The Call-In: Genetic Engineering Last week, a new study was released confirming that scientists had successfully modified human embryos to eliminate a genetic defect. We asked you for your questions.
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The Call-In: Genetic Engineering

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The Call-In: Genetic Engineering

The Call-In: Genetic Engineering

The Call-In: Genetic Engineering

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Last week, a new study was released confirming that scientists had successfully modified human embryos to eliminate a genetic defect. We asked you for your questions.


And this is The Call-In.


GARCIA-NAVARRO: Today we're talking about genetic engineering. Last week, an international team of scientists reported that they had successfully edited the DNA of human embryos to repair a serious mutation. The scientific advancement raises a lot of questions, and we asked you for yours.

KATHY WILLIAMS: Hi. This is Kathy Williams (ph) from Waldport, Ore.

DENNIS COX: My name is Dennis Cox (ph).

PENNY BRADFORD: My name is Penny Bradford (ph).

WILLIAMS: I've got several questions on genetic engineering.

BRADFORD: My biggest question would be, where do you stop?

COX: I don't see that this technology will ever be stopped because somewhere in the world, it will, quote, unquote, "progress."

CAROLYN STRONG: I think this is a wonderful opportunity.

SEAN RYAN: Thank you.

MARYLUE BODENMILLER: Thank you very much.


RYAN: Bye.

GARCIA-NAVARRO: I'm joined now by Rob Stein. He's a correspondent and senior editor on NPR's science desk. And he's here to help answer your questions. Rob, thanks for being here.

ROB STEIN, BYLINE: Oh, sure. Nice to be here.

GARCIA-NAVARRO: This past week, we learned scientists have figured out how to edit the genes of human embryos. Explain to us what they did. And we should note that they actually destroyed what they created after they did it.

STEIN: That's right. I think it's important to make clear right off the bat that nobody made a baby here. Nobody made a genetically modified human being or anything close to that. So what they did is they went in with this powerful new genetic editing tool known as CRISPR; it's got that funny name. And essentially what it does is it lets scientists go in and edit the DNA in anything, including human embryos, very easily and very precisely. So it's sort of like rewriting the code in a computer program. You can think of it that way.

GARCIA-NAVARRO: Who would benefit from this technology? We got this call from Carolyn Strong.

STRONG: I am a carrier of hemophilia. And I chose not to have children because of that. It would have been awesome if the ability was in place to edit an embryo so that hemophilia was not a possibility for anybody's children.

GARCIA-NAVARRO: So for people who carry genetic diseases that can be inherited, this is, I guess, a big deal.

STEIN: Yeah. So that's the hope. The idea here is they - there are families that are plagued by some terrible genetic diseases. There's the long list of them - there's Tay-Sachs disease, cystic fibrosis, Huntington's disease, even some inherited forms of Alzheimer's disease. And the idea is that you could create embryos in the laboratory - sort of the way you do with in vitro fertilization, IVF - and then test them to see if they're carrying these defective genes that cause these diseases and then go in with this very precise editing tool and basically fix it.

Now, the caller's case - the short answer is maybe. And the reason for that is the genetics of hemophilia have some unique characteristics that make it more questionable about whether or not it would actually work.

GARCIA-NAVARRO: All right, genetic testing, though, has been around for a fairly long time. And parents who know they might pass along a mutation to their child can have their embryos tested already. How is this different?

STEIN: Yeah. so that's a very good point because the critics of this say, look, we don't need to do this. We already have ways to prevent these genetic diseases from being passed down in families. As you said, people can have their embryos tested before they are implanted in the womb to make sure they're healthy. Now in this case, we're talking about not testing embryos and only using the healthy ones, this involves fixing defective embryos to enable people to have healthy babies.

And the scientist involved in the research says that may be very helpful in certain circumstances where couples can't use the existing technologies. Or it could enable women to go through fewer cycles of IVF so they won't have to produce as many eggs and as many embryos to be able to have a healthy baby.

GARCIA-NAVARRO: What about the cost? I guess it always comes down to that. Claire Hahn (ph) wrote in on Facebook to ask, how economically accessible is this? Would it be something only available to the rich?

STEIN: Yeah, that's a really good question. And the short answer again to that one is, well, we don't know yet. Because this technology is so early, we really don't know how well it works, how safe it really is and then, in the end, if it does work and is safe, how expensive it will be. But that is one of the key concerns people raise about this sort of thing - that even if it does work and it is safe, it could be very expensive. And the concern is it would only be available to, you know, the well-off, rich people. And you could kind of create this two-tiered system where rich people can afford it and poor people can't.

GARCIA-NAVARRO: Here's something from MaryLue Bodenmiller.

BODENMILLER: If we're able to cure hereditary diseases, are we also going to use this technology to remove traits that we don't want, such as male-pattern balding or body modification for aesthetic reasons?

GARCIA-NAVARRO: All right, fear of designer babies - is that a real concern?

STEIN: Yeah, that's the big boogeyman in the room when we're talking about that. And the concern is that someday scientists may try to use these same techniques to do things like create genetically enhanced babies and do it for aesthetic purposes - you know, create babies that are taller or stronger or smarter or something like that. And that's the big fear about creating this world of genetic haves and have-nots, where some people who are considered to be genetically superior to other people. Now we're nowhere near being able to do that, but the concern is we may get there someday. And if that's the case, then we really need to have a huge societal debate about, - is that where we really want to go with this sort of thing?

GARCIA-NAVARRO: All right. Well, we had a little bit of pushback. We heard from Sean Ryan, who talked about fears about genetic engineering being overblown.

RYAN: The idea of managing our environment is not new. We do it already by choosing our partner and altering our children's surroundings. Engineering the genetic environment is a natural extension of this. What is important is that we be able to make these decisions freely with as much information about the consequences and limitations of this technology as possible.

GARCIA-NAVARRO: Is he right?

STEIN: Well, you know, that is one of the arguments I've heard. I've talked to scientists who are - say, look, you know, why are we so concerned about doing enhancements? We are already doing enhancements. We do plastic surgery, for example. I mean, we do things like develop drugs to make our memories better and things like that. I mean, aren't aren't those enhancements? So the big question is sort of where you draw the line and how far you want to go with this sort of thing. And again, that's something that, basically, we as a society have to debate and talk about to figure out if there's a place where we feel comfortable before we start moving ahead with that sort of thing.

GARCIA-NAVARRO: But I guess the key difference here is that these enhancements, potentially, would be passed on to our offspring. So they are not just something that we do to ourselves, but we would pass them on.

STEIN: Yeah, absolutely. That's the big line in the sand that had been drawn for years when it comes to science, that we should never make changes in the human DNA that could be passed down for generations. And there are really two big reasons for that. One is we could make some kind of mistake and introduce some new mutation that causes some new disease that then becomes a permanent part of the human genetic blueprint. And the other one is creating some sort of super-race that would be considered superior to everybody else.

GARCIA-NAVARRO: All right. When you talk like that, it makes me wonder who is regulating this technology. Is there any agency or committee or government body anywhere that is sort of looking at this stuff and trying to set guidelines?

STEIN: So that's a really good question. And right now in the United States, no one could try to create a baby using this technology. There's a couple of reasons for that. One is the National Institutes of Health will not fund any research involving human embryos because that's so controversial for so many reasons. Another reason is Congress has explicitly forbidden the Food and Drug Administration from even considering any kind of experiments like this. So that could never go forward in this country.

But it does vary from country to country. And there are other countries where this could move forward. In Great Britain, for example, they regulate this stuff much more closely, and they've approved some experiments that are similar to this that have not been approved in this country.

GARCIA-NAVARRO: You have covered this for a long time. And as I'm listening to you talk, I have two feelings, which is amazement and also a little bit of fear. I mean, how do you feel that you have spoken to so many scientists about this? I mean, where do you think this is going?

STEIN: So I think that the key issue is how the technology is used. If it's used for good to prevent terrible diseases and done responsibly, then I think you do a lot of good in the world. But there's a lot of concern that there are some rogue scientists out there who might try to push forward with this too quickly and rush it into the lab before it's ready. And that would be a real problem.

GARCIA-NAVARRO: That's NPR's Rob Stein. He's a correspondent and senior editor on NPR's science desk. Thank you so much.

STEIN: Oh, sure. Great to be here.


GARCIA-NAVARRO: Later this month - and this is something I'm very excited about - Americans will be able to look up into the sky and witness a total solar eclipse. What happens? How do you safely watch it? What's the best place to catch it? We want to hear your questions about this amazing event. So call in at 202-216-9217. Be sure to include your full name, contact info and where you're from - that number again, 202-216-9217. And we may use your question on the air.


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