STEVE INSKEEP, HOST:
NPR's learned that a scientist in Sweden is trying something sure to be controversial. He is the first scientist in the world known to be trying to genetically modify healthy human embryos, which raises many questions about how far this science is going to go. NPR health correspondent Rob Stein is breaking this story.
ROB STEIN, BYLINE: Hi, Steve. Nice to be here.
INSKEEP: I'm glad you are here. Who is this scientist and what exactly is he trying to do?
STEIN: So his name is Fredrik Lanner. And he's a developmental biologist at the Karolinska Institutet in Stockholm. And he's using a brand new kind of genetic engineering that allows scientists to make changes in the DNA in human embryos in ways that were never possible before.
INSKEEP: Why does he want to do that?
STEIN: So he wants to do it for basic medical research. He has two goals, really. One is to find new ways to treat infertility and prevent miscarriages by understanding the genes that control early human embryonic development. The second one is to learn more about human embryonic stem cells, which scientists want to use the treat all kinds of incurable diseases like Alzheimer's and Parkinson's and blindness and diabetes. By understanding the genetics of early embryos, he hopes to help them do that.
INSKEEP: OK. That all sounds great. Why are people so worried about something like this happening?
STEIN: Well, the fear is that somebody might take this further and try to create genetically modified human beings using genetically modified human embryos. And the concern there is that they could make some kind of mistake. I mean, this is new science. They don't really know how well it works. They could accidentally create a new disease that would then be passed down for generations and kind of mess up the human gene pool for generations.
INSKEEP: This isn't the same way that people do genetically modified plants. We're talking about genetically modified people.
STEIN: Well, that's the fear - is that they could use these techniques to create, someday, genetically modified people. You know, designer babies, where parents pick and choose the traits of their babies - make them taller or stronger or smarter, something like that - we're nowhere near being able to do that. But the concern is that this could open the door to, someday, somebody trying that.
INSKEEP: So NPR's Rob Stein is reporting, again, that a scientist is working with human embryos to modify them for the first time for medical research.
He let you into his lab, first reporter to be in there. What was it like?
STEIN: Yeah, so I traveled to Stockholm, and I went to his lab. And his labs are right upstairs from an IVF clinic. And that's what he's using are leftover embryos from couples who went through IVF to try to have babies. These are very early embryos - only 2 days old, only four cells. And it was fascinating to watch. Everything they were doing was projected onto a monitor and magnified. And you could see these tiny embryos in the dish under the microscope and this tiny little needle piercing the shell of the embryo so they can inject this genetic engineering tool I mentioned. Lanner refers to it as kind of a genetic molecular scissor that cuts the DNA in very precise places.
STEIN: Let's listen a little bit as Lanner looks over the shoulder of his assistant as he tries to edit one of these embryos.
FREDRIK LANNER: So now he just injected the second embryo. And you can see the little area there where the solution has been injected. And that's where we would have the scissors.
STEIN: That's how you edit the DNA in a human embryo - that's what you just did. That's how you go about doing it?
LANNER: Yeah, yeah.
INSKEEP: I'm just trying to think of tiny scissors small enough to fit inside one human cell. This is amazing.
INSKEEP: But what did he say when you raised the ethical concerns that we're talking about here?
STEIN: Lanner said, well, look it - listen, I have no intention of doing any those sci-fi kinds of things that people are worried about. All I want to do is basic research to help women have babies. Let's listen a little bit what Lanner said when I talked to him about these concerns.
LANNER: I think this is something with all new technology - that it has good use and it could have sort of use that is not morally acceptable - right? - and designing babies or making sure you have a blue-eyed baby or something similar. The only way we can sort of prevent that from happening is to have a - good laws regulating this.
STEIN: And in fact, Lanner told me that right now, at least, in Sweden, it would be illegal to try to make a human being from a genetically modified embryo. But that's not the case in all parts of the world. There are countries where it would be legal. And there are other scientists in other parts of the world who are starting to do experiments using genetic modification on human embryos.
INSKEEP: The same way that this man is?
STEIN: Yeah, they do similar kind of basic research right now.
INSKEEP: Rob, thanks very much for bringing us this story.
STEIN: Sure. Great to be here.
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