As countless parents now have learned, as soon as you set out to learn about autism, you run into frustrating unknowns.
Why are more and more children being diagnosed with it now about 1 in every 150 children born? Why are its symptoms more severe in some children than in others? Why are so many more boys diagnosed than girls -- four boys for every one girl? What if any environmental toxins trigger the disease in the brains of developing fetuses?
Above all: how can it be prevented?
Scientists are hard at work on the answers to these questions, but the questions remain as a central part of the disease, and coupled with the increase in diagnoses in the past two decades they are what make the disease so widely discussed, and so controversial.
Autism is characterized by its symptoms, and because the severity of those symptoms vary, the disease is thought of as a "spectrum disorder" one that affects one child more severely than others.
Symptoms emerge very early in life and last throughout. Children are unable to interact with people as others do: for instance, they may shun hugs, fail to understand facial cues that are an intuitive form of communication to others, maintain unusual focus on seemingly inconsequential things, and develop repetitive physical tics like rocking back and forth.
Because chemicals have been shown to interrupt or disrupt the normal development of the brain during fetal development in the womb and during early childhood development, environmental toxins have long been suspects in the search for a cause. In a variety of diseases, chemicals and other environmental cues are thought of as triggers that prompt genes to act, and a genetic pre-disposition to autism is also thought to be part of the equation.
But the final chapters have yet to be written about autism. Research constantly sheds new light and, as good science does, raises new questions about a beguiling disease.
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