There is a mystery of autism that has been published this week. The fact is that parents of a child with autism face a risk of almost one in five that their next child will also develop the disorder. What does this mean? The largest study of siblings of children with autism attempts to explain.
The risk is higher than previous estimates, and goes even higher if the second child is a boy. In fact, the risk rises to over 26% if the second child is male, because the truth is that the disorder is mostly found among boys and over 32% for infants with more than one older sibling with autism.
Scientists are working hard to narrow down the regions on chromosomes 7 and 15 to identify the specific gene(s) related to autism on these chromosomes. They are also expanding their searches to investigate other chromosomes for which there is preliminary suggestive evidence.