Saturday, 07 July 2012
A study, reported on in the New York Times today, confirms what many of us had deduced previously: that autism causes are at least as much environmental as genetic. Nobody knows what the cause or causes are, of course. Meanwhile, autism-cure dollars have all been going for studies focusing on the genetic basis of the situation, while environmental factors such as vaccines, chemicals like BPA, and drugs have hardly been investigated.
The new study tracked 192 pairs of identical and fraternal twins where at least one of the twins has the classic form of autism, with extreme social withdrawal. The researchers found autism in the other twin in 77 percent of pairs of male identical twins and 50 percent of female identical twins. There was a correlation for fraternal, too, of 31 percent for males and 36 percent for females.
But was the autism caused by genetics or environment? After all, twins usually share the same environment.
Mathematical modeling provided the surprise for researchers. It showed that only 38 percent of the twin autistic pairs could be linked to genetic factors. And it found shared environmental factors that appeared of concern in 58 percent of the cases.
“I think we now understand that both genetic and environmental factors have to be taken seriously,” said Dr. Joachim Hallmayer, lead author of the study, a researcher at Stanford. The study will be published in the November issue of Archives of General Psychiatry.
I am so glad to hear this study result. The scientific establishment’s history of chasing only genetic factors hasn’t been logical.
Here’s why. We are in an autism epidemic, with one in 100 kids, roughly, now identified as autistic. Perhaps you think there’s better diagnosis going on than there used to be, accounting for the apparent increase in numbers. If that were the case, there would be a “hidden horde” of people in middle age and older who are moderately or severely autistic, and they would be undiagnosed. Do you see such people around? At the rate of one in 100? They’d stick out in a crowd. I don’t see them, either.
Now that we’ve established there’s an epidemic, perhaps we can agree that epidemics can’t have a genetic cause because genetics don’t change very fast. Why is the generation born in the 1990s and later so seriously affected, and previous generations aren’t? Surely there weren’t zillions of spontaneous mutations beginning in 1990 and not before.
Therefore, this autism epidemic has to have environmental causes. It also has genetic causes, I am sure of that, looking at my own family. But there are plenty of families with autistic kids who have no autistic relatives at all. In those cases, the environment is surely 100 percent to blame.
Now, there is one environmental study I’m dying to see: a comparison of incidence of autism in vaccinated vs. unvaccinated populations. This study wouldn’t be particularly hard to do, since there are more and more unvaccinated people to choose from, and there’s a large home-birth medical practice in Chicago that steers patients away from vaccines. But it takes someone with the research dollars to do it, and that doesn’t include concerned parents of autistics such as me.
I think the researchers are afraid to do this study. But maybe now, after this twin study, it will be more likely.