A spit test may someday be used to help diagnose children with autism. Children with the complex neuro-developmental disorder often have trouble communicating, and a saliva test - which detects the levels of various proteins - could offer an objective way to identify youngsters with autism.
Children with autism spectrum disorder have differences in protein levels, compared to those who do not have autism, and those differences may be detected in their saliva.
Researchers at Clarkson University and the State University of New York at Plattsburgh found that nine proteins were elevated in the saliva of the six autistic children who were studied, and three proteins were lower or even absent.
Alisa Woods of the SUNY Plattsburgh Center for Neurobehavioral Health helped lead the study. She says youngsters suspected of having the disorder - which is marked by interpersonal communication difficulties and repetitive behaviors - are currently diagnosed after being observed by psychologists.
"They rely on behavior, they are complicated, there might be some subjectivity to them. Even though they are very, very good, [a saliva test] could be simpler; it might be a simple screening method and a more objective one," says Woods.
An estimated one in every 68 children in the United States has autism spectrum disorder and experts say that number is growing. Similar prevalences are likely around the world.
Woods says one of the dozen proteins that is altered in autistic children is linked to gastrointestinal problems.
"Because gastrointestinal distress is so common in people with autism, maybe this could be a biomarker for people with that problem. People with autism sometimes have difficulties communicating their symptoms because it's a social communication disorder. So, this biomarker could be useful for seeing if people have this type of problem... and it might direct treatment," says Woods.
Another protein in the complex involves immune function.
Woods says researchers gravitated toward a saliva test because it is quick and easy to perform. It could identify the disorder earlier than waiting for behaviors to develop, so treatment could begin sooner.
She says the results of study - published in the journal Autism Research - need to be repeated by scientists, in larger groups of children, to determine whether a saliva test for autism could become a reality.