Paul Knoepfler: What Are The Unintended Consequences Of Human Gene Editing?

Sep 15, 2017

Part 3 of the TED Radio Hour episode Future Consequences.

About Paul Knoepfler's TED Talk

New gene editing tools hold a great deal of promise, but biologist Paul Knoepfler says we should be cautious. He warns altering DNA can have dire consequences, including a new form of eugenics.

About Paul Knoepfler

Paul Knoepfler is a biologist and a professor at UC Davis School of Medicine. His research examines stem and cancer cells including new genetic modification technology's capacity to transform these cells.

He is the author of GMO Sapiens: The Life-Changing Science of Designer Babies and runs the popular science blog, The Niche.

Copyright 2017 NPR. To see more, visit


OK. So Juan Enriquez is saying that this is all superpromising and exciting, and we could actually eliminate disease. And we could create...


RAZ: ...You know, future humans who are immune from these horrible afflictions that haunt us. And that all seems pretty awesome, right?

KNOEPFLER: Well, you know, I've kind of taken it upon myself to try to get out there in the public and talk about how this technology could go wrong.

RAZ: This is Paul Knoepfler.

KNOEPFLER: I'm a professor at UC Davis School of Medicine.

RAZ: Paul spends a lot of time researching new gene-editing tools like CRISPR, which basically allows you to cut and paste genes together, and how that technology might have unintended consequences down the road.

KNOEPFLER: Genetics is this interwoven, complex universe unto itself where you touch in one area, but you touch on there and there can be reverberations. You can change other genes and you can have consequences you might not like. And so every time you make one change, you might end up with a host of sort of associated sort of satellite changes as well.

RAZ: Paul described what the future of gene editing could look like when he gave his talk on the TED stage.


KNOEPFLER: Let's pretend it's the year 2030 and you're a parent. You have your daughter, Marianne, next to you. And in 2030, she is what we call a natural because she has no genetic modifications. And because you and your partner consciously made that decision, many in your social circle, they kind of look down on you. They think you're, like, a luddite or a technophobe. Marianne's best friend, Jenna, who lives right next door, is a very different story. She was born a genetically-modified designer baby with numerous upgrades. The scientists that Jenna's parents hired to do this for several million dollars introduced CRISPR into a whole panel of human embryos. And then they used genetic testing and they predicted that that little, tiny embryo, Jenna's embryo, would be the best of the bunch. And now Jenna is an actual, real person. She's sitting on the carpet in your living room playing with your daughter, Marianne. And your families have known each other for years now, and it's become very clear to you that Jenna is extraordinary. She's incredibly intelligent. If you're honest with yourself, she's smarter than you. And she's 5 years old.


KNOEPFLER: She's beautiful, tall, athletic. And the list goes on and on. And, in fact, there's a whole new generation of these GM kids like Jenna. And so far it looks like they're healthier than their parents' generation and your generation. They're immune to a host of health conditions including HIV-AIDS and genetic diseases. It all sounds so great, but you can't help but have this sort of unsettling feeling, a gut feeling that there's something just not quite right about Jenna. You've had the same feeling about other GM kids that you've met. You were also reading in the newspaper earlier this week that a study of these children who were born as designer babies indicates they may have some issues like increased aggressiveness and narcissism, but more immediately on your mind is some news that you just got from Jenna's family. She's so smart, she's now going to be going to a special school, a different school than your daughter, Marianne. And this has kind of thrown your family into a disarray. Marianne's been crying, and last night when you took her to bed to kiss her goodnight, she said, Daddy, will Jenna even be my friend anymore?

RAZ: This sounds totally freaky. I mean, you are saying that within 15 years, people could be designing their own babies, like - like, free of genetic diseases and - and even choosing traits. You know, which in some ways sounds pretty good, but - but as you point out, it could create enormous problems as well.

KNOEPFLER: Yeah. You know, it can seem very positive. It can seem like a goal we should go for.

RAZ: Yeah.

KNOEPFLER: You know, who - who can argue with someone being healthier and, you know, perhaps having certain traits that are broadly perceived as quote-unquote "better?" But along with those things that society might perceive as desirable traits, you know, perhaps they would be more aggressive or perhaps they might develop some kind of unexpected disease later in life, and so at those kinds of levels we can't always anticipate what the consequences will be. There's also a concern if you imagine that kind of future in 15, 20, 25 years. There could be these sort of genetic class distinctions, right? There will be people who could afford to genetically modify their children, and then there will be those of us who couldn't. And I think there could be substantial negative consequences from that in terms of social justice and instability in society. And so as much as that, you know, hypothetical genetically-modified, designer-baby Jenna of the future might seem like a wonderful thing to potentially pursue technologically, for me it seems very risky.

RAZ: Yeah. I mean, it could be great if we could eliminate diseases, like, you know, like, like Huntington's disease or cystic fibrosis which are just horrible diseases. But, you know, why - why would we stop there? I mean, you could imagine people would say, well, let's deal with Down syndrome. Let's deal with cleft lips. Let's deal with all kinds of, you know, debilitating deformities or whatever.

KNOEPFLER: It's very tricky because again you can find yourself kind of slipping towards changing traits, too. Like, you might try to prevent a neurological disease that's horrible but at the same time you've - hey, you know, successfully prevented that. That's fantastic. What if you're sort of in this weird, unexpected outcome where that kid is super smart as well, way smarter than anybody else? And then, you know, what if someone else wants to try to repeat your experiment not to get rid of that neurological condition but to make smarter people? And one thing I've learned in science over the years is oftentimes these experiments we do, they don't turn out quite the way we think they're going to.

RAZ: In just a minute, Paul Knoepfler's ideas on how we should be regulating this new technology and what it can mean for the future if we don't. Stay with us. I'm Guy Raz, and you're listening to the TED Radio Hour from NPR.


RAZ: It's the TED Radio Hour from NPR. I'm Guy Raz. And on the show today, Future Consequences, how the things we decide to do today will shape everything about tomorrow. And when it comes to things like gene editing, biologist Paul Knoepfler thinks the best step forward might be to take a step back.

KNOEPFLER: And, in fact, I've been in favor of a moratorium on the use of CRISPR in reproduction, you know, in actual human reproduction. So just to be a hundred percent clear, I don't want to have any kind of negative impact on CRISPR research in the lab at all. And CRISPR used some things like gene therapy, which is not heritable. I'm totally in favor of that. But I do think we should say, you know, if we're going to be using CRISPR in human embryos with the goal of making permanent genetic changes that will be passed on to future generations, right now we should not go down that path. But even if we did all agree on a moratorium, you know, is that only going to be in one country? What happens in other countries? And - and it's very hard to prevent something from happening when you have a very exciting technology.

RAZ: Yeah.

KNOEPFLER: And it has such power.


KNOEPFLER: We know from Darwin, you know, if we go back two centuries, that evolution and genetics profoundly have impacted humanity, who we are today. And some think there's, like, a social Darwinism at work in our world and maybe even a eugenics as well. Imagine those trends, those forces with a booster rocket of this CRISPR technology that is so powerful and so ubiquitous. And, in fact, we can just go back one century, to the last century, to see the power that eugenics can have. So today I see a new eugenics kind of bubbling to the surface. It's supposed to be a kinder, gentler, positive eugenics. Different, you know, than all that past stuff. But I think even though it's focused on trying to improve people, it could have negative consequences. And it really worries me that some of the top proponents of this new eugenics, they think CRISPR is the ticket to make it happen.

RAZ: I - I'm not a religious person, but I'm really troubled by the idea that we - we take over a natural process that - that nature essentially stops in humans. And humans, we become God.

KNOEPFLER: You know, I - I've thought about that too, and I feel like as much as, you know, the human race is amazing, right, and we have these amazing brains and we've come so far technologically-speaking. Sometimes our technologies race ahead of our ability to really place them in a wise context and know what to do or not to do with the technologies, and, you know, we end up with atomic weapons and things like that. And I don't think it's - it's too outlandish to say using CRISPR in humans in a heritable manner would be akin to kind of, like, playing God.

RAZ: I mean, no one's going to just stop researching this. No one's going to stop looking at the possibility of it because it is inspiring. It is full of wonder - idea that you could stumble upon or come upon the technology to do this. I mean, I understand why somebody would want to pursue that 'cause it's - it's wondrous.

KNOEPFLER: Yeah. You know, it may be that it's not, you know, yes or no. It may be just that we are as a collective society going to be going down that path whether some of us like it or not. And, in fact, I don't think that we can really just say stop. You know, I think people will use this, and so it just means we need to be having more of these kinds of conversations like we're having right now trying to anticipate what are going to be the consequences. And we should be trying to talk about both the exciting sides of it and also the sides that maybe have a darker edge to them as well.

RAZ: Biologist Paul Knoepfler. He also writes a science blog called The Niche. You can hear his full talk at

(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.