Autism and the MMR vaccine

Posted on August 20, 2008  Comments (1)

Science Tuesday: Back into the hornets nest is a thoughtful follow-up post on the decision of a scientist to vaccinate his child.

Autism isn’t like tuberculosis, there’s not a bacteria that causes the disease. In fact,most researchers believe that “autism” is not a discrete disorder, rather “autism is a clinically defined pervasive developmental disorder with phenotypically diverse neuropsychiatric symptoms and characteristics. These manifest as a spectrum of social and communicative deficits, stereotypical patterns and disturbances of behaviour.”¹

If a particular trait’s heritability is 100% then the trait is due entirely to genetic variation, if the heritability is 0% then the trait is due entirely to environmental variation. By some estimates, heritability of autism spectrum disorders exceeds 90%

repeated studies have found that autism diagnoses continue to rise even after the removal of thimerosal from the vaccine.

Finally, when thinking about the environmental influences on autism, it’s important to explore the role of the environment on genetics. Many of the types of genetic changes that have been identified as causative in autism are indicative of some sort of DNA damage – DNA damage that may result from exposure to an environmental toxin. Many scientists, and I count myself in their number, feel that the recent autism ‘epidemic’ is due primarily to improved screening and diagnosis. In other words, prior to the 1980’s, many people suffering from autism were diagnosed as “slow” or misdiagnosed with another type of mental retardation. Unfortunately, there is no way to quantify this hypothesis.

This is one of the examples of what is so good about blogs. Great content that probably would not be available but through a blog.

Related: Scientists Reconsider AutismAutism, Science and Politicsposts on vaccination

One Response to “Autism and the MMR vaccine”

  1. Anonymous
    October 9th, 2008 @ 8:08 pm

    No one seems to be able to agree on what the exact cause is (if in fact it’s caused by a particular thing. From weak synapses to the immune system of their mothers, I’ve heard a lot of different explanations across the board. If I had any children myself, I’d get them vaccinated.

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