Autism is a devastating and common developmental disorder and a major public health concern. Early detection of autism in high risk infants is critical to these children, their families, and the systems that support them. Fragile X syndrome (FXS) is the leading genetic cause of autism, and both FXS and the FMR1 premutation (FXpm) are highly associated with autism. Despite the high association of autism and FMR1 gene mutations, no study has examined early indicators of autism in FXS or FXpm or examined specificity of early autism indicators in FX to idiopathic (non-FX) autism. This application "Emergence and Stability of Autism in Fragile X Syndrome" proposes a longitudinal prospective study of the early autism features in infants with FXS and FXpm at 9, 12, and 24 in contrast to infants with an older sibling diagnosed with autism (hereafter referred to as "ASIBS") and typical controls (TD). This application takes advantage of recent scientific advances in the identification of autism in the first 2 years of life, characterization of the FXS and FXpm-autism co-morbidity and findings from developmental neuroscience to identify underlying physiological mechanisms associated with early emerging autistic features (e.g., attention). This work will advance our understanding of the progression of autism features during the key risk transition period for two conditions of major health importance: FX and autism. In this project, we will use a combined behavioral, both standardized and laboratory measures, and biomarker approach focused on autistic behavior as a continuum rather than rigid diagnostic categories.

Public Health Relevance

Autism is a Devastating and Common Developmental Disorder that is a Major Public Health Concern. With a prevalence of ~1:110 (1:70 males) and a cost of $35 billion per year, the early detection of autism in high risk infants is critical to these children, their families and the systems that support them.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
Research Project (R01)
Project #
Application #
Study Section
Behavioral Genetics and Epidemiology Study Section (BGES)
Program Officer
Gilotty, Lisa
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of South Carolina at Columbia
Schools of Arts and Sciences
United States
Zip Code
Klusek, Jessica; Roberts, Jane E; Losh, Molly (2015) Cardiac autonomic regulation in autism and Fragile X syndrome: a review. Psychol Bull 141:141-75
Klusek, Jessica; Hunt, Anna W; Mirrett, Penny L et al. (2015) Reading and phonological skills in boys with fragile X syndrome. J Autism Dev Disord 45:1699-711
Adlof, Suzanne M; Klusek, Jessica; Shinkareva, Svetlana V et al. (2015) Phonological awareness and reading in boys with fragile X syndrome. J Child Psychol Psychiatry 56:30-9
Roberts, Jane E; Tonnsen, Bridgette L; Robinson, Marissa et al. (2014) Temperament factor structure in fragile X syndrome: the children's behavior questionnaire. Res Dev Disabil 35:563-71
Tonnsen, Bridgette L; Grefer, Marjorie L; Hatton, Deborah D et al. (2014) Developmental trajectories of attentional control in preschool males with fragile X syndrome. Res Dev Disabil 36C:62-71
Tonnsen, Bridgette L; Cornish, Kim M; Wheeler, Anne C et al. (2014) Maternal predictors of anxiety risk in young males with fragile X. Am J Med Genet B Neuropsychiatr Genet 165B:399-409
Roberts, Jane E; Long, Anna C J; McCary, Lindsay M et al. (2013) Cardiovascular and behavioral response to auditory stimuli in boys with fragile X syndrome. J Pediatr Psychol 38:276-84
Tonnsen, Bridgette L; Malone, Patrick S; Hatton, Deborah D et al. (2013) Early negative affect predicts anxiety, not autism, in preschool boys with fragile X syndrome. J Abnorm Child Psychol 41:267-80