2016 Gatlinburg Conference Poster
PS-20
Title: Early Gesture Use in 12 Month Old Infants with Fragile X Syndrome, Infant Siblings of Children with Autism and Typically
Developing Infants
Authors: Lisa Rague, Kelly E. Caravella, Jessica Klusek, Jane E. Roberts
Introduction: Fragile X syndrome (FXS) is a genetically-based neurodevelopmental disorder and the leading known cause of
intellectual disability. Many individuals with FXS show deficits across a range of domains, particularly in the area of
communication (Roberts, Hatton & Bailey, 2001). Communication deficits in FXS range from impairment in syntactic production
to pragmatic language difficulties (Roberts, Mirrett, Anderson, Burchinal & Neebe, 2002). One area that is important to the
development of language is gesture use. Individuals with FXS have been shown to demonstrate a relative weakness in gesture
use as early as 21 months (Roberts, Mirrett, Anderson, Burchinal & Neebe, 2002); however, little research has examined gesture
use in FXS earlier in development, during the time gestures begin to emerge in typically developing (TD) children. This study
investigates early gesture use in 12 month old infants with FXS as compared to TD infants, as well as infants who are at risk for
early social communication deficits (i.e. infant siblings of children with autism (ASIB); Yirmiya et al., 2006).
Methods: The sample includes 70 males recruited through two longitudinal studies conducted at UNC-Chapel Hill and at the
University of South Carolina. Participants included 25 infants with FXS (Mage = 12.53 months, SDage = 0.81), 23 ASIBs (Mage =
12.78 months, SDage = 1.16) and 22 TD infants (Mage = 12.15 months, SDage = 0.85). To measure developmental level and
gesture use, the Mullen Scales of Early Learning (MSEL) and the MacArthur-Bates Communication Development Inventory (CDI)
were used respectively. Analyses were run in R.
Results: An ANCOVA was run to determine whether differences in group means (TD = 10.63, ASIB = 9.11, FXS = 6.35) of Early
Gesture scores on the CDI existed at 12 months of age, controlling for nonverbal ability using the Visual Reception subdomain of
the MSEL. ANCOVA results showed that there were significant differences in group means of Early Gesture scores (F(2,66) =
9.38, p < 0.001). Post-hoc analyses of group differences showed that the FXS group used 5.78 less gestures than the TD group (p
< 0.001) and 4.28 less gestures than the ASIB group (p < 0.001). Differences in amount of early gesture use between the ASIB
and TD groups were not statistically significant (p = 0.26).
Discussion: Infants with FXS showed significant deficits in amount of gesture use as early as 12 months of age when compared
to both TD infants, and infants at high risk of developing communication disorders, and these differences are not simply due to
the general developmental delay typically observed in individuals with FXS. ASIB infants were not delayed in gesture use at 12
months, compared to the TD group. These findings highlight the importance of targeting gesture use in interventions specifically
in FXS. Further research is needed to determine the effect of these early gesture deficits in FXS on later communication
development.
References/Citations:
• Sherman, S., Pletcher, B. A., & Driscoll, D. A. (2005). Fragile X syndrome: diagnostic and carrier testing. Genetics in
Medicine, 7(8), 584-587.
• Roberts, J. E., Hatton, D. D., & Bailey, D. B. (2001). Development and behavior of male toddlers with fragile X syndrome.
Journal of Early Intervention, 24(3), 207-223.
• Roberts, J. E., Mirrett, P., Anderson, K., Burchinal, M., & Neebe, E. (2002). Early communication, symbolic behavior, and
social profiles of young males with fragile X syndrome. American Journal of Speech-Language Pathology,11(3), 295-304.
• Yirmiya, N., Gamliel, I., Pilowsky, T., Feldman, R., Baron‐Cohen, S., & Sigman, M. (2006). The development of siblings of
children with autism at 4 and 14 months: Social engagement, communication, and cognition. Journal of Child Psychology
and Psychiatry, 47(5), 511-523.