An increased growth in brain volume was found to be a likely indication that autism would develop and the team's algorithm was able to predict which of the children would develop autism with an accuracy rate of 81 per cent, suggesting autism could be detected before the diagnosis age of two. By analyzing brain scans of more than 150 infants - two thirds of whom had a brother or sister with autism, putting them at a much higher risk of developing the condition- the researchers pinpointed autism biomarkers. "The fact that they're not consistent suggests that some of the expansion in surface area may actually not be relevant to the detection of autism", he says. Researchers believe that the brain changes underlying ASD begin much earlier - possibly even in the womb. At the same time, the technique employed nearly flawlessly predicted which babies at high risk of developing the disease would not suffer from autism. And because it was tested only on high-risk infants, it's also unclear whether the procedure would help predict autism in typical, healthy families.
The study's most important immediate contribution lies in providing more evidence for the overgrowth theory, along with identifying additional brain regions that may be affected, said one of the non-involved researchers, Eric Courchesne, an autism expert at UC San Diego. But behavioural assessments haven't been helpful in predicting who will get autism, says Joseph Piven, a psychiatrist at the University of North Carolina (UNC) in Chapel Hill, who co-led the study, published online in Nature.
Boys are almost five times more likely than girls to have autism.
About 1 in 68 US children has been diagnosed on the autism spectrum, according to the latest report from the CDC. That's pretty damn good compared with behavioral questionnaires, which yield information that leads to early autism diagnoses (at around 12 months old) that are just 50 percent accurate. However, researchers call for more work, as there is no telling yet of the social impact of this technique, especially as to how family members would react to such an early diagnosis. There are about 3 million people with autism in the United States and tens of millions around the world.
Botteron says they still need to duplicate these findings in a larger study.
Identifying those physical differences correctly predicted 80 percent of the children in the second high-risk group who met the clinical criteria for autism. Other key collaborators were New York University, the College of Charleston, McGill University and the University of Alberta. That change happened before the child's first birthday. Once children have missed those developmental milestones, she added, catching up is a struggle for many and almost impossible for some.
With funding from the National Institutes of Health, the University of Minnesota team found that they now have an opportunity to understand how early autism unfolds in life.