New research could help predict autism before 2 years old

The study looked at 106 infants considered to be at high risk for autism because they had an older sibling with the developmental disorder and 42 low-risk infants.

The surface area of the cortex grows significantly faster between the ages of 6 and 12 months in children with autism than in those without the condition, the researchers found. At that point, the overall brain volume increases faster in children with autism than in controls. "The earlier an intervention is implemented, the better the outcome for kids with autism". That brain volume "overgrowth" was linked to the emergence of social symptoms related to autism in the children's second year, which can include things like not engaging in pretend play and delayed speech and language. Signs of overgrowth were observed in 15 high-risk infants who were diagnosed with autism at 24 months.

They say they were able to predict which ones were going to develop autism with 80 percent accuracy. The brain differences at 6 and 12 months of age in infants with older siblings with autism correctly predicted eight out of ten infants who would later meet criteria for autism at 24 months of age in comparison to those infants with older ASD siblings who did not meet criteria for autism at 24 months.

As an NIH-funded Autism Center of Excellence, the researchers' data and tools are open-source and will eventually be submitted to the NIH's National Database for Autism Research.

Autism spectrum disorder affects an estimated one in 68 children in the U.S. Early detection is important, but children typically can't be diagnosed until after the age of two, when they start exhibiting symptoms such as repetitive behavior and difficulty interacting with others.

The study, published today in Nature, is the first to show it is possible to identify which infants - among those with older siblings with autism - will be diagnosed with autism at 24 months of age. These so-called 'baby sibs' are about 20 times more likely to have autism than are children in the general population.

The researchers made measurements of cortical surface areas and cortical thickness at 6 and 12 months of age and studied the rate of growth between 6 and 12 months of age.

This research project included hundreds of children from across the country and was led by researchers at the Carolina Institute for Developmental Disabilities (CIDD) at the University of North Carolina, where Piven is director.

This rapid growth can in fact predict whether a child will later be diagnosed with autism. "We're learning that there are biological changes that occur at [the time] or before the symptoms start to emerge", says Geraldine Dawson, a clinical psychologist and autism researcher at Duke University who was not involved in the new work.

If these findings could form the basis for a "pre-symptomatic" diagnosis of ASD, health care professionals could intervene even earlier.

"This means we potentially can identify infants who will later develop autism, before the symptoms of autism begin to consolidate into a diagnosis", Piven said.

But in the future, it's possible to envision families with high-risk infants using such a scan to plan for treatment if needed, said Paul Thompson, a neuroimaging specialist at the University of Southern California's Keck School of Medicine of USC. "In Parkinson's, for instance, we know that once a person is diagnosed, they've already lost a substantial portion of the dopamine receptors in their brain, making treatment less effective".

"So we find it very promising". Parents who already have a child with autism may find it particularly hard to show up for repeated brain scans, Piven says.

  • Joe Gonzales