Sex Differences in Children with Autism Spectrum Disorder Identified Within a High-Risk Infant Cohort

Sex differences were examined in 3-year-olds with autism spectrum disorders (ASD) ascertained from a high-risk cohort, and high- and low-risk comparison groups. Participants included 319 high-risk siblings and 129 low-risk controls. Eighty-five siblings were diagnosed with ASD, including 57 of 176 boys (32.4 %) and 28 of 143 girls (19.6 %), implying a relative odds of ASD of 1.65 in boys versus girls. There were modest sex differences on...