Atypical development in siblings of autism sufferers detectable at 12 months

Researchers have suggested that atypical development can be detected as early as 12 months of age among the siblings of autism sufferers.

The study found that close to half of the younger siblings of children with autism spectrum disorder (ASD) develop in an atypical fashion, with 17 percent developing ASD and another 28 percent showing delays in other areas of development or behavior.

Among the 28 percent of children with older siblings with ASD who showed delays in other areas of development, differences were identified in their social, communication, cognitive or motor development by 12 months.

The most common deficits were in the social-communication domain, such as extreme shyness with unfamiliar people, lower levels of eye contact and delayed pointing.

The research suggests that parents and clinicians should be vigilant for such symptoms early on among the siblings of children with autism, in order to take full advantage of opportunities for targeted early intervention to improve those children's outcomes.

The study was conducted in 294 infant siblings of children with autism spectrum disorder and 116 infant siblings of children with typical development. All of the study participants were enrolled prior to 18 months of age. Data on the children's development was collected at 6, 12, 18, 24 and 36 months of age using a variety of standard developmental tests for autism symptoms.

The study has been published online in the Journal of the American Academy of Child and Adolescent Psychiatry.