Siblings with autism tend to behave as differently as any other siblings, according to a new study that highlights what the New York Times calls the "exasperating diversity of autism, even in the most closely related individuals." The researchers analyzed genetic material from 85 families that had two autistic children and found that 70% of the sibling pairs had different genetic glitches, with the children exhibiting very different symptoms and behavior patterns. Experts say the study exposes the limits of genetic mapping of autism—and the difficulty of predicting whether a family with one autistic child will have another.
There are so many genetic differences in autism cases that "autisms" is a better term, the lead researcher, from Toronto's Hospital for Sick Children, tells Reuters. "There are many different forms of autism," he says. "In other words, autism is more of a collection of different disorders that have a common clinical manifestation." He says the study shows that children, even siblings, diagnosed as autistic "need to be treated in their own special way." Genetic research is helping the development of new drugs, he says, but for now, "the best treatment for the core features in the autisms is actually intensive behavioral intervention. For this, for the best outcomes, you need to start early." (Read more autism stories.)