What does the science suggest are the causes of autism?
There are probably several different kinds of autism caused by several different genetic pathways. There may be, in total, several dozen different genes involved. Scientists at Cold Springs Harbor Laboratory in New York have generated one of the most interesting genetic models, suggesting that some cases are heritable, but usually over the span of a couple of generations through a nonaffected carrier, and other cases are de novo mutations. But the bottom line is: it is largely genetic, so much so that environment probably plays [only] a small role. One way scientists estimate the role of genetics in a certain disorder is to look at concordance of that disorder in identical twins, that is, two people with identical DNA. The concordance, or percentage of people with identical DNA who both suffer from an autism spectrum disorder, is as high as 90 percent in some studies. That’s higher than the concordance for coronary artery disease, depression, or breast cancer. Then, when the scientists
