Report Cites Behavioral and Genetic Differences Among Siblings with Autism

Most siblings with a diagnosis of autism do not share the same genetic risk factors for the disorder and are as distinct in their behaviors as any brothers and sisters, scientists reported on Monday in a study that came as a surprise to many doctors, if not to parents.

Scientists analyzed genetic material from 85 families, using a technology called whole-genome sequencing. Unlike other approaches, which illuminate a sample of a person’s genetic material, the whole-genome technique maps out the entire voluminous recipe, every biological typo, every misplaced comma or transposed letter. Each of the families had two children with a diagnosis of autism.