Autism and Controversy: Bring it on

“Teach the Controversy!” is the title of a post on Pharyngula about a certain college’s insistence on the teaching of creationism in courses in biology, the Bible, and other areas—–vs. teaching something more “controversial” such as evolution. The question of “what causes autism” has yet to be played out in the courtroom, though mention “mercury” or “vaccines” (and related “cures” such as chelation) in the same context as autism and rancourous debate may well ensue: Autism has its controversies, for sure.

Studies providing evidence about the genetics of autism can arouse especial ire among some proponents of an environmental cause for autism. Neurologist Steven Novella who teaches at the Yale School of Medicine, writes two recent studies on the genetics of autism in Autism Genetics and Controversies on NeuroLogica Blog. The first study, published in Nature Genetics, found that “there are 5-6 major genes and about 30 other genes that have alleles that are strongly associated with the risk of developing autism”; the second study, published in Science Magazine, “found that the rate of mutations in certain genes is much higher is sporadic cases of autism (about 10 times the rate in healthy controls) compared to autism where there is a prior family history (about twice the rate of healthy controls).” Writes Dr. Novella:

Of course, these two studies are just the most recent bits of evidence in a very large and growing body of scientific evidence clearly demonstrating that ASD has genetic roots. However, the exact relationship still needs to be elucidated. First it needs to be understood that ASD is likely not a single disease but rather a groups of diseases possibly with various underlying causes. Neurological disorders, like ASD, are determined by which part of the nervous system is not working – not by the mechanism of damage. So there may be multiple different causes resulting in the same populations of nerve cells or structure(s) in the brain malfunctioning, and therefore the signs and symptoms will be the same or similar.

So, it is possible that a subset of ASD is caused by genetic variants or mutations, but that another subset has a distinct cause – inflammatory, environmental, developmental, etc. It is also possible that certain genetic types are predisposed to environmental triggers. However, non-genetic causes or contributors to ASD remain highly speculative and controversial. Although the press tends to focus on these issues, including a lengthy article in the current issue of Discover magazine, the fact is that evidence for any particular environmental cause remains scant.

Perhaps the most controversial aspect of this debate has been the claim by some that ASD is caused by vaccines. First it was blamed on the MMR vaccine itself, and than later on thimerosal, a mercury based preservative in some childhood vaccines (although removed several years ago). So far the evidence is strongly against any association between vaccines and autism, but this notion has its dedicated adherents, including, of course, the anti-vaccine crowd.

As I have noted before, I am no scientist but an “autism mother on her soapbox.” As a fellow autism parent and blogger (and doctor) recently commented, this blog has taken me “Out of the icebox and into the fire.” In view of some of the discussions here about the growing dominance of a certain autism organization in the mass media portrayal of autism, on the causes of autism and on whether or not there is an epidemic of autism, I guess I have indeed blogged my way into a few autism controversies, and therefore appreciate the views of scientists like Dr. Novella all the more.

In the face of (quoting Dr. Novella) “campaigns of misinformation, conspiracy mongering, and pseudoscience,” we need to keep asking the hard questions and to keep courting—-keep teaching—controversy: Who is given the opportunity to represent autism in research about autism and in legislation about autism? What is going on in autism research? Who is saying what about autism and to what end?

A little controversy can be a useful thing when it comes to autism. Bring it on.