It’s official: Crispr babies are gone—yet

A small group of protesters in London last week dared in the rain outside the Francis Crick Institute, where the Third International Summit on Human Genome Editing was taking place. A rare gathering, from a group Stop Designer Babies, waved signs calling for “Never again eugenics” and “NO HGM” (no human genetic modification). The group is campaigning against what it sees as a shift away from the scientific community’s use of gene editing for biological enhancement – to tweak genomes to give, say, higher intelligence or blue eyes. If that happened, it would be a slippery slope to eugenics, the group argues.

Three days later, at the end of the summit, it appears that the group’s wishes have been partially satisfied – at least for now.

After several days of experts discussing the scientific, ethical and management issues related to human genome editing, the summit organizing committee spoke with final word. Hereditary human genome editing — editing embryos that are then implanted to establish a pregnancy that can pass on their edited DNA — “remains unacceptable at this time,” the committee concluded. “Public discussion and political debate are ongoing and important to decide whether this technology should be used.”

The use of the word “or” in the last sentence was carefully chosen and carries a lot of weight, says Françoise Bayliss, a bioethicist who served on the organizing committee. Importantly, the word is not “how” — “that, I think, is a clear signal to say that the debate is open,” she says.

This marks a change in attitude since the closing of the last summit in 2018, during which Chinese scientist He Jiankui dropped a bombshell: He revealed that he had previously used Crispr to edit human embryos, resulting in the birth of three Crispr-edited babies. — to the great horror of the summit participants and the rest of the world. In its final statement, the committee condemned He Jiankui’s premature actions, but at the same time signaled with a yellow light, not a red one about editing the germline genome – that is, proceed with caution. He recommended the establishment of a “translational pathway” that could bring the approach to clinical trials in a rigorous and responsible manner.

Over the past half-decade or so, research has confirmed that germline genome editing is still too risky—and that’s before you start dealing with the massive ethical issues and societal implications. And these fears only intensified at this year’s summit.

These include, for example, mosaicism, when genome editing causes individual cells to be edited differently. Shavkhrat Mitalipov, a biologist from the Oregon Health and Science University, spoke at the summit. findings from his lab, which showed that germline genome editing led to unintended—and potentially dangerous—changes in embryo genomes that standard DNA-reading tests used to screen embryos before implantation might not detect. Another scientist, Dugan Wells, a reproductive biologist at the University of Oxford, presented research that looked at how embryos repair breaks in their DNA after editing. His work showed that about two-fifths of the embryos were unable to repair their broken DNA. A child that grows from such an embryo may have health problems.

The message was loud and clear: scientists don’t yet know how to safely edit embryos.

For Cathy Hassan, associate director of the Center for Genetics and Society, a California-based nonprofit that advocates for a broad ban on heritable genome editing, those few lines in the committee’s final statement were the most important takeaways from the summit. “I think it’s an important step back from the brink.”

But figuring out whether heritable germline editing will ever be acceptable requires much more work. “The conversation about whether we should do this needs to be much broader than what we saw at the summit,” Hassan says. The world needs to reach a broad public consensus on this issue, says Bayliss. She worries that the job will not happen. So far, these summits have led to a debate about where the field will go, but it is not yet known if a fourth summit will ever take place. “I think we haven’t had the tough conversations we need to have yet,” Bayliss says.