Understanding the spectrum

Whenever Dr. Lisa Benaron reads a news story trumpeting a revelation about autism, she braces herself for a letdown.

Benaron is medical director at Far Northern Regional Center, a referral point for individuals with developmental disabilities. North State pediatricians often send patients to her for diagnosis, because autism spectrum disorder (ASD) falls squarely within her realm of expertise (in fact, she’s written a book on the subject: Autism in the Biographies of Disease series published by ABC-CLIO.)

“Each time something comes out, it comes out under this banner like, ‘This is the answer,’” she said, “and it continues to be, ‘This is [just] another volley in the number of studies that are trying to answer this question.’”

Case in point are two recent reports that drew splashy headlines—one regarding the prevalence of autism, the second regarding the cause.

The first study, conducted by scientists at Penn State, attributes a great proportion of rising autism rates to changes in the way the condition is identified rather than greater prevalence. By analyzing information culled by tracking children in special education classes, researchers determined that around two-thirds of the rise in autism diagnoses between 2000 and 2010 was due to the widespread reclassification of students from intellectual disability to autism.

The Penn State researchers’ summation was more technical and nuanced than the media coverage, which latched onto the idea that the increase in prevalence is due to changing diagnoses.

Nonetheless, the study leaves a distinct impression that cuts against common wisdom and well-known statistics—namely that autism has become more common, from 1 in 150 children to 1 in 60 during this research period.

“I just don’t think that there’s any expert on autism spectrum disorders, in the school systems or [among] people that do these evaluations all the time, who doesn’t believe there’s a true increase,” Benaron said.

The second study looks at the genetic roots of autism. By tracking one of the approximately 1,000 gene mutations traced to ASD, scientists have gained additional insight into one physiological mechanism behind the condition.

Researchers from the University of North Carolina School of Medicine had a technical and specific summation, reflecting the limited scope. One media headline, “New Breakthrough in What Causes Autism,” is technically true, but also an overstatement based on past research Benaron has read in depth.

“All this is more information to fill in some of the gaps in the story,” she said. “Even though there were gaps in the story, they were mechanistic gaps; no one that was following this literature ever doubted that it would be figured out at some point. This is just adding more information to a framework.”

Benaron is not criticizing the validity or value of the genetic study, but rather believes that “the more information that gets added to the framework, the more you believe the framework.” She simply pointed out that autism’s mystery hasn’t been unlocked by understanding this single problem (a “missense mutation”) in the creation of a single gene (related to UBE3A, an enzyme that tags proteins for destruction).

Despite such disclaimers, each of the recent studies added to the public dialogue about autism—which, according to Dr. Eric Neal, may actually relate to the prevalence issue.

“Part of the rise in autism is the rise in awareness of it, better study and better understanding of it,” Neal said. He’s a pediatrician at Oroville Hospital who has been practicing since 1996. “I’m also seeing a lot more autism than I was in the past, too, but it’s so hard to quantify. I don’t think it’s that we went from 1 in 5,000 [the CDC statistic from 1975] to 1 in 68 … but that we have more tools to pick it up and more understanding and awareness of autism over the last 10 years or so.”

Benaron explained that prevalence data has been recorded three ways: educational classifications, medical diagnoses and CDC studies. The new study highlights the subjective nature of identifying autism, based on who makes the assessment, but Benaron says using special education data as a measure of diagnostic accuracy raises red flags.

“Almost all those kids [with ASD] have anxiety; almost all those kids, if they’re not intellectually disabled, will have learning disabilities in the sense that they often will have lower verbal-related skills,” she said.

But even taking the study at face value—accepting that 65 percent of the increase in autism diagnoses come from reclassification—that leaves 34 percent of the increase coming from autism increasing.

“OK, that’s still 10 times [greater in a decade],” Benaron said. “That’s still a public health emergency, even if you take their lowest estimate of kids with autism spectrum disorders.”

The research into genetic factors of autism presents hope for more specific approaches toward identification and care. The latter most excites Neal, as a physician on the front lines with a dearth of medical therapies.

“It’s great to screen and diagnose,” he said, “but I think the treatment end is the most important thing. … If there was something down the line where you could actually cure autism or at least treat autism better than the options we have now—we don’t have medications—I would think [that advance] would be the biggest help from research.”

Benaron said further research might help answer “is there a special intervention that might help this specific group of kids” because so many separate mutations cause autism disorders. “The other hope,” she continued, “is once we have genetic information to help us categorize, then maybe we’ll be able to get better information about prevalence.”