Siblings of autistic children may share some symptoms

Survey finds surprising number of girls affected but not diagnosed

Autism seems to play a genetically inspired hide-and-seek game in some families. Undiagnosed siblings in families that include two or more children with autism often grapple with language delays, social difficulties and other mild symptoms of the disorder, a new study suggests.

Genes prompt autism symptoms of varying intensity among members of these families, including in some kids who don’t qualify as having an autism spectrum disorder, say psychiatrist John Constantino of Washington University School of Medicine in St.