Cambridge University Autism Expert Highlights Flaw In Reports of New Autism Paper

A new paper on the causes of autism announced today is seemingly being misreported in a Science Daily news release originating from Eurekalert: Gene Variant Associated With Both Autism And Gastrointestinal Dysfunction – ScienceDaily (Mar. 2, 2009).

Cambridge University Autism expert Professor Simon Baron Cohen is already on record explaining why autism has an environmental and not solely genetic cause:-

Autism Not Genetic – Says Expert Professor Simon Baron Cohen

The authors of a new paper just published in the journal Pediatrics are being reported as suggesting that autism and gastrointestinal disorders occur together solely as a result of an individual’s genetic make-up. However, this is contrary to the results and work of the lead author of the paper, Dr Pat Levitt of the University of Southern California.

A presentation of work by Dr. Levitt during the Autism and the Environment Workshop conducted by the US Institutes of Medicine in April 2007 is worthy of review.  On page 31 of the report of those proceedings Dr. Levitt states that the variant of MET, SP1, associated with ASD, is affected in its expression by environmental toxins.

Dr Levitt has researched the relationship between MET genetic polymorphism and autism. The MET polymorphism occurs in almost 50% of the population. It is clear factors other than genetics play an important, even dominant, role in determining which children have GI problems that are associated with the MET polymorphism.

So, contrary to the news releases that the MET gene finding shows that the correlation between ASD and GI disease is purely genetic, the work on MET variants and autism shows just the opposite, that susceptibility factors such as the common variants of the MET gene, make individuals more susceptible to environmental toxins.

The new paper is Distinct Genetic Risk Based on Association of MET in Families With Co-occurring Autism and Gastrointestinal Conditions. Pediatrics, 10.1542/peds.2008-0819, Daniel B. Campbell, Timothy M. Buie, Harland Winter, Margaret Bauman, James S. Sutcliffe, James M. Perrin, Pat Levitt.

Eurekalert is a service provided free to journalists by the American Association for the Advancement of Science and has no independent external unbiased and objective control or scrutiny over the information published by the Eurekalert service to the media.   Funders of AAAS and Eurekalert include GlaxoSmithKline, Merck & Co Inc, Johnson & Johnson Pharmaceutical Research and Development, Pfizer Inc and Roche Pharmaceuticals.

Dr. Pat Levitt is quoted in a 2006 press release from Vanderbilt University reporting the same research [emphasis added]:

In the current study, Levitt and colleagues analyzed the MET gene in more than 700 families who had at least one child with autism. They found that children with autism commonly had a specific change in the sequence of the promoter region of the gene, the part of the gene that regulates the amount of MET protein produced.”

‘This variant is in the part of the gene that controls how much of the gene gets expressed…kind of like ‘volume control’ on a stereo,’ Levitt says.

People with two copies of this variant were 2.27 times as likely to have autism as the general population. Individuals with only one copy were also at higher risk (1.67 times) than those without the variant.

“This is a relatively common variant, seen in about 47 percent of the population,” Levitt says. “So why doesn’t everybody have autism?”

That speaks to environmental and other genetic contributions, Levitt says.

“Genes create a vulnerability that then gets coupled with some environmental disturbance — but right now, we don’t have any idea what those factors might be.”

For a useful discussion of the topic, see the comments on this blog:-

2 Responses

  1. the Science Daily article cited above in no way suggests autism and GI dysfunction are “solely” a result of genetic causes. Thus neither the Science daily article nor this research “contradicts” any prior work or statements by the lead author, as suggested. Clearly, environmental influences could cause abnormal gene epxression and cause one or both disorders. This work simply provides a mechanism for why the two are often seen together. This article on the other hand IS misleading.

    Of course, the sooner people stop thinking genes are everything the better. Your environment shapes the expression of your genes! Period. But please stop acting like the cause of autism has to be one or the other. This isn’t a game of picking sides.

    [ED: You should read “Autism Not Genetic – Says Expert Professor Simon Baron Cohen“]. The Science Daily article is misleading and misrepresents the work of the lead author. Fortunately, accurate information can be found in this posting.

  2. I read the article in ScienceDaily and they do not say that it is based just on genetics — there is a principle in biology that the environment has the potential to regulate genetic expression…Might want to read that article over again….or another article out of another university…..MET Gene Linked To Autism, GI Problems In Children…Vanderbilt Medical Center….…..HEIRS Health & Home

    [ED: The article in science daily is all about genetics. It is all it mentions. You are welcome to your point of view but what you cannot point to is any mention in the article of Levitt’s work linking autism and GI problems to environmental causes – go on – show us where it is mentioned – that’s right – nowhere. There is no mention at any time of Dr Levitt’s research linking autism to environmental causes. That is a significant journalistic oversight and gives the reader the understanding that GI problems and autism have no connection other than genetic and no environmental cause. Bearing in mind how desperate some folks are to pretend autism has no environmental causes, this is just one more article and news release intended to mislead the world.

    And if you look at the links to other articles on that page here are their headlines:

    Autism Risk Higher In People With Gene Variant (Jan. 11, 2008)
    Infidelity Gene? Genetic Link To Relationship Difficulties Found (Sep. 2, 2008)
    Researchers Identify First Gene Variant That Appears To Increase Risk Of Autism In Significant Portion Of The Population (Apr. 1, 2004)
    Gene Linked To Autism In Families With More Than One Affected Child (Oct. 22, 2006)
    Study Links Regions Of Two Chromosomes To Susceptibility For Type Of Autism (June 9, 2005)]

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