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Multicenter Study
. 2014 Dec;53(12):1317-1327.e1.
doi: 10.1016/j.jaac.2014.09.015. Epub 2014 Oct 2.

18-month predictors of later outcomes in younger siblings of children with autism spectrum disorder: a baby siblings research consortium study

Katarzyna Chawarska  1 , Frederick Shic  2 , Suzanne Macari  2 , Daniel J Campbell  3 , Jessica Brian  4 , Rebecca Landa  5 , Ted Hutman  6 , Charles A Nelson  7 , Sally Ozonoff  8 , Helen Tager-Flusberg  9 , Gregory S Young  8 , Lonnie Zwaigenbaum  10 , Ira L Cohen  11 , Tony Charman  12 , Daniel S Messinger  13 , Ami Klin  14 , Scott Johnson  6 , Susan Bryson  15
Affiliations
Multicenter Study

18-month predictors of later outcomes in younger siblings of children with autism spectrum disorder: a baby siblings research consortium study

Katarzyna Chawarska et al. J Am Acad Child Adolesc Psychiatry. 2014 Dec.

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.

Keywords: ASD; broader autism phenotype; high-risk siblings; infants; predictors of outcomes.

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Conflict of interest statement

Disclosure: Drs. Chawarska, Macari, Brian, Landa, Hutman, Nelson, Ozonoff, Tager-Flusberg, Young, Cohen, Messinger, Klin, Johnson, and Bryson report no biomedical financial interests or potential conflicts of interest.

Figures

Figure 1
Figure 1
Classification and Regression Tree (CART) diagram predicting groups with autism spectrum disorder (ASD), atypical development (ATYP), and typical development (TD) based on 18-month Autism Diagnostic Observation Schedule (ADOS) item data. Note: The bars reflect the proportion of toddlers from each diagnostic group assigned into each leaf based on their presentation during ADOS evaluation. ADOS items used in the tree are B1 (Unusual Eye Contact), D4 (Unusually Repetitive Interests or Stereotyped Behaviors [RSB]), A3 (Intonation of Vocalizations or Verbalizations), B8 (Giving), C2 (Imagination/Creativity), and A8 (Gestures). The numbers displayed to the left and to the right of the item label reflect the actual scores on the given item of the ADOS.
Figure 2
Figure 2
Marginal means (+/− 2 standard errors) of severity scores, verbal developmental quotient (DQ) scores, and nonverbal DQ scores in children with autism spectrum disorder (ASD) classified correctly as ASD and misclassified as typically or atypically developing at 18 months.
See this image and copyright information in PMC

References

    1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM 5. 5th ed. Washington, DC: Author; 2013.
    1. Baio J. Prevalence of Autism Spectrum Disorders: Autism and Developmental Disabilities Monitoring Network, 14 Sites, United States, 2008. Morbidity and Mortality Weekly Report. Surveillance Summaries (Centers for Disease Control and Prevention) 2012;61:1–19. - PubMed
    1. Geschwind DH. Genetics of autism spectrum disorders. Trends in Cognitive Sciences. 2011;15(9):409–416. - PMC - PubMed
    1. Ozonoff S, Young GS, Carter A, et al. Recurrence Risk for Autism Spectrum Disorders: A Baby Siblings Research Consortium Study. Pediatrics. 2011;128:e488–e495. - PMC - PubMed
    1. Georgiades S, Szatmari P, Zwaigenbaum L, et al. A Prospective Study of Autistic-Like Traits in Unaffected Siblings of Probands With Autism Spectrum Disorder Autistic Traits in Siblings of Probands With ASD. JAMA psychiatry. 2013;70(1):42–48. - PubMed

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