A Unique Cognitive Profile of ASD Evident in Siblings, Parents, and Grandparents of Individuals with ASD

Poster Presentation
Friday, May 11, 2018: 5:30 PM-7:00 PM
Hall Grote Zaal (de Doelen ICC Rotterdam)
M. Losh1, L. Bush2, K. Nayar3, M. Lee4, G. E. Martin5, M. Winston3, S. Crawford6, J. Sideris7, D. Achorn8, S. Lapham8, C. Persico9, J. Ferrie10 and D. Figlio4, (1)Communication Sciences and Disorders, Northwestern University, Evanston, IL, (2)Northwestern Feinberg School of Medicine, Chicago, IL, (3)Feinberg School of Medicine, Department of Psychiatry and Behavioral Sciences, Northwestern University, Evanston, IL, (4)Northwestern University, Evanston, IL, (5)Communication Sciences and Disorders, St. John's University, Staten Island, NY, (6)Communication Sciences and Disorders, Northwestern University, Chicago, IL, (7)Frank Porter Graham Child Development Institute, Chapel Hill, NC, (8)American Institutes for Research, Washington, DC, (9)University of Wisconsin-Madison, Madison, WI, (10)Economics, Northwestern University, Evanston, IL
Background: Genetic liability to autism spectrum disorder (ASD) can be expressed in unaffected relatives through subclinical, genetically meaningful traits, or endophenotypes. Studying endophenotypes in unaffected relatives may help to decompose the complex ASD phenotype into more fundamental component features with clearer ties to underlying biology, which can be used to stratify families into biologically meaningful subgroups. This study makes use of three unique datasets of archival educational data available on siblings, parents, grandparents, and great-grandparents of individuals with ASD, to investigate cognitive profiles that may be related to ASD genetic liability.

Objectives: To explore the role of educational test data across multiple generations of individuals with autism and their family members, this study used archival test records from 1) a large population-based sample of children for whom later autism diagnostic information was available, 2) parents of individuals with and without autism, and 3) grandparents and great-grandparents of individuals with autism.

Methods: Three datasets comprising different archival academic test records were examined. First, individuals with ASD and their siblings were identified from a population-based sample of children attending kindergarten in Florida (n=292,407) who as preschoolers were administered a kindergarten readiness screener, the Dynamic Indicators of Basic Early Literacy Skills Kindergarten Readiness Test (DIBELS), which assesses letter and sound recognition. Academic testing for reading and math was also available at 3rd grade from children with and without ASD (n=1,281,005) from this sample. Childhood educational data from parents of individuals with ASD (n=144) and 75 controls were examined from the Iowa Tests of Basic Skills (ITBS), which assesses math, reading, and language from grades K-12. Childhood educational data from grandparents (n=19) and great-grandparents (n=2) of individuals with ASD was examined with data from Project Talent, a nation-wide study that assessed academic competencies, family background, and personal and educational experiences of high school students in 1960.

Results: Across all three samples and academic tests, a pattern of discordant skills was observed. In preschool age screening data, a discordant pattern of strong letter recognition and weaker sound recognition scores was strongly predictive of ASD (OR=2.74; p<.0001) and ASD-sibling status (OR=1.42; p<.0001). Later in development, greater discordance between reading and math scores was strongly predictive of ASD status (OR=2.03; p<.0001; sibling data will be processed and analyzed). In parents, results again revealed discordance between reading and math scores among ASD parents, where reading scores exceeded math scores. Multinomial regression predicted ASD-parent status with 74% accuracy and specificity of 95%. In grandparents and a small sample of two great-grandparents, 85% of the sample showed better reading vocabulary scores than math (with nearly 3/4 of the sample scoring below the 50th percentile on math). Greater discordance between reading vocabulary and math was associated with ASD endophenotypes in adulthood, with a small to medium effect size (r=.27; p=.31).

Conclusions: These findings suggest a unique cognitive profile of discordant cognitive skills evident in siblings, parents, and grandparents of individuals with ASD. This profile predicts endophenotypes in adulthood, and may be used to help inform understanding of the pathogenesis of ASD.

See more of: Genetics
See more of: Genetics