At the conference, who organizers included Jennifer Doudna, one of the inventors of Crispr technology, Dr. He gave a careful talk about something that fellow attendees considered squarely within the realm of ethically approved research, said one of those who attended, Dr. Fyodor Urnov, deputy director of the Altius Institute for Biomedical Sciences and a visiting researcher at the Innovative Genomics Institute at the University of California, Berkeley.
"If you listened to his talk, it is this very cautious, thoughtful, step-by-step advance," Dr. Urnov said. "He presented embryo editing of CCR. He was presenting the talk to peers, professional gene editors who knows that the field is advancing quickly, so frankly the atmosphere in the room was, I do not want to say hu-hum, but it was 'yeah, sure, you' ve built on ten years of advances. '"
"What we now know is that as he was talking, there was a woman in China carrying twins," Dr. Urnov said. "He had the opportunity to say 'Oh and by the way, I'm just going to come out and say it, people, there's a woman carrying twins.'"
He did not. "I would never play poker against Dr. He, "Dr. Urnov said.
Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology, who co-led an advisory group on human gene editing for the National Academy of Sciences and the National Academy of Medicine, said that group and a similar organization in Britain had determined that if human genes were to be edited, the procedure should only be done to address "serious unmet needs in medical treatment, it had to be well monitored, it had to be well followed up, full consent has to be in place."
It is not clear why altering genes to make people resistant to H.I.V. is "a serious unmet need." Men with H.I.V. do not infect embryos. Their semen contains the virus that causes AIDS, which can infect women, but the virus can be washed off their sperm before insemination. Or a doctor can inject a single sperm into an egg. In either case, the woman will not be infected and neither will the babies.
Dr. He got his Ph.D, from Rice University, in physics and his postdoctoral training, at Stanford, was with Stephen Quake, a professor of bioengineering and applied physics who works on sequencing DNA, not editing it.