Autism's future: Experts say it's genetics DAVID STEINKRAUS
In February, the British medical journal The Lancet formally retracted a 1998 study that linked autism to childhood inoculations with the vaccine for measles, mumps and rubella. The research by Andrew Wakefield was biased and unethical, said the council governing Britain's doctors. But if that explanation for autism is gone, what's left? In fact, there's quite a bit.
What's left are avenues of research that have nothing to do with Wakefield and never did. There is strong evidence for autism as a strictly inherited disorder, and research in California is pointing toward a tool that could detect autism in children not yet 2 years old.
Numbers and moms
A couple of months ago the Journal of the American Medical Association noted that autism remains a mystery, as does the increase in the occurrence of the disease. No single explanation works, said the article. What remains is the reality. Nationally, autism occurs in one of every 110 children.
In Wisconsin, autism occurs in about 13 of every 1,000 8-year-old boys and two of every 1,000 8-year-old girls. In whites the rate is higher, about 9 per 1,000 children versus about 4 in every 1,000 black children. This is according to a 2006 survey by the U.S. Centers for Disease Control and Prevention that included sites in 11 states. Racine and Kenosha counties were among the 11 in Wisconsin.
Every day, Candace Isetts-Williams, who is 43 and lives in Mount Pleasant, sees the face belonging to those numbers. Her 9-year-old son was diagnosed with autism at age 6, later than is typical. She believes the later diagnosis was because he was at a private school not equipped to deal with such children; teachers thought his problems were purely behavioral.
"My belief is he has genetic predisposition. I think it's something either I or his father gave to him. I think there's an environmental trigger," she said.
At first, people concerned about autism zeroed in on mercury, which was used as a preservative in many childhood vaccines, and a review found that children were being exposed to unsafe amounts of mercury. But by 2000, vaccines on the schedule of immunizations for children didn't contain mercury. Autism rates continued to increase.
Isetts-Williams said she believes in vaccines for children, but not necessarily so many in so short a time.
Shari Hardy, who is 38 and lives in Racine, has two children with autism. Her older son is 5; the younger will be 4 in July. And he was just diagnosed, she said, because the wait to have an expert examine a child is lengthy. The fact that she has two children with the disorder leads her to think that genetics must play a part, and that is the way experts are thinking.
Genes will tell
No one really has a complete explanation because autism is a disease we just don't know that much about, said John Sweeney, a professor and director of the Center for Cognitive Medicine at the University of Illinois at Chicago. In 2007, UIC was named one of five centers of autism excellence in the nation.
As to the vaccine-autism link, Sweeney said, no one, at least not among serious researchers, gave the report much credence when it was first published more than a decade ago.
"It's very hard to prove something's not true," he said. "Of course, the problem is a lot of people get vaccines at the time autism becomes apparent."
It is a coincidence in timing, said Eric Courchesne, a researcher at the University of California at San Diego, another of the centers of autism excellence. What happens, he said, is that the brain's language processing centers do not develop in the first months of life, so there is no apparent difference between a child with autism and one without it. In the second year of life those language centers mature rapidly. A child who had a vocabulary of only a few words suddenly works with hundreds or thousands. And then, just as the lack of linguistic ability in autistic child becomes apparent, the vaccinations are given.
We know resoundingly from studies that autism is inherited, said Dr. Robert Newby, an associated professor of neurology and pediatrics at the Medical College of Wisconsin. We know this because the family members of an autistic person can show mild versions of the same characteristics. "And the important thing to realize it that it's some but not all who show some characteristics to some degree."
There is not evidence for an environmental trigger working in combination with a genetic predisposition, Newby said. There is no environment common enough among autistic children to produce that conclusion.
Autism is not just a genetic disease but a very complicated one, scientists say, that undoubtedly involves many genes doing many different functions.
Genetic testing for autism recently took a step forward, Newby said. From being able to identify about two out of every 100 people with autism, a test may now find about seven.
Some of the genes will control brain development, some in regulating the brain's operation, Sweeney said. What they can become is targets for medications selectively prescribed to people with particular genetic profiles.
Brains will tell
Courchesne is working on a different angle. He and his wife, Karen Pierce, form two-thirds of a team at UC-San Diego that has been using magnetic resonance imaging of the brain to look for early signs of autism, such as the language processing mentioned above.
In earlier work, Courchesne and a colleague found that on average the brains of autistic children grow more than those of non-autistic children. In 2008, brain scans revealed how different language use can be.
"Developing kids and you and I predominantly use our left hemisphere," he said. "And what we're finding in autism, that is not the case."
Instead, autistic children use the right hemisphere. In very young children, Pierce said, some injury to one half of the brain induces the other half to rewire itself and try to carry out those missing functions.
Scans also showed that the greater the use of the right hemisphere, the better the language skills of the autistic person, Courchesne said.
The latest group of experiments took that search to younger ages, to children as young as 18 or 24 months, he said. In about two dozen children who had failed a screening test for autism and about two dozen children with typical brain development, the autistic children had distinctly different brain functions, he said. This work - which will be presented to the International Society for Autism Research in Philadelphia in May - has not been published and thus not reviewed by other researchers. The team is looking for a journal right now, Courchesne said.
But the differences they found occurred in more than a majority of children, Pierce said. And the possibility is a scan which would show autism before it is apparent and may even hint at how functional an autistic child may be.
The work needs to be replicated, of course, with more children, she said. And a test like this would never be the one factor for a diagnosis; it would be one of a suite of tools.
Listen and learn
"I think the concern about vaccines, I think people are just desperate to have an understanding of what's wrong and what they can do to prevent this," Sweeney said.
One of the best things parents can do is participate in medical investigations, he said, because that can lead scientists to home in on an explanation.
It does happen, Isetts-Williams said. When moms hear that diagnosis, they first wonder what they might have done wrong, how they could have caused the problem.
"And the answer I got was initially ‘No, it's nothing you did,' " she said. "I think you want an answer because that answer will make your child better."
What was appealing about Wakefield and doctors like him, Hardy said, is that they talked to parents and listened to them and wondered why autism happens.
Hardy said she still spends time searching for answers. Sometimes she will dive into research but then realize that her intense search for answers is pulling her away from her children.
"Unless it helps me help them it doesn't matter," she said. "I wish we could come together instead of arguing what it is, and try to help the kids."