Lonnie Zwaigenbaum

Centre for Studies of Children at Risk


Prelude to autism: Insights from the early development of high risk infants.


To better inform early identification efforts, we have initiated a prospective study of high-risk infants, defined by virtue of having an older sibling with autism. Our goals are to identify developmental trajectories in this high-risk group, and to assess whether behavioural markers in the first year of life are predictive of later impairments. Our measures include a novel observational scale derived from retrospective reports, home videotape studies and our previous work investigating visual attention in autism. Operational definitions of target behaviours have been systematically refined, and the test-retest and inter-observer reliability at 12 months are excellent. The objectives for this rounds include:

1. To present our initial findings from this longitudinal study, which indicate that behavioural risk markers measured as early as 12 months of age are predictive of later social-communication impairments consistent with autism.

2. To discuss the range of developmental impairments observed in siblings, with reference to the concept of a 'broader autism phenotype' and the implications for genetic studies in autism.