Autism cluster found in Santa Clara County linked to parent education, not neighborhood toxins


By Lisa M. Krieger
Mercury News

Silicon Valley’s concentration of autism cases has triggered a spate of theories, from neighborhood contamination to a “geek gene.”

But a team of researchers from the University of California-Davis has found one factor that unites this and nine other California clusters of cases of the developmental disability: parental education.

College-educated parents of autistic children are more likely to fight for a diagnosis — and seek the state-funded services that accompany it — than less-educated parents, according to the team. Parents of children in these autistic “clusters” are also more likely to be older and white.

The cause of autism remains as mysterious as ever. But the dramatic correlation with parental education — seen not only in South Bay cases but also in the San Carlos-Belmont area of San Mateo County and parts of Los Angeles, San Diego and Fresno — eases fears that something specific is lurking in the soil or some families’ genes.

“It’s reassuring to me because I’m very health conscious,” said Pamela Kerman of San Jose, a marketing consultant who used her master’s degree in public relations to get help for her mildly autistic son, Nolan, 15.

She rejected his “borderline retarded” diagnosis when he was an infant because she knew he had a high intellect. And when teachers advised a watch-and-wait philosophy, she wrote a letter to the school superintendent. Only then was Nolan formally referred to a state diagnostic center, where he received an accurate diagnosis of the neurological disorder, which is characterized by social and communication difficulties

“As a parent, you have to be your child’s advocate. I encourage every parent, if they know something’s wrong, to take action; don’t wait,” said Kerman, who volunteers for a local chapter of the advocacy group Autism Speaks. “That’s one thing about me: When I make up my mind, I’m pretty determined,” she said.

Using patient records and mapping software, researchers with UC-Davis’ MIND Institute studied all 2.5 million births in California from 1996 to 2000.

The data, published today in The Journal of Autism Research, revealed 10 places where the diagnosis is more common than elsewhere in the state. In Silicon Valley, the Campbell-Santa Clara area had the largest clump of cases; while present elsewhere in the region, the number of diagnoses was less concentrated.

Cases were less common among Latino and less-educated families, researchers found.

The message for Silicon Valley families: “I don’t think you need to worry about anything in the neighborhood harming children,” said Irva Hertz-Picciotto, the project’s lead investigator.

“Rather, there
is an unevenness in how people are able to access care,” she said. “The California system of diagnosis is a passive one. Parents have to come to a regional center.”

A similar link between autism and education has been reported by researchers in several other nations. But in Denmark — which requires autism screening of all children — no difference was found among educational levels of parents.

A diagnosis of autism requires considerable advocacy by parents, who must navigate the complex world of pediatrics, psychiatry and autism experts. Once diagnosed, children gain access to all types of specialized services.

The research team dismissed the popular “geek gene” hypothesis, which suggests that the same genes that give a person gifted computational abilities might predispose their offspring to autism.

“It’s a clever idea, but the reality is that we don’t see a lot more clusters in Silicon Valley than in Sacramento or Southern California,” said Hertz-Picciotto.

“Genes are probably involved in autism, but it is likely a very complex interaction,” she said.

And while something in the general environment might trigger disability in a person with a genetic susceptibility, none of the hot spots found in the study shared any common toxins. “There are thousands of chemical or physical stressors that could potentially increase risk of autism,” said Hertz-Picciotto.

“This rules out local exposure to some agent,” said Carrie Molho, a psychologist with the Campbell-based San Andreas Regional Center, a state-funded autism center that collaborated on the study and provides services to patients.

“This is a very-respected study that shows that access to information, and the ability to seek a diagnosis, is critical,” said Santi J. Rogers of the San Andreas center.

He urged further study into the cause, not just correlations. “The number of kids with autism is still rising, and we don’t know why. This opens the door to further study.”

About the author


Jeffry John Aufderheide is the father of a child injured as a result of vaccination. As editor of the website he promotes well-educated pediatricians, informed consent, and full disclosure and accountability of adverse reactions to vaccines.

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