30051
Links between Autism and the FMR1 Premutation: Insights from Studies of Gaze, Language, and Cognition in Carriers of the FMR1 Premutation

Poster Presentation
Thursday, May 2, 2019: 5:30 PM-7:00 PM
Room: 710 (Palais des congres de Montreal)
K. Nayar1, M. Winston1, A. L. Hogan2, W. S. McKinney3,4,5, G. E. Martin6, J. N. Barstein1, C. G. La Valle7 and M. Losh4, (1)Feinberg School of Medicine, Department of Psychiatry and Behavioral Sciences, Northwestern University, Evanston, IL, (2)Department of Psychology, University of South Carolina, Columbia, SC, (3)Kansas Center for Autism Research and Training (K-CART), University of Kansas, Lawrence, KS, (4)Communication Sciences and Disorders, Northwestern University, Evanston, IL, (5)Clinical Child Psychology Program, Schiefelbusch Institute for Life Span Studies, University of Kansas, Lawrence, KS, (6)Communication Sciences and Disorders, St. John's University, Staten Island, NY, (7)Department of Psychological and Brain Sciences, Boston University, Boston, MA
Background: Fragile X syndrome (FXS) is an X-linked, monogenic disorder resulting from a mutation of >200 CGG repeats in the fragile X mental retardation gene (FMR1), and is the most common monogenic disorder associated with autism spectrum disorder (ASD). Importantly, individuals with the FMR1 premutation (PM; 55-200 CGG repeats) have been reported to exhibit features of the broad autism phenotype (BAP), suggesting that the FMR1 gene may contribute to ASD-related features. This presentation will report findings from two eye-tracking tasks (that previously documented differences in ASD and the BAP), to investigate underlying cognitive processes related to language and social-emotional processing in PM carriers.

Objectives: To examine links between gaze, language, and social cognition in the FMR1 PM, to determine whether phenotypic similarities exist with ASD and the BAP.

Methods: Forty-eight PM carriers and 56 controls completed two eye-tracking tasks previously used in studies examining ASD and the BAP: 1) A language fluency task (i.e., rapid automatized naming, or RAN), which involved serially naming common symbols and non-symbols. Refixations (the repeated fixations to previously-fixated items) and eye-voice span (i.e., the coordination between gaze and speech; longer EVS indicating greater automaticity) were variables of interest. 2) A passive viewing emotion processing task using faces from the NimStim Face Stimulus Set, during which gaze to the mouth, eyes, and nose were explored. Social cognitive and language abilities were assessed using the Reading the Mind in the Eyes Test and the Pragmatic Rating Scale, respectively. Correlations between gaze, language, and social-cognitive abilities were examined, and FMR1-related variation were explored within the PM group.

Results: PM carriers showed atypical gaze patterns in both tasks. During RAN, the PM group made more refixations (p<.05) and had shorter EVS (p<.10), particularly during the latter portion of the RAN sequence when key executive skills are most heavily taxed (ps<.05). Shorter EVS (i.e., less fluent language processing) was related to poorer social language abilities (but not executive functioning) (r =-.38, p<.01). Greater CGG repeats were also associated with shorter EVS (r=.35, p<.05). In the emotion processing task, the PM group fixated more quickly to the mouth, and spent more time looking at the mouth compared to controls (ps<.01). These atypical gaze patterns were surprisingly related to better social cognitive and social language abilities (rs>|.25|; ps<.05), as well as higher CGG repeats (r=.30, p<.10) in the PM group.

Conclusions: Findings revealed atypical gaze patterns in the PM, consistent with patterns previously observed in the BAP, which were observed across tasks targeting different language and social cognitive processes. Atypical gaze patterns in PM carriers may suggest that common neurocognitive processes are impacted in ASD/the BAP and PM carriers. Associations with CGG expansion suggest that the FMR1 gene may play a role in modulating gaze and cognition. As such, results from this study may elucidate our understanding of the FMR1 gene and its contributions to ASD-related features in the PM and more broadly.

See more of: Rare genetic disorders
See more of: Rare Genetic Disorders