U.S. autism rates reach new height: CDC
ENVIRONMENTAL FACTORS
Scientists had long estimated that 90 percent of autism risk was genes and 10 percent reflected environmental factors. But a 2011 study of twins by scientists at Stanford University concluded that genes account for 38 percent of autism risk and environmental factors 62 percent.
Exactly what those factors are, however, remains the subject of intense research, with two large studies funded by the National Institutes of Health examining everything from what the mother of a child with autism ate during her pregnancy to what cleaners were in the house and what pollutants were in the dust.
Autism Rate Now at One Percent of All US Children?
A pair of federally funded studies on autism rates is about to make news - big news - and it isn’t good: It would appear that somewhere around one percent of all US children currently have an autism spectrum disorder. The rate is even higher among six to 11 year olds and among boys, according to data from at least one of the new studies.
If you are an expectant parent, or planning to have a child soon, you might want to sit down before absorbing these staggering statistics, recently released by the National Survey of Children’s Health (NSCH), which is supported by the Health Resources and Services Administration (HRSA) of the US Department of Health and Human Services.
According to data from the 2007 telephone survey of parents of nearly 82,000 US children, the odds of a parent being told that their child has an ASD are one in 63. If it is a boy, the chances climb to a science fiction-like level of one in 38, or 2.6% of all male children in America.
But there was also some surprisingly good news. Enormous numbers of children who were told that they had autism went on to shed the ASD label as they got older, parents reported.
Among all children aged two to 17, according to respondents, one in 100 (100-per-10,000) currently have an ASD, which is considerably higher than the previously (CDC) estimated rate of 1-in-150, (or 66-per-10,000).
“There is not a clear frontrunner” among possible environmental causes of autism, said Craig Newshaffer, chair of the Department of Epidemiology and Biostatistics at Drexel University School of Public Health and lead investigator of one of the NIH-sponsored studies.
There is, however, what he called “good evidence” that any environmental culprit is present during the second or third trimester, the peak of synapse formation. Scientists believe that faulty brain wiring underlies autism.
They have also focused on factors that have changed in the last two decades, including pregnant women’s use of certain antidepressants, increasing parental age and the rise in pre-term births and low-birth weight babies, said Newshaffer.
Research funded by Autism Speaks found that autism costs the United States $126 billion annually. That reflects the cost of healthcare, special education and other services, as well as loss of productivity, underemployment and unemployment among adults with autism.
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By Sharon Begley