The first genetically modified babies would be born in China

This milestone is not surprising. In 2015, Junjiu Huang of Sun Yat-sen University used CRISPR edit human embryos, but only non-viable embryos that would never have been able to give birth to a live birth. A second Chinese team will follow the next year. And last year, Shoukhrat Mitalipov of the Oregon University of Health and Science was the first to use this technique on viable embryos, without implanting one in a woman.

With such work, it seemed almost inevitable that someone take the steps that he did. "At one level, it's not a surprise at all," says Ellen Clayton, professor of law and health policy at Vanderbilt University. "On another, that's …", how literally she lost herself for the words and gave a big sigh. "It calls into question the possibility of control and I think it will exacerbate the public's fear," she added.

Socially, the creation of CRISPRPublished babies is a binary moment – a Rubicon that has been crossed. But scientifically, the devil is in the details, and most of them are still unknown.

CRISPR is still ineffective. Chinese teams that first used it to edit human embryos only succeeded in a small proportion of cases. Even then, they found disturbing levels of "untargeted mutations" in which they had erroneously cut parts of the genome off their target. gene. In his video, he claimed that his team had carefully sequenced the genomes of Nana and Lulu and found no change in genes other than CCR5.

This statement is impossible to verify in the absence of a peer-reviewed document or even published data of any kind. "The paper is where we see if the CCR5 gene was properly edited, what effect it had at the cellular level, and if [there were] out-of-target effects, " m said Eric Topol from the Scripps Research Institute. "It's not just" it worked "as a binary statement."

Read a CRISPR pioneer in gene editing: "We should not ruin everything"

Others were uncomfortable with the claims of He's video on YouTube. "It would be if you and I, the doctors, were developing a cold fusion reactor … without ever having designed the nuclear reactor, flipped the switch without any safety inspection or even checking if it was producing energy, then posted a video on Instagram, " Sandip Patel says, immunologist at the University of California at San Diego on Twitter.

In the video, he said that the use of CRISPR for human improvement, such as improving IQ or selecting eye color, "should be prohibited". About Nana and Lulu's parents, he said: "[they] do not want a designer baby, but simply a child who will not suffer from a disease that drugs can now prevent. "

But his reason is debatable. Huang, the first Chinese researcher to use CRISPR on human embryos, targeted the defective gene behind an inherited disease called beta-thalassemia. Similarly, Mitalipov has attempted to publish a gene called MYBPC3, the defective versions of which are causing another inherited disorder called hypertrophic cardiomyopathy (HCM). These uses are still controversial, but they are among the most acceptable applications for the editing of embryonic genes, as a means of treating inherited diseases for which treatments are difficult or non-existent.