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Autism — what we know (and what we don’t know yet)

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    "Why?"
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    "Why?" is a question
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    that parents ask me all the time.
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    "Why did my child develop autism?"
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    As a pediatrician, as a geneticist, as a researcher,
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    we try and address that question.
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    But autism is not a single condition.
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    It's actually a spectrum of disorders,
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    a spectrum that ranges, for instance,
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    from Justin, a 13-year old boy
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    who's not verbal, who can't speak,
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    who communicates by using an iPad
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    to touch pictures to communicate
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    his thoughts and his concerns,
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    a little boy who, when he gets upset,
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    will start rocking,
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    and eventually, when he's disturbed enough,
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    will bang his head to the point
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    that he can actually cut it open and require stitches.
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    That same diagnosis of autism, though,
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    also applies to Gabriel,
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    another 13-year old boy
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    who has quite a different set of challenges.
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    He's actually quite remarkably gifted in mathematics.
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    He can multiple three numbers by three numbers
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    in his head with ease,
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    yet when it comes to trying to have a conversation,
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    he has great difficulty.
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    He doesn't make eye contact.
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    He has difficulty starting a conversation,
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    feels awkward,
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    and when he gets nervous,
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    he actually shuts down.
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    Yet both of these boys
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    have the same diagnosis of
    autism spectrum disorder.
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    One of the things that concerns us
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    is whether or not there really is
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    an epidemic of autism.
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    These days, one in 88 children
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    will be diagnosed with autism,
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    and the question is,
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    why does this graph look this way?
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    Has that number been increasing
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    dramatically over time?
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    Or is it because we have now started labeling
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    individuals with autism,
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    simply giving them a diagnosis
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    when they were still present there before
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    yet simply didn't have that label?
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    And in fact, in the late 1980s, the early 1990s,
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    legislation was passed
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    that actually provided individuals with autism
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    with resources, with access to educational materials
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    that would help them.
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    With that increased awareness, more parents,
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    more pediatricians, more educators
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    learned to recognize the features of autism.
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    As a result of that, more individuals were diagnosed
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    and got access to the resources they needed.
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    In addition, we've changed our definition over time,
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    so in fact we've widened the definition of autism,
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    and that accounts for some of
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    the increased prevalence that we see.
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    The next question everyone wonders is,
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    what caused autism?
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    And a common misconception
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    is that vaccines cause autism.
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    But let me be very clear:
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    vaccines do not cause autism.
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    (Applause)
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    In fact, the original research study
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    that suggested that was the case
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    was completely fraudulent.
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    It was actually retracted from the journal "Lancet"
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    in which it was published,
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    and that author, a physician,
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    had his medical license taken away from him.
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    (Applause)
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    The Institutes Of Medicine,
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    The Centers For Disease Control,
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    have repeatedly investigated this
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    and there is no credible evidence
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    that vaccines cause autism.
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    Furthermore,
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    one of the ingredients in vaccines,
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    something called Thimerosal,
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    was thought to be what the cause of autism was.
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    That was actually removed from vaccines
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    in the year 1992,
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    and you can see that it really did not have an effect
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    in what happened with the prevalence of autism.
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    So again, there is no evidence
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    that this is the answer.
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    So the question remains, what does cause autism?
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    In fact, there's probably not one single answer.
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    Just as autism is a spectrum,
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    there's a spectrum of ideologies,
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    a spectrum of causes.
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    Based on epidemiological data,
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    we know that one of the causes,
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    or one of the associations, I should say,
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    is advanced paternal age,
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    that is, increasing age of the father
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    at the time of conception.
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    In addition, another vulnerable
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    and critical period in terms of development
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    is when the mother is pregnant.
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    During that period, while
    the fetal brain is developing,
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    we know that exposure to certain agents
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    can actually increase the risk of autism.
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    In particular, there's a medication, Valproic acid,
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    which mothers with epilepsy sometimes take,
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    we know can increase that risk of autism.
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    In addition, there can be some infectious agents
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    that can also cause autism.
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    And one of the things I'm going to spend
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    a lot of time focusing on
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    are the genes that can cause autism.
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    I'm focusing on this not because genes
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    are the only cause of autism,
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    but it's a cause of autism
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    that we can readily define
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    and be able to better understand the biology
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    and understand better how the brain works
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    so we can come up with strategies
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    to be able to intevene.
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    One of the genetic factors that we don't understand,
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    however, is the difference that we see
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    in terms of males and females.
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    Males are affected four to one compared to females
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    with autism,
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    and we really don't understand what that cause is.
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    One of the ways that we can understand
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    that genetics is a factor
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    is by looking at something called
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    the concordance rate.
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    In other words, if one sibling has autism,
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    what's the probability
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    that another sibling in that family will have autism?
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    And we can look in particular
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    at three types of siblings:
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    identical twins,
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    twins that actually share 100 percent
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    of their genetic information
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    and shared the same intra-uterine environment,
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    versus fraternal twins,
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    twins that actually share 50 percent
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    of their genetic information,
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    versus regular siblings,
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    brother-sister, sister-sister,
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    also sharing 50 percent of their genetic information,
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    yet not sharing the same intra-uterine environment.
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    And when you look at those concordance ratios,
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    one of the striking things that you will see
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    is that in identical twins,
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    that concordance rate is 77 percent.
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    Remarkably, though,
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    it's not 100 percent.
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    It is not that genes account
    for all of the risk for autism,
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    but yet they account for a lot of that risk,
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    because when you look at fraternal twins,
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    that concordance rate is only 31 percent.
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    On the other hand, there is a difference
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    between those fraternal twins and the siblings,
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    suggesting that there are common exposures
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    for those fraternal twins
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    that may not be shared as commonly
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    with siblings alone.
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    So this provides some of the data
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    that autism is genetic.
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    Well, how genetic is it?
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    When we compare it to other conditions
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    that we're familiar with,
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    things like cancer, heart disease, diabetes,
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    in fact, genetics plays a much larger role in autism
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    than it does in any of these other conditions.
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    But with this, that doesn't
    tell us what the genes are.
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    It doesn't even tell us in any one child,
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    is it one gene
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    or potentially a combination of genes?
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    And so in fact, in some individuals with autism,
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    it is genetic!
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    That is, that it is one single,
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    powerful, deterministic gene
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    that causes the autism.
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    However, in other individuals,
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    it's genetic, that is,
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    that it's actually a combination of genes
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    in part with the developmental process
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    that ultimately determines that risk for autism.
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    We don't know in any one person, necessarily,
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    which of those two answers it is
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    until we start digging deeper.
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    So the question becomes,
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    how can we start to identify
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    what exactly those genes are.
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    And let me pose something
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    that might not be intuitive.
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    In certain individuals,
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    they can have autism
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    for a reason that is genetic
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    but yet not because of autism running in the family,
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    and the reason is because in certain individuals,
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    they can actually have genetic changes or mutations
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    that are not passed down from the mother
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    or from the father
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    but actually start brand new in them,
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    mutations that are present
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    in the egg or the sperm
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    at the time of conception
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    but have not been passed down
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    generation through generation within the family.
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    And we can actually use that strategy
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    to now understand and to identify
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    those genes causing autism in those individuals.
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    So in fact, at the Simons Foundation,
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    we took 2,600 individuals
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    that had no family history of autism,
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    and we took that child and their mother and father
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    and used them to try and understand
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    what were those genes
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    causing autism in those cases?
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    To do that, we actually had to comprehensively
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    be able to look at all that genetic information
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    and determine what those differences were
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    between the mother, the father, and the child.
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    In doing so, I apologize,
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    I'm going to use an outdated analogy
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    of encyclopedias rather than Wikipedia,
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    but I'm going to do so to try and help make the point
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    that as we did this inventory,
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    we needed to be able to look at
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    massive amounts of information.
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    Our genetic information is organized
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    into a set of 46 volumes,
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    and when we did that, we had to be able to account
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    for each of those 46 volumes,
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    because in some cases with autism,
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    there's actually a single volume that's missing.
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    We had to get more granular than that, though,
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    and so we had to start opening those books,
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    and in some cases, the genetic change
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    was more subtle.
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    It might have been a single
    paragraph that was missing,
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    or yet, even more subtle than that,
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    a single letter,
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    one out of three billion letters
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    that was changed, that was altered,
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    yet had profound effects
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    in terms of how the brain functions
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    and affects behavior.
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    In doing this within these families,
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    we were able to account for approximately
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    25 percent of the individuals
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    and determine that there was a single
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    powerful genetic factor
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    that caused autism within those families.
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    On the other hand, there's 75 percent
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    that we still haven't figured out.
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    As we did this, though,
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    it was really quite humbling,
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    because we realized that there was not simply
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    one gene for autism.
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    In fact, the current estimates are
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    that there are 200 to 400 different genes
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    that can cause autism.
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    And that explains, in part,
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    why we see such a broad spectrum
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    in terms of its effects.
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    Although there are that many genes,
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    there is some method to the madness.
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    It's not simply random
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    200, 400 different genes,
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    but in fact they fit together.
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    They fit together in a pathway.
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    They fit together in a network
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    that's starting to make sense now
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    in terms of how the brain functions.
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    We're starting to have a bottom up approach
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    where we're identifying those genes,
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    those proteins, those molecules,
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    understanding how they interact together
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    to make that neuron work,
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    understanding how those neurons interact together
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    to make circuits work,
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    and understand how those circuits work
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    to now control behavior,
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    and understand that both in individuals with autism
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    as well as individuals who have normal cognition.
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    But early diagnosis is a key for us.
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    Being able to make that diagnosis
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    of someone who's susceptible
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    at a time in a window
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    where we have the ability to transform,
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    to be able to impact
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    that growing, developing brain is critical.
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    And so folks like Ami Klin have developed methods
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    to be able to take infants, small babies,
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    and be able to use biomarkers,
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    in this case eye contact and eye tracking,
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    to identify an infant at risk.
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    This particular infant, you can see,
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    making very good eye contact with this woman
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    as she's singing "Itsy, Bitsy, Spider,"
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    in fact is not going to develop autism.
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    This baby we know is going to be in the clear.
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    On the other hand, this other baby
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    is going to go to on to develop autism.
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    In this particular child, you can see,
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    it's not making good eye contact.
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    Instead of the eyes focusing in
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    and having that social connection,
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    looking at the mouth, looking at the nose,
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    looking off in another direction,
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    but not again socially connecting,
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    and being able to do this on a very large scale,
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    screen infants, screen children for autism,
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    through something very robust, very reliable,
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    is going to be very helpful to us in terms of being
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    able to intervene at an early stage
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    when we can have the greatest impact.
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    How are we going to intervene?
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    It's probably going to be a combination of factors.
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    In part, in some individuals,
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    we're going to try and use medications.
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    And so in fact, identifying the genes for autism
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    is important for us
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    to identify drug targets,
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    to identify things that we might be able to impact
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    and can be certain that that's really
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    what we need to do in autism.
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    But that's not going to be the only answer.
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    Beyond just drugs, we're going
    to use educational strategies.
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    Individuals with autism,
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    some of them are wired a little bit differently.
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    They learn in a different way.
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    They absorb their surroundings in a different way,
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    and we need to be able to educate them
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    in a way that serves them best.
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    Beyond that, there are a lot of individuals
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    in this room who have great ideas
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    in terms of new technologies we can use,
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    everything from devices we can use to train the brain
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    to be able to make it more efficient
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    and to compensate for areas in which
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    it has a little bit of trouble,
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    to even things like Google Glass.
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    You could imagine, for instance, Gabriel,
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    with his social awkwardness,
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    might be able to wear Google Glass
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    with an earpiece in his ear,
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    and have a coach be able to help him,
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    be able to help think about conversations,
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    conversation-starters,
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    being able to even perhaps one day
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    invite a girl out on a date.
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    All of these new technologies
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    just offer tremendous opportunities
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    for us to be able to impact
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    the individuals with autism,
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    but yet we have a long way to go.
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    As much as we know,
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    there is so much more that we don't know,
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    and so I invite all of you
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    to be able to help us think about
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    how to do this better,
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    to use as a community our collective wisdom
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    to be able to make a difference,
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    and in particular,
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    for the individuals in families with autism,
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    I invite you to join the interactive autism network,
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    to be part of the solution to this,
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    because it's going to take really a lot of us
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    to think about what's important,
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    what's going to be a meaningful difference.
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    As we think about something
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    that's potentially a solution,
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    how well does it work?
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    Is it something that's really
    going to make a difference
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    in your lives, as an individual,
  • 14:50 - 14:52
    as a family with autism?
  • 14:52 - 14:55
    We're going to need individuals of all ages,
  • 14:55 - 14:56
    from the young to the old,
  • 14:56 - 14:58
    and with all different shapes and sizes
  • 14:58 - 15:00
    of the autism spectrum disorder
  • 15:00 - 15:02
    to make sure we can have an impact.
  • 15:02 - 15:05
    So I invite all of you to join the mission
  • 15:05 - 15:08
    and to help to be able to make the lives
  • 15:08 - 15:09
    of individuals with autism
  • 15:09 - 15:11
    so much better and so much richer.
  • 15:11 - 15:14
    Thank you.
  • 15:14 - 15:18
    (Applause)
Title:
Autism — what we know (and what we don’t know yet)
Speaker:
Wendy Chung
Description:

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Video Language:
English
Team:
closed TED
Project:
TEDTalks
Duration:
15:35

English subtitles

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