DAVID GREENE, HOST:
A Chinese researcher has shocked the world by claiming to have created the first genetically modified humans. Last night, he faced harsh public scrutiny from his fellow scientists. He Jiankui appeared before hundreds of his peers at an international summit in Hong Kong. The scientists there were skeptical. In many cases, even outraged. NPR health correspondent Rob Stein joins us now. Hey there, Rob.
ROB STEIN, BYLINE: Hey, David.
GREENE: All right. So as you've been reporting, this scientist claims that he edited the genes of twin girls to resist the HIV virus. What was the reaction like in Hong Kong to this?
STEIN: Yeah. It was a pretty dramatic moment at the summit. At the very beginning, David Baltimore, he's this Nobel Prize-winning biologist who's running this meeting, he took the liberty to kind of interrupt and tell He point blank that he thinks what he did was irresponsible and really completely unjustifiable. Let's listen a little bit to what he said.
(SOUNDBITE OF ARCHIVED RECORDING)
DAVID BALTIMORE: I don't think it has been a transparent process. We've only found out about it after it's happened and after the children are born. I personally don't think it was medically necessary.
STEIN: So you can hear, David, I mean how incensed he was. And that was pretty much the tone overnight at this meeting in Hong Kong.
GREENE: Well, tell us more about this meeting where this was all taking place.
STEIN: Yeah. So this was an international summit that was organized for this very reason, to try to reach a global consensus on whether, when and how it might be ethical someday to use these powerful new gene editing techniques to create genetically modified people. But no one had any idea that he was going to make this claim at the very start of the meeting. So everybody was pretty stunned. And one scientist after another, and a bioethicist after another stood up and really grilled He about, you know, why did you choose HIV to do this, and were the parents who volunteered to do this informed about it? Did they really understand what they were getting into? And how does he know that this is safe and these kids aren't going to suffer some terrible complications down the road?
GREENE: Wow. So while facing a very skeptical, even angry crowd of peers, how did he present his work?
STEIN: You know, he's a pretty low-key kind of guy and he, you know, very carefully walked through the details of his research, which used this powerful new gene editing technique called CRISPR. He says he first studied mice and monkeys, and then he decided to try to genetically modify human embryos from seven couples in his lab in China. And finally, he produced these two twin girls a few weeks ago. He said their names are Lulu and Nana, and they're home with their parents. And he says, you know, they appear healthy and one of the girls, he says, now appears to be immune from the AIDS virus. And he said he did this in hopes of protecting these girls and lots of other kids from AIDS down the road.
Now, you know, if true, these girls would be the world's first genetically edited human beings, and that would be a landmark in human biology that many scientists are comparing to the birth of, you know, the first test-tube baby, Louise Brown. And arguably, this could be even more groundbreaking because it alters the human genetic blueprint for generations. And, you know, He also revealed that he has another pregnancy early on that's already underway.
GREENE: Wow. So he's doing more of this work. Do we - I mean, when you first reported this, there were some questions about whether he actually did what he said he did. Are there still questions?
STEIN: Yeah. There are still really big questions. I mean, you know, he completely ignored all the usual rules of science by making his claims in a series of YouTube videos instead of letting scientists scrutinize his data first. And, you know, so everybody's still waiting to really examine the details to know whether he did what he said he did. And he also could be in big legal trouble when he gets back to China.
GREENE: NPR health correspondent Rob Stein. We appreciate, Rob. Thanks.
STEIN: Sure. Nice to be here, David.