title: Brief Report: Characteristics of preschool children with ASD vary by ascertainment.
abstract: Prospective studies of infant siblings of children diagnosed with autism spectrum disorder (ASD) provide a unique opportunity to characterize ASD as it unfolds. A critical question that remains unanswered is whether and how these children with ASD resemble other children identified from the community, including those with no family history. The purpose of this study was to compare clinical characteristics of children with ASD identified by each method (n = 86 per group), drawn from two Canadian longitudinal research cohorts. Children ascertained from a prospective cohort were less severely affected and included a larger proportion of girls, compared to the clinically referred sample. These results may have important implications for conclusions drawn from studies of high-risk and clinically referred cohorts.
authors.affiliation: Department of Pediatrics, University of Alberta, Edmonton, AB, Canada. sacrey@ualberta.ca.|Autism Research Centre-E209, Glenrose Rehabilitation Hospital, 10230-111 Avenue, Edmonton, AB, T5G 0B7, Canada. sacrey@ualberta.ca.
authors.forename: Lori-Ann R
authors.initials: LR
authors.lastname: Sacrey
authors.affiliation: Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.|Autism Research Centre-E209, Glenrose Rehabilitation Hospital, 10230-111 Avenue, Edmonton, AB, T5G 0B7, Canada.
authors.forename: Lonnie
authors.initials: L
authors.lastname: Zwaigenbaum
authors.affiliation: University of Toronto, Toronto, ON, Canada.|The Hospital for Sick Children, Toronto, ON, Canada.|Centre for Addiction and Mental Health, Toronto, ON, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Szatmari
authors.affiliation: Dalhousie University/IWK Health Centre, Halifax, NS, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Bryson
authors.affiliation: McMaster Univeristy, Hamilton, ON, Canada.
authors.forename: Stelios
authors.initials: S
authors.lastname: Georgiades
authors.affiliation: University of Toronto, Toronto, ON, Canada.|Bloorview Research Institute, Toronto, ON, Canada.
authors.forename: Jessica
authors.initials: J
authors.lastname: Brian
authors.affiliation: Dalhousie University/IWK Health Centre, Halifax, NS, Canada.
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Smith
authors.affiliation: University of Ottawa, Ottawa, ON, Canada.
authors.forename: Tracy
authors.initials: T
authors.lastname: Vaillancourt
authors.affiliation: Mount Allison University, Sackville, NB, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Garon
authors.affiliation: University of Toronto, Toronto, ON, Canada.|McMaster Children's Hospital/Hamilton Health Sciences, Hamilton, ON, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Roncadin
authors.affiliation: McGill University, Montreal, QC, Canada.
authors.forename: Mayada
authors.initials: M
authors.lastname: Elsabbagh
mesh_terms: D000067877:Autism Spectrum Disorder / Q000523:psychology*; D002170:Canada; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D035781:Siblings / Q000523:psychology*
keywords: Autism spectrum disorder; Community referral; Comparison; High-risk siblings; Prospective