18-Month Predictors of Later Outcomes in Younger Siblings of Children With Autism Spectrum Disorder: A Baby Siblings Research Consortium Study

• Type of Material: Article
• Authors: Katarzyna Chawarska, Yale University; Frederick Shic, Yale University; Suzanne Macari, Yale University; Daniel J. Campbell, Amgen Inc.; Jessica Brian, University of Toronto; Rebecca Landa, Johns Hopkins School of Medicine; Ted Hutman, University of California Los Angeles; Charles A. Nelson, Harvard University; Sally Ozonoff, University of California Davis; Helen Tager-Flusberg, Boston University; Gregory S. Young, University of California Davis; Lonnie Zwaigenbaum, University of Alberta; Ira L. Cohen, New York State Institute for Basic Research in Developmental Disabilities; Tony Charman, Kings College London; Daniel S. Messinger, University of Miami; Ami Klin, Emory University; Scott Johnson, University of California Los Angeles; Susan Bryson, Dalhousie University
• Language: English
• Date: 2014-12-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2014 American Academy of Child and Adolescent Psychiatry.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jaac.2014.09.015
• Title of Journal or Parent Work: Journal of the American Academy of Child and Adolescent Psychiatry
• ISSN: 0890-8567
• Volume: 53
• Issue: 12
• Start Page: 1317
• End Page: 1327
• Grant/Funding Information: Autism Speaks (AS) provided funding for the creation of the Baby Siblings Research Consortium (BSRC) database.; Data collection, analyses, and manuscript preparation were supported by the National Institutes of Health (NIH) grants P01 HD003008; Project 1 (K.C.); R01MH087554 (Principal Investigator [PI]: K.C.); CTSA UL1 RR024139 (F.S.); MH096961 (T.H.); MH068172 (T.H.); HD055784 (T.H. and S.J.); MH068398 (PI: S.O.); R01DC010290 (Multiple Principal Investigators [MPI]: H.T.F. and C.A.N.); R21DC008637 (PI: H.T.F.); R01GM105004 (D.S.M.); R01HD057284 and R01GM105004 (D.S.M.); P50MH100029 (A.K.); R01MH083727 (A.K.); and R01MH059630 (R.L.); UK Medical Research Council (T.C.); European Science Foundation Cooperation in Science and Technology (COST) Action BM1004 (ESSEA) under FP7 (T.C.); Canadian Institutes of Health Research (CIHR) (J.B., S.B., L.Z.); NeuroDevNet (J.B., S.B., L.Z.); Simons Foundation (PI: C.A.N.); and AS Pilot Grant (PI: H.T.F); AS Postdoctoral Fellowship (D.J.C.); and AS Canada (J.B., S.B., L.Z.).
• Keywords: broader autism phenotype; Life Sciences & Biomedicine; high-risk siblings; Pediatrics; Psychiatry; Psychology, Developmental; DIAGNOSIS; Science & Technology; predictors of outcomes; ASD; Social Sciences; infants; Psychology; RISK
• Research Categories: Psychology, Developmental; Health Sciences, Mental Health

Abstract

Objective: Younger siblings of children with autism spectrum disorder (ASD) are at high risk (HR) for developing ASD as well as features of the broader autism phenotype. Although this complicates early diagnostic considerations in this cohort, it also provides an opportunity to examine patterns of behavior associated specifically with ASD compared to other developmental outcomes. Method: We applied Classification and Regression Trees (CART) analysis to individual items of the Autism Diagnostic Observation Schedule (ADOS) in 719 HR siblings to identify behavioral features at 18 months that were predictive of diagnostic outcomes (ASD, atypical development, and typical development) at 36 months. Results: Three distinct combinations of features at 18 months were predictive of ASD outcome: poor eye contact combined with lack of communicative gestures and giving; poor eye contact combined with a lack of imaginative play; and lack of giving and presence of repetitive behaviors, but with intact eye contact. These 18-month behavioral profiles predicted ASD versus non-ASD status at 36 months with 82.7% accuracy in an initial test sample and 77.3% accuracy in a validation sample. Clinical features at age 3 years among children with ASD varied as a function of their 18-month symptom profiles. Children with ASD who were misclassified at 18 months were higher functioning, and their autism symptoms increased between 18 and 36 months. Conclusion: These findings suggest the presence of different developmental pathways to ASD in HR siblings. Understanding such pathways will provide clearer targets for neural and genetic research and identification of developmentally specific treatments for ASD.