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Wednesday, March 11, 2015

Genetic factors associated with autism also linked to higher intelligence

From “Rain Man” to the BBC’s “Sherlock Holmes”, popular culture portrays autistic people as having astounding abilities in areas of memory and deduction while lacking basic social skills.  While most people with autism spectrum disorder (ASD) are intellectually impaired, research supports the idea that they can have increased cognition in non-verbal areas.

But a study published yesterday by researchers from University of Edinburgh was the first to find a link between genetic factors for autism and higher intelligence in people without the condition.

ASD  is a developmental disability that causes behavioral, learning, and social communication disabilities. One out of 68 children are reported to have ASD in the U.S. according to the Centers for Disease Control and Prevention.

Up till now it was impossible to rule out that cognitive defects seen in autistic individuals were simply did not come from the environment, driven by the social and communication challenges of autism.

At this point, it is helpful to have a brief refresher on genetics: Our genes encode the information that tells our cells what to do. While everyone has the same genes, we have slightly different versions, or alleles, of the genes that help make us different from each other. These versions are passed on to our children.

Sometimes a single rare mutation can cause disease, such as in Cystic Fibrosis. But often it is more complex with mutations in different genes working together or with the environment to cause disease.

This more complicated version is the case for ASD. Last year it was shown that many gene alleles that are risk factors for autism are actually common in the general population but a combination are needed to cause autism.

The researchers wanted to see if these common risk alleles for autism were linked to cognition. They examined nearly 10,000 adults in the general population (i.e. without autism) and tested their cognitive performance on four tests as well as analyzing their DNA for alleles known to be associated with ASD.

They found a positive correlation between the presence of ASD risk-alleles and general cognitive performance. Specifically, those with the ASD-associated alleles did better on tests for verbal fluency, logical memory, and vocabulary.

The researchers suggest this finding will give insight into why some autistic people display incredible intelligence in certain areas and help understanding of how genetic factors for autism change brain function.

Clarke, J-K., et al. (2015). Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population. Molecular Psychiatry. doi: 10.1038/mp.2015.12

8 comments:

  1. Maybe if we can identify genetic factors associated with it it can help with diagnosis as well. There seems to be a large gray area in this subject, and a misdiagnosis can lead to problems in development of strategies for children learning and leading a happy and full life. Next up ADHD.

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  2. Very true. Interestingly, the researchers also looked at ADHD but found no association between genes linked to intelligence in this study.

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  3. This comment isn't related to this article, so if you don't want to post it here, that is fine. It is related to a different topic you have touched upon in the past.

    Recently, my spouse went to a faculty-meet-&-greet new administrators meeting and was told that the public puts academics into the same category as "bankers, lawyers, and arms dealers" meaning- the bad guy camp.
    My reply was, "Well, maybe that is just because everyone in the USA is carrying a lot of student loan debt and they resent it because they are starting adult life in debt, and in some cases, unemployed."
    Spouse said, "No, the public does not trust us. They are anti-intellectual, anti-science." He then went on to say that because of this public mistrust, politicians feel very comfortable slashing public university budgets (our current governor wants to start at 30% reduction).
    So my question to you, is there indeed a poll that shows academics are generally mistrusted by the public? And if so, why?

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    1. It seems like in general the public still trusts sceince: Pew research from 2014 found 79% of adults thought science made life easier. However 15% said science made life more difficult vs 10% in 2009. And there were large gaps in what the public believed about science vs scientists.

      The why is an interesting question. I think this comes both from scientists not communicating well with the public and even more so, the way science has become politicized and partisan: climate change is seen as a liberal issue and directly opposing industry/jobs and stem cell research or evolution are perceived as going against religion (also generally a Conservative issue). In support of this, A study published in 2012 using data from the General Social Survey found that while liberal trust of science has stayed the same from 1974 to 2010, conservatives has dropped from 48% to 35%(http://asr.sagepub.com/content/77/2/167.abstract).

      I heard an interesting idea (can't remember which TED talk) that people are less likely to listen logically to ideas that go against their "tribe" because the response from the brain is automatically an emotional one. It is therefore not hard to see how scientists with their statistics and dry manner can't penetrate an emotional response.

      Also there was an interesting Diane Rehm episode on "Why We Doubt Scientific Findings" where part of the blame is placed on scientists: for instance framing climate change as global warming allows the public to shrug it off when the South is hammered with snow storms (http://thedianerehmshow.org/shows/2015-03-04/why-we-doubt-scientific-findings).

      As far as how scientists are seen: a study in 2013 PNAS study found that scientists were seen as high-competence, low-warmth, lumped in with lawyers, CEOs, engineers, and accountants (but not arms dealers).

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  4. Why does there have to be a them and us? Seems like that type of thinking could lead to a bit of friction?

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    1. Are you referring to conservatives vs liberals or scientists vs the public? Either way, I think you are right and I am clearly not immune to this thinking. It does seem to be part of human nature to put ourselves into these tribes but as a result - it does create friction and can prevent honest communication - both political and scientifically.

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  5. It was just meant to be a broad statement not really directed at anyone in particular, but yes, everyone does it but is it really necessary? :-)

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  6. from pure observation i can tell there must be some link but in the past people (parents) were not diagnised with autism

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