Early language profiles in infants at high-risk for autism spectrum disorders.

Many preschoolers with autism spectrum disorders (ASD) present relative lack of receptive advantage over concurrent expressive language. Such profile emergence was investigated longitudinally in 54 infants at high-risk (HR) for ASD and 50 low-risk controls, with three language measures taken across four visits (around 7, 14, 24, 38 months). HR infants presented three outcome subgroups: ASD, other atypicality, and typical development. Reduced receptive vocabulary advantage was observed in HR infants by 14 months, but was maintained to 24 months only in ASD/other atypicality outcome subgroups while typically-developing HR infants regained a more normative profile. Few group differences appeared on a direct assessment of language and parent-reported functional communication. Processes of early development toward ASD outcome and in intermediate phenotypes are discussed.