Scientists at the Keck School of Medicine of the University of Southern California (USC) recently released newly published research that show exposure to air pollution increases the risk for autism among individuals who carry a genetic disposition for the neuro-developmental disorder.
The study’s first author, Heather E. Volk, Ph.D., M.P.H., assistant professor of research in preventive medicine and pediatrics at the Keck School of Medicine of USC and principal investigator at The Saban Research Institute of Children’s Hospital Los Angeles said “Our research shows that children with both the risk genotype and exposure to high air pollutant levels were at increased risk of autism spectrum disorder compared to those without the risk genotype and lower air pollution exposure,”
ASD, characterized by problems with communication, social interaction and repetitive behavior, is a lifelong neuro-developmental disability. With many questions about its cause, The Centers for Disease Control and Prevention estimates that one in 88 children in the United States has an ASD. No cure is currently available for the disorder, but it is suggested genetics play an important contributing factor.
“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., assistant professor of psychiatry and the behavioral sciences at the Keck School of Medicine of 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.”
The research team studied 408 children between two and five years of age from the Childhood Autism Risks From Genetics and the Environment Study, a population-based, case-control study of preschool children from California. Of the 408 children studied, 252 met the criteria for autism or autism spectrum disorder. The MET genotype was determined through blood sampling. Air pollution exposure was determined based on local traffic-related sources, regional air quality measures, and on the past residences of the children and their mothers.
Volk and Campbell have previously reported in independent studies the associations between autism and air pollution exposure and between autism and a variant in the MET gene. Their recent study suggests that the genetic variant and air pollution exposure work together to increase the risk of ASD. They continue to study the interaction of air pollution exposure and the MET genotype in mothers during pregnancy.
The study, “Autism spectrum disorder: Interaction of air pollution with the MET receptor tyrosine kinase gene,” is scheduled to appear in the January 2014 edition of Epidemiology.
For more information on autism research, read here: http://www.icare4autism.org/
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