What's the supposed link between autism and gastrointestinal disorders?

[Orrex]

I can't figure it out, and I admit that I simply don't have the fortitude to slog through the results of a Google search. Can someone sum it up for me, or point me to a good source on it?

[TZ]

1. What I believe is going on is a genetic link

There have been theories that suggest that autism is caused by multiple gene defects-or chromosomal damage of some sort..What happens is the same kind of problem with the genetic pathway that leads to autism also has a pathway that leads to gastrointestinal disorders. In other words..the same group of genes that regulate the pathways that lead to autism also regulate some pathways that can lead to gastrointestinal disorders.
Is this about Wakefields nonsense that finding measles virus in the gastrointestinal tract can cause autism? Thats complete and utter tripe and as a doctor he should know better and is proof that he IS a quack.

Here's an article linking autism with muscle problems:
http://www.sciencedaily.com/releases/2008/04/080413161104.htm
Here's a bit of an article that describes the link and mentions the multiple gene/multiple pathway idea..
http://autism.about.com/od/medicalissuesandautis1/f/GIautism.htm

Leftish Brit will probably have some better sources on this, though

[Orrex]

2. Of course, everything Wakefield says is bullshit

And well-funded bullshit at that, IIRC.

The recent proliferation of the autism:GI-disorder linkage in Wooville made me wonder if something new had come to light or if this was just the latest recycling of the same tired mantra.

Your explanation about genetic pathway and multiple defects makes terrific sense, and it's more parsimonious than the woo's "there's a genetic predisposition to mercury-induced autism, and it's worsened by gastrointestinal disorders."

Thanks for clarifying!

[cosmik debris]

3. The only thing that is new is that the link was throughly refuted.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0003140

So the Autism Association promptly moved the goal posts. Go figure.

[LeftishBrit]

6. Agree - and the MMR vaccine in the UK NEVER contained mercury in any case.

Wakefield argued that the measles virus itself might predispose to autism and/or bowel disorders and/or specifically in children who already have bowel disorders - it was never very clear.

He did not have a control group, which is a cardinal sin in this type of research. Note that more recent studies, notably the one you quote, which did use controls, have failed to find any increased rate of measles virus in the guts of children with autism compared to others.

[realisticphish]

4. i feel ill when woos claim to be able to cure autism

that's about the only one i know ;)

[LeftishBrit]

5. Very unclear

There does seem to be an increased risk of gastrointestinal disorders in people with autism, though most people with either type of condition don't have the other.

By far the most likely explanation is some genetic association. It is also conceivable that prenatal environmental factors increase the risk of both, or that nutritional deficiencies resulting from very early onset bowel disorders affect brain development.

One thing that both autism and early onset bowel disorders have in common is increasing recognition. Personal example: I had Crohns disease from the age of 5, but it was not recognized till I was 16 because until the late 70s, children were supposed to be immune to such disorders! As with autism, childhood inflammatory bowel disorder is often thought to be on the increase (and the MMR has been blamed for that too!), but it's just as likely to involve changes in diagnosis.

Autism, though it frequently occurs on its own, is in fact associated with quite a number of medical conditions and syndromes: not just those involving the gastro-intestinal tract.

Until we know more about the exact genetic *and* neurological pathways involved in autism, it's going to be difficult to work out the reasons for any particular associations with the condition.

[TZ]

7. I also suspect

that because autism presents in such differeent ways, that there is not one root cause either. Its probably some complex interaction of genetics and environmental issues, as many diseases are.
But in Wooville they like to oversimply everything..just like they like to treat cancer like one simple disease....