Parental Reports of ASD Proband Functioning Are Associated with Outcomes at 24 Months in Infant Siblings

Oral Presentation
Friday, May 3, 2019: 2:06 PM
Room: 517C (Palais des congres de Montreal)
J. B. Girault1, M. R. Swanson2, R. L. Grzadzinski3, M. D. Shen1, S. S. Meera4, J. Pandey5, T. St. John6, A. Estes6, L. Zwaigenbaum7, K. Botteron8, H. C. Hazlett1, S. R. Dager6, R. T. Schultz5, J. N. Constantino8 and J. Piven9, (1)University of North Carolina, Chapel Hill, NC, (2)University of North Carolina at Chapel Hill, Chapel Hill, NC, (3)University of North Carolina Chapel Hill, Chapel Hill, NC, (4)Carolina Institute of Developmental Disabilities, University of North Carolina at Chapel Hill, Carrboro, NC, (5)Center for Autism Research, Children's Hospital of Philadelphia, Philadelphia, PA, (6)University of Washington, Seattle, WA, (7)University of Alberta, Edmonton, AB, Canada, (8)Washington University School of Medicine, St. Louis, MO, (9)*Co-Senior Authors, IBIS Network, University of North Carolina, Chapel Hill, NC
Background: ASD is heritable and infant siblings of children with ASD are at greater risk for receiving a diagnosis, though it remains unclear whether functioning of the proband is related to dimensional outcomes of the infant siblings.

Objectives: To determine if dimensional parent report measures of developmental functioning and autism symptom severity in probands are related to infant sibling outcomes at 24 months.


Participants: Participants were recruited as part of the Infant Brain Imaging Study (IBIS), a longitudinal, multi-site study of brain and behavioral development in children at high-familial risk (HR) for ASD. Data from 406 proband and HR infant sibling pairs were included, in which 92 HR infant siblings were diagnosed with ASD at 24 months (HR-ASD) and 314 were negative for ASD (HR-Neg).

Measures:Parental reports of proband ASD severity were evaluated using the Autism Diagnostic Interview – Revised (ADI-R) and the Social Communication Questionnaire (SCQ), and reports of dimensional adaptive behaviors were collected with the Vineland Adaptive Behavior Scales (VABS). Infant measures of interest included examiner-based language and motor performance on the Mullen Scales of Early Learning (MSEL), Autism Diagnostic Observation Schedule (ADOS) scores, and parental reports from the VABS at 24 months.

Analysis:(1) To determine if proband functioning and severity differed between HR-ASD and HR-Neg groups, an ANCOVA testing for main effects of sibling diagnostic group were employed, adjusting for proband and sibling sex and age at measurement. (2) Robust linear regression was used to predict sibling outcomes at 24 months from proband parental reports adjusting for diagnostic group of the sibling, proband and sibling sex and age at measurement, and interacting effects of proband scores and sibling diagnostic group.

Results: Probands of HR-ASD infants were significantly more impaired than those of HR-Neg infants on the SCQ (F1,356=5.98, p=0.016, Cohen’s d=0.30)and measures of daily living skills (F1,338=7.21, p=0.008,d=-0.31), socialization (F1,337=5.17, p=0.024d=-0.23), and communication (F1,337=5.26, p=0.023, d=-0.26) on the VABS (Figure 1). Across the HR sample, there were significant associations between proband SCQ scores and sibling Adaptive Behavior Composite (ABC) scores from the VABS (b=-0.27, p=0.032), between proband and sibling VABS ABC scores (b=0.34, p=0.004), socialization scale scores (b=0.34, p=0.023), and communication scale scores (b=0.47, p<0.0001). Proband parental reports of language from the VABS were significantly associated with examiner-based assessments of infant sibling MSEL expressive (b=0.32, p<0.01) and receptive language (b=0.76, p<0.001), as well as parental reports of these measures from the VABS (expressive: b=0.39, p<0.001, receptive:b=0.52, p<0.0001; Figure 2). Significant interactions for infant diagnostic group and proband score were found when predicting infant communication (b=-0.36, p<0.01) and receptive language (from VABS: b= -0.29, p=0.021, from MSEL: = -0.74, p<0.001;Figure 2B,C). No significant associations were found between proband ADI-R and infant sibling outcomes, proband measures and infant ADOS scores, or proband and infant motor skills.

Conclusions: This study demonstrates that parent reports of proband functioning are associated with categorical diagnostic outcomes and both parent reports and examiner-based clinical assessments of dimensional outcomes in infant siblings.

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See more of: Early Development (< 48 months)