Wendy Chung: Could Genetics Hold The Answer To Curing Autism? Geneticist Wendy Chung describes what it's like to chip away at the mysteries of autism, and the excitement of uncovering tiny but critical clues.
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Could Genetics Hold The Answer To Curing Autism?

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Could Genetics Hold The Answer To Curing Autism?

GUY RAZ, HOST:

It's the TED Radio Hour from NPR. I'm Guy Raz. And on today's show - "From Curiosity To Discovery" and how one often leads to the other. But sometimes, discovery isn't really an endpoint. It's years of false starts that occasionally lead to a tiny breakthrough.

WENDY CHUNG: I guess I'm known as somewhat of a zebra hunter.

RAZ: This is Wendy Chung. She's a genetic researcher and a pediatrician.

CHUNG: You know, when people hear hoof beats, we say in medicine, you should usually think of horses rather than thinking of zebras. But many times families come to me after they've been to a lot of doctors for horses and haven't come up with the answers. And so they think there might be something more unusual or more esoteric.

RAZ: Wendy is actually more of genetic detective. And the case she's been trying to crack for more than 20 years - autism. Here's the opening from Wendy's TED Talk.

(SOUNDBITE OF TED TALK)

CHUNG: Why? Why is a question that parents ask me all the time. Why did my child develop autism? As a pediatrician, as a geneticist, as a researcher, we try and address that question. But autism is not a single condition. It's actually a spectrum of disorders - a spectrum that ranges, for instance, from Justin, a 13-year-old boy who's not verbal, who can't speak, who communicates by using an iPad to touch pictures to communicate his thoughts and his concerns. A little boy who when he gets upset will start rocking and eventually when he's disturbed enough will bang his head to the point that he can actually cut it open and require stitches. That same diagnosis of autism, though, also applies to Gabriel, another 13-year-old boy who has quite a different set of challenges. He's actually quite remarkably gifted in mathematics. He can multiply three numbers by three numbers in his head with ease. Yet, when it comes to trying to have a conversation, he has great difficulty. He doesn't make eye contact. He has difficulty starting a conversation - feels awkward. And when he gets nervous, he actually shuts down. Yet, both of these boys have the same diagnosis of autism spectrum disorder. One of the things that concerns us is whether or not there really is an epidemic of autism. These days, 1 in 88 children will be diagnosed with autism. And the question is - has that number been increasing dramatically over time? Or is it because we have now started labeling individuals with autism - simply giving them the diagnosis when they were still present there before? The next question everyone wonders is, what caused autism? In fact there's probably not one single answer just as autism spectrum there's a spectrum of etiologies - a spectrum of causes.

RAZ: So the thing to know about Wendy Chung is that she never set out to crack autism. She was a genetics researcher who sort of stumbled upon a realization.

CHUNG: I think the realization came to me looking or came to several of us that genetics at least could be one of the factors in autism. It didn't necessarily mean that all children with autism had an underlying genetic cause but that it could be the genetic cause.

RAZ: And that theory tested early in her career when she met a little girl named Nika.

CHUNG: In that particular case Nika's parents came to me many, many years ago having done, you know, the best they could to try and understand what was going on with their daughter and why she wasn't developing the same as other children.

RAZ: For example Nika couldn't speak. She clearly had significant disabilities including autism.

CHUNG: But not any one thing that looked particularly unique. She looks like a beautiful healthy child otherwise. But she clearly had something going on with her brain.

RAZ: And on top of that she'd get seizures - lots of them on a daily basis.

CHUNG: She didn't have any family history of a similar condition. So there wasn't anything for us to think that it was something clearly running in the family.

RAZ: And so Wendy Chung began to wonder what if the source of Nika's disability was a genetic mutation and what if you could identify that exact gene?

(SOUNDBITE OF TED TALK)

CHUNG: In certain individuals they can actually have genetic changes or mutations that are not passed down from the mother or from the father but actually start brand-new in them. Mutations that are present in the egg or the sperm at the time of conception but have not been passed down generation through generation within the family. So in fact at the Simons Foundation we took 2,600 individuals that had no family history of autism and we took that child and their mother and father and used them to try and understand what were those genes? To do that we actually had to comprehensively be able to look at all that genetic information and determine what those differences were between the mother, the father and the child. In doing so...

RAZ: So as Wendy goes on to explain every single human cell is made up of exactly 46 chromosomes and if any one piece of those 46 chromosomes that make up the billions of cells in our bodies is out of balance it can have a huge effect on the way our brains function. And so in the case of Nika, the girl who was diagnosed with autism as a toddler, Wendy was able to map out her genetic information to try and figure out what caused her brain to function in the way it did.

CHUNG: I still remember when we did that the only reason we were able to find the cause - it was literally like looking for a needle in the haystack, was because we saw one single letter out of 3 billion alphabet letters we saw one single letter for Nika that was different from her mom and different from her dad.

RAZ: Wow.

CHUNG: Something we knew wasn't inherited from either one of them and suddenly when we looked at that particular place, that one letter that was different, we saw that it affected this gene called called snap25.

RAZ: Wow.

CHUNG: Which essentially affecting all different areas for Nika's brain as well as causing her seizures.

RAZ: You were able to discover that one single genetic mutation and identify it and know that's where it came from.

CHUNG: That's exactly right. Knowing that this was the problem meant that we could start the journey to trying to figure out how to fix it.

RAZ: But I mean that journeys, that process of trying to fix it - I mean that could take decades.

CHUNG: I think there are pieces of it we're cracking every day. In terms of understanding the complexities of the human mind I don't know we'll ever truly understand it.

RAZ: Yeah, I mean do you sort of think about what you do as trying to crack a code?

CHUNG: Oh absolutely. So, the first gene we identified for human disease took me eight years. Last gene that we identified for human disease took eight days and it's really remarkable in terms of how quickly we can move forward. I think it's that puzzle that I'm so obsessed with is, at least from the genetic point of view, trying to crack that code about what those genes are and trying to put that into a massive, you know, puzzle in terms of how those genes fit together, how those proteins fit together, how those neurons fit together, what the different parts of the brain do and why they're different in some individuals.

RAZ: Yeah, I mean do you ever come home at night and just think, I may never figure this out - like over the course of my career it may never happen.

CHUNG: Well, I think, you know, the stark reality is for many of us we realize that there's only so much that we can do and mysteries like this really massively complex feats you have to be able to break down in pieces. But I think the humbling part of this is that the mind is just wonderfully, beautifully complex and we will start to understand parts of it. So there are just amazing opportunities we have to study this - like we didn't at generation ago. But even still it's - we're just wonderfully complex human beings and appreciating all of that is awe-inspiring.

RAZ: Wendy Chung is a genetic researcher and a pediatrician. You can find out more about her groundbreaking work and see her full talk at Ted.com.

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