What Causes Autism? Genetics and Pollution are “About Equal”

“….genetic factors and brain changes triggered by man-made chemicals in the
environment are equally to blame for the development of autism in young
children,” according to panelists at a recent American Association for the Advancement of Science panel in Vancover as reported in the Irish Times last Monday. Professor Scott Selleck of Penn State is quoted as saying “A number of genetic alterations have emerged as important in autistic
disorders but persistent chemicals in the environment including flame
retardants and polychlorinated biphenyls (PCBs) were also important. The balance of genetic and environmental contributors is about equal.
It is 50/50.”  Dr. Janine LaSalle of the University of California, Davis talked about her research on “how exposure to persistent chemicals such as flame retardants could
cause long-lived changes in how collections of genes were expressed, for
example the genes associated with building neurological networks.” She referred to this phenomena as “epigenetics”. That’s when the genes themselves are not mutated but they way the genes express themselves is changed. And it can be caused or made worse “by low-level environmental chemicals.” LaSalle
“exposed mouse models to the flame retardant PBE-47 and polychlorinated
biphenyl MECP-2 at minute levels that matched human exposures. It affected both sociability of these mice and also their learning behavior.” The article ends by noting that “There were now upwards of 80,000 non-natural chemicals in the
environment produced by industrial processes and other sources. Few had been tested for their neurotoxicity despite human
exposures to these substances.”  Autism now affects more American children than
childhood cancer, diabetes and AIDS combined. In the last decade, the
number of children diagnosed with autism spectrum has grown significantly.
The Centers for Disease Control now puts the rate at one in 110.