A new study found that exposure to air pollution increases a person’s risk for developing autism if they have a genetic disposition for the neurological disorder.
The study’s lead authors say that the research showed children with both the risk genotype and exposure to high air pollutant levels were at increased risk of developing an autism spectrum disorder compared to those without the risk genotype and lower air pollution exposure.
The full study, “Autism Spectrum Disorder: Interaction of Air Pollution with the MET Receptor Tyrosine Kinase Gene,” from the University of Southern California, is scheduled to appear in the January 2014 edition of Epidemiology.
According to recent statistics, about one in every 88 children has an autism spectrum disorder, meaning they are unable to comprehend social situations, struggle to communicate and have repetitive behaviors.
Although various studies in recent years have suggested that genetics play an important role in whether a person will develop the disorder, this is one of the first studies that illustrates the role of environmental factors as well.
“Although gene-environment interactions are widely believed to contribute to autism risk, this is the first demonstration of a specific interaction between a well-established genetic risk factor and an environmental factor that independently contribute to autism risk,” said Daniel B. Campbell, Ph.D., an assistant professor of psychiatry and the behavioral sciences at the Keck School of Medicine at USC and the study’s senior author.
“The MET gene variant has been associated with autism in multiple studies, controls expression of MET protein in both the brain and the immune system, and predicts altered brain structure and function. It will be important to replicate this finding and to determine the mechanisms by which these genetic and environmental factors interact to increase the risk for autism”
For the study, researchers examined 408 children between the ages of 2 and 5 from the Childhood Autism Risks for Genetics and the Environment Study, which is a population-based, case-control group of preschool children living in California.
From the sample, the study found that of the 408 children, 252 met the criteria for having an autism spectrum disorder based on hereditary indicators found via a blood test. Of those children, many of them and their mothers reportedly lived in environments with high levels of air pollution that the researchers believed increased the children’s risk for developing the disease.
Based on the results, researchers say they will continue to study how air pollution exposure affects the MET genotype in mothers during pregnancy, to determine how genetic variants and air pollution affect a person’s risk of developing autism.
As of now, there is no known cure for autism, which is why scientists continue to research its causes and why it develops. According to an Autism news site, much of the research surrounding the disease indicates that the condition is highly heritable, so in order to develop a cure, scientists believe there needs to be more research examining how inherited genetics relate to the onset of an autism spectrum disorder.