New study to explore causes of autism

Jennifer Pinto-Martin Candace diCarlo

According to a recent report from the Centers for Disease Control and Prevention one in 150 children in this country is affected by autism. Is the disorder on the rise? “It just seems like that” says Jennifer Pinto-Martin, a professor in Penn’s Nursing School and director of the Center for Autism and Developmental Disabilities.

Pinto-Martin, who was involved with the CDC study, the most comprehensive ever, says it’s not that the disorder is increasing in prevalence but that as a nation we are doing a better job of recognizing autism and getting children in for evaluation. “There’s been a sea change in the last 20 years,” says Pinto-Martin. “because informed parents and teachers have brought it to the forefront.”

The rate also seems unexpectedly high, she says, because of a shift in diagnosis criteria to a wider spectrum that includes children with social and communication skills severely impaired by autism, those with the milder form of the disorder known as Asperger’s Syndrome and others in between.

While the percentage of children with autism may have held steady, Pinto-Martin says there is new recognition of the magnitude of this public health crisis. “These kids can’t survive in school without appropriate intervention and intervention services are not available to the extent they need to be,” she says. “This is a cry for improved financing.”

This spring the School of Nursing will join five other sites across the nation in a new five-year CDC-funded study Pinto-Martin hopes will lead to a better understanding of the causes of autism.

“We know it’s strongly genetic, but not purely,” says Pinto-Martin. Beyond family history, scientists are eager to find an environmental cause, though most no longer believe childhood vaccines are the culprit. “A huge amount of research dollars has been spent on the vaccine hypothesis,” says Pinto-Martin. “In my mind it’s an example of science gone bad because the information spread so quickly on the Internet and parents were so desperate for an explanation it took on a life of its own. There have been at least 50 studies now and no good peer-reviewed epidemiological study has supported the hypothesis. And yet it’s still not dead.” Adding fuel to the fire, says Pinto-Martin is the fact that symptoms emerge at the same time children are getting vaccines, leading to a natural, if spurious, association in the minds of parents.

For the study, 2,700 children between the ages of 2 and 5 will be evaluated, 900 already diagnosed with autism, 900 with other developmental disabilities (such as Attention Deficit Disorder) and 900 who are developing typically. All the children—150 in each category per center—will come in for a day of evaluation, which will include behavioral screening as well as the collection of cheek swabs and blood samples.
The researchers will also gather information from parents, including history of pregnancy (fevers, maternal infection, fish consumption, etc.), exposures during pregnancy, reproductive history and autoimmune problems.

As anxious as parents are for answers, Pinto-Martin isn’t expecting a magic bullet. “Right now we know nothing,” she says, “and I think there are many triggers to suspect.” But if there was an environmental cause, like a heavy metal or toxin, that could be pinpointed, she says, scientists would have picked it up by now. “There is some suggestion that bad things happening during pregnancy may be part of the answer,” she adds, “but it’s hard to tease out one thing.”

Pinto-Martin says she hopes the parents recruited for the study will recognize that “it’s a long road and we’re unlikely to find a single cause.” She’s hopeful that the study will give them some reassurance, though “in the sense that it’s not anything they did or didn’t do, it’s not something a parent should feel blamed for.”

Pinto-Martin is also involved in an early training initiative to give pediatricians the tools they need to identify autism early on. “If you don’t screen every kid for it routinely you don’t see it until school,” she says. “Early identification is critical. The earlier they’re diagnosed the better kids do down the line.”

Originally published on March 1, 2007