Much of the coverage of autism in the media focuses on the arguments of advocates, scientists, and government officials over the relationship between vaccines and autism. But out of the spotlight, a bigger story is brewing: the hunt for autism genes, a technically difficult hunt which is pressing forward using all of the tools modern genetics has to offer. If you are like me, news stories about autism have left you with only a vague impression of the current scientific state of understanding, the impression that researchers strongly deny any link between autism and vaccines, but have little else to say about what the real cause of autism might be.

If that is your impression, you'll perhaps be surprised to learn that roughly 20% of autism cases in the US are linked to known genetic changes, a minor fraction of autism cases to be sure, but much higher than I would have guessed. That autism has a genetic basis is a well-established finding, and while this by no means rules out environmental factors, genetics is at the core of the recent progress scientists have made in understanding autism. The genetics of autism, however, is not simple - no surprise, since autism involves our most complex organ, the brain, in one of its most complex functions, social interaction. Untangling the genetic and environmental factors that underlie autism will be tough, but in the process we will learn more about how many different genes work together in a child to control the developing brain.