The sniff response in autistic children differs greatly from their peers, according to a new study. Autistic children do not automatically adjust their level of sniffing in response to different smells. In addition, researchers found a correlation between the level of atypical sniff response and the severity of children’s autism symptoms.
“The difference in sniffing pattern between the typically developing children and children with autism was simply overwhelming,” says study author Noam Sobel of the Weizmann Institute of Science in Israel.
Sniff response refers to how big a sniff people take of different smells. For example when smelling something pleasant such as a flower, most people take a deep breath. However, when smelling something offensive like sour milk, people limit their breath intake or amount of smell. This sniff response is automatic in most people.
The study involved 36 children, half of whom had autism spectrum disorder. Researchers exposed the children to a series of pleasant and unpleasant odours. A Pediatric olfactometer delivered the odours and measured the children’s sniff response.
In 81-percent of the cases, researchers identified the children with autism based on their different sniff response. Researchers also noted that the greater the difference of sniff response in the children with autism corresponded with the severity of the children’s autism symptoms.
“We can identify autism and its severity with meaningful accuracy within less than 10 minutes using a test that is completely non-verbal and entails no task to follow,” Sobel says. “This raises the hope that these findings could form the base for development of a diagnostic tool that can be applied very early on, such as in toddlers only a few months old. Such early diagnosis would allow for more effective intervention.”
“A Mechanistic Link between Olfaction and Autism Spectrum Disorder” is published in Cell Biology.