciences in December 2015 that this technique should not be used to produce a human embryo for pregnancy. Period. Full stop. Red light.
But a 261-page report written by an international group of 22 experts across fields such as science, medicine, law, and ethics suggests perhaps it should be a red flashing light, as Richard Hynes, a cell biologist at the Massachusetts Institute of Technology and one of the authors of the report, describes it in an interview with The Christian Science Monitor.
"There are thousands of genetic diseases," he says. Collectively, a substantial percentage of the population grapples with the issues related to passing along these diseases to their children. As such, gene editing could be a huge help for these people and deserves some consideration – once it has been proved safe, of course.
And if the United States bans such techniques, Dr. Hynes says, people will likely seek them elsewhere. "It's much better to do it under a well-regulated system," he says, which is why his group suggest that there should be a process to stop and assess the moral dilemmas presented, instead of a blanket ban on the technology.
As such, the field needs "an overarching set of principles" that might be applied around the world, said Hynes, who was also on the panel at the AAAS meeting. And that's just what the new report was aiming to provide.
More research must be done on heritable genome editing before it should be applied to humans, the report advises. And even then, the group says, it should only be used to treat or prevent severe diseases when no other options are available. Furthermore, there must be strict criteria and oversight, and public engagement and input must be considered in regulation.
One of the big challenges in regulating this research is that science is global and laws are by country, Gary Marchant, a law professor at Arizona State University who was also an author on the new report, said on the press briefing panel at the AAAS meeting. As such, the group recommends coordination among regulators and informal mechanisms, such as professional society guidelines, journal publication requirements, and criteria to receive funding for research.
This sort of soft regulating has already been seen, as two prominent science journals, Science and Nature, refused to publish the results of a Chinese team that successfully edited genes in human embryos in 2015.
Designer babies around the corner?
Since the dawn of genetic research, fears have persisted that such technology could lead to a dystopian society in which people with the means could pay to alter the traits of their offspring to give them an advantage in life, or governments might use the technique to create super-soldiers.
We're not there yet, Hynes said at the press briefing. "It's a fantasy at the moment," he said. "We have no idea how to make designer babies."
For example, Hynes tells the Monitor, scientists can't edit a human genome to produce more intelligent offspring yet, because "we don't understand what makes people smart."
But Josephine Johnston, director of research at The Hastings Center, an independent bioethics research institute who was also on the press briefing panel, said, "I'm not sure I agree that we don't have designer babies today." She pointed out that potential parents can use existing reproductive technologies to exert some level of choice over embryos already, alluding to the use of genetic tests in selecting which embryos to implant with in vitro fertilization.
"You can't start from scratch," Dr. Johnston said, but parents already have a measure of control.