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Emergence and rate of autism in fragile X syndrome across the first years of life

Published online by Cambridge University Press:  09 November 2020

Jane E. Roberts ,
Jessica Bradshaw ,
Elizabeth Will ,
Abigail L. Hogan ,
Samuel McQuillin  and
Kimberly Hills
Jane E. Roberts*
Affiliation:
Department of Psychology, University of South Carolina, Columbia, SC, USA
Jessica Bradshaw
Affiliation:
Department of Psychology, University of South Carolina, Columbia, SC, USA
Elizabeth Will
Affiliation:
Department of Psychology, University of South Carolina, Columbia, SC, USA
Abigail L. Hogan
Affiliation:
Department of Psychology, University of South Carolina, Columbia, SC, USA
Samuel McQuillin
Affiliation:
Department of Psychology, University of South Carolina, Columbia, SC, USA
Kimberly Hills
Affiliation:
Department of Psychology, University of South Carolina, Columbia, SC, USA
*
Author for Correspondence: Dr. Jane Roberts, Department of Psychology, University of South Carolina, 1512 Pendleton Street, Barnwell College #220, Columbia, South Carolina, 29208, USA. E-mail: jerobert@mailbox.sc.edu
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Abstract

Prospective longitudinal studies of idiopathic autism spectrum disorder (ASD) have provided insights into early symptoms and predictors of ASD during infancy, well before ASD can be diagnosed at age 2–3 years. However, research on the emergence of ASD in disorders with a known genetic etiology, contextualized in a developmental framework, is currently lacking. Using a biobehavioral multimethod approach, we (a) determined the rate of ASD in N = 51 preschoolers with fragile X syndrome (FXS) using a clinical best estimate (CBE) procedure with differential diagnoses of comorbid psychiatric disorders and (b) investigated trajectories of ASD symptoms and physiological arousal across infancy as predictors of ASD in preschoolers with FXS. ASD was not diagnosed if intellectual ability or psychiatric disorders better accounted for the symptoms. Our results determined that 60.7% of preschoolers with FXS met the Diagnostic and Statistical Manual of Mental Disorders (fifth edition) (DSM-5) criteria for ASD using the CBE procedure. In addition, 92% of these preschoolers presented with developmental delay and 45.4% also met criteria for psychiatric disorders, either anxiety, ADHD, or both. ASD diagnoses in preschoolers with FXS were predicted by elevated scores on traditional ASD screeners in addition to elevated autonomic arousal and avoidant eye contact from infancy.

Keywords

fragile X syndromeautism spectrum disorderearly identificationinfantsdevelopmental trajectory
Type
Special Section Articles
Information
Development and Psychopathology , Volume 32 , Special Issue 4: Conceptualizing and Interrogating Autism Spectrum Disorder from a Developmental Psychopathology Framework , October 2020 , pp. 1335 - 1352
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Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press

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References

Abbeduto, L., McDuffie, A., & Thurman, A. J. (2014). The fragile X syndrome-autism comorbidity: What do we really know? Frontiers in Genetics, 5, 1–10. doi:10.3389/fgene.2014.00355CrossRefGoogle ScholarPubMed
Abbeduto, L., Thurman, A. J., McDuffie, A., Klusek, J., Feigles, R. T., Ted Brown, W., … Roberts, J. E. (2019). ASD comorbidity in fragile x syndrome: Symptom profile and predictors of symptom severity in adolescent and young adult males. Journal of Autism and Developmental Disorders, 49(3), 960–967. doi:10.1007/s10803-018-3796-2CrossRefGoogle ScholarPubMed
American Psychiatric Association. (2013). The diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: American Psychiatric Association.Google Scholar
Bailey, D. B. J., Raspa, M., Olmsted, M., & Holiday, D. B. (2008). Co-occurring conditions associated with FMR1 gene variations: Findings from a national parent survey. American Journal of Medical Genetics Part A, 146A, 2060–2069. doi:10.1002/ajmg.a.32439CrossRefGoogle ScholarPubMed
Baranek, G. T., David, F. J., Poe, M. D., Stone, W. L., & Watson, L. R. (2006). Sensory experiences questionnaire: Discriminating sensory features in young children with autism, developmental delays, and typical development. Journal of Child Psychology and Psychiatry, 47, 591–601. doi:10.1111/j.1469-7610.2005.01546.xCrossRefGoogle ScholarPubMed
Beauchaine, T. P., Constantino, J. N., & Hayden, E. P. (2018). Psychiatry and developmental psychopathology: Unifying themes and future directions. Comprehensive Psychiatry, 87, 143–152. doi:10.1016/j.comppsych.2018.10.014CrossRefGoogle ScholarPubMed
Berry-Kravis, E. M., Hessl, D., Rathmell, B., Zarevics, P., Cherubini, M., Walton-Bowen, K., … Hagerman, R. J. (2012). Effects of STX209 (arbaclofen) on neurobehavioral function in children and adults with fragile X syndrome: A randomized, controlled, phase 2 trial. Science Translational Medicine, 4, 152ra127.CrossRefGoogle ScholarPubMed
Bishop, S. L., Guthrie, W., Coffing, M., & Lord, C. (2011). Convergent validity of the Mullen scales of early learning and the differential ability scales in children with autism spectrum disorders. American Journal on Intellectual and Developmental Disabilities, 116, 331–343. doi:10.1352/1944-7558-116.5.331CrossRefGoogle ScholarPubMed
Bishop, S. L., Hus, V., Duncan, A., Huerta, M., Gotham, K., Pickles, A., … Lord, C. (2013). Subcategories of restricted and repetitive behaviors in children with autism spectrum disorders. Journal of Autism and Developmental Disorders, 43, 1287–1297. doi:10.1007/s10803-012-1671-0CrossRefGoogle ScholarPubMed
Bodfish, J. W., Symons, F. J., Parker, D. E., & Lewis, M. H. (2000). Varieties of repetitive behavior in autism: Comparisons to mental retardation. Journal of Autism and Developmental Disorders, 30, 237–243. doi:10.1023/A:1005596502855CrossRefGoogle ScholarPubMed
Bosquet, M., & Egeland, B. (2006). The development and maintenance of anxiety symptoms from infancy through adolescence in a longitudinal sample. Development and Psychopathology, 18, 517–550. doi:10.1017/S0954579406060275CrossRefGoogle Scholar
Brewe, A. M., Reisinger, D. L., Adlof, S. M., & Roberts, J. E. (2018). Initiating joint attention use in infants at high-risk for autism spectrum disorder. Journal of Intellectual Disability Research, 62, 842–853. doi:10.1111/jir.12539CrossRefGoogle ScholarPubMed
Bruno, J. L., Romano, D., Mazaika, P., Lightbody, A. A., Hazlett, H. C., Piven, J., & Reiss, A. L. (2017). Longitudinal identification of clinically distinct neurophenotypes in young children with fragile X syndrome. Proceedings of the National Academy of Sciences of the United States of America, 114, 10767–10772. doi:10.1073/pnas.1620994114CrossRefGoogle ScholarPubMed
Bryson, S. E., Zwaigenbaum, L., McDermott, C., Rombough, V., & Brian, J. (2008). The autism observation scale for infants: Scale development and reliability data. Journal of Autism and Developmental Disorders, 38, 731–738. doi:10.1007/s10803-007-0440-yCrossRefGoogle ScholarPubMed
Carter, A. S., Black, D. O., Tewani, S., Connolly, C. E., Kadlec, M. B., & Tager-Flusberg, H. (2007). Sex differences in toddlers with autism spectrum disorders. Journal of Autism and Developmental Disorders, 37, 86–97. doi:10.1007/s10803-006-0331-7CrossRefGoogle ScholarPubMed
Christensen, D. L., Maenner, M. J., Bilder, D., Constantino, J. N., Daniels, J., Durkin, M. S., … Dietz, P. (2019). Prevalence and characteristics of autism spectrum disorder among children aged 4 years—early autism and developmental disabilities monitoring network, seven sites, united states, 2010, 2012, and 2014. MMWR. Surveillance Summaries, 68, 1–19. doi:10.15585/mmwr.ss6802a1CrossRefGoogle Scholar
Cicchetti, D., & Rogosch, F. A. (1996). Equifinality and multifinality in developmental psychopathology. Development and Psychopathology, 8, 597–600. doi:10.1017/S0954579400007318CrossRefGoogle Scholar
Copeland, W. E., Angold, A., Shanahan, L., & Costello, E. J. (2014). Longitudinal patterns of anxiety from childhood to adulthood: The great smoky mountains study. Journal of the American Academy of Child and Adolescent Psychiatry, 53, 21–33. doi:10.1016/j.jaac.2013.09.017CrossRefGoogle ScholarPubMed
Cordeiro, L., Ballinger, E., Hagerman, R. J., & Hessl, D. (2011). Clinical assessment of DSM-IV anxiety disorders in fragile X syndrome: Prevalence and characterization. Journal of Neurodevelopmental Disorders, 3, 57–67. doi:10.1007/s11689-010-9067-yCrossRefGoogle ScholarPubMed
Egger, H. L., Erkanli, A., Keeler, G., Potts, E., Walter, B. K., & Angold, A. (2006). Test-retest reliability of the Preschool Age Psychiatric Assessment (PAPA). Journal of the American Academy of Child and Adolescent Psychiatry, 45, 538–549. doi:10.1097/01.chi.0000205705.71194.b8CrossRefGoogle Scholar
Ezell, J., Hogan, A., Fairchild, A., Hills, K., Klusek, J., Abbeduto, L., & Roberts, J. E. (2019). Prevalence and predictors of anxiety disorders in adolescent and adult males with autism spectrum disorder and fragile X syndrome. Journal of Autism and Developmental Disorders, 49, 1131–1141. doi:10.1007/s10803-018-3804-6CrossRefGoogle ScholarPubMed
Fombonne, E. (2018). Editorial: The rising prevalence of autism. Journal of Child Psychology and Psychiatry, 59, 717–720. doi:10.1111/jcpp.12941CrossRefGoogle ScholarPubMed
Gargaro, B. A., Rinehart, N. J., Bradshaw, J. L., Tonge, B. J., & Sheppard, D. M. (2011, April). Autism and ADHD: How far have we come in the comorbidity debate? Neuroscience and Biobehavioral Reviews, 35, 1081–1088. doi:10.1016/j.neubiorev.2010.11.002CrossRefGoogle ScholarPubMed
Gotham, K., Pickles, A., & Lord, C. (2009). Standardizing ADOS scores for a measure of severity in autism spectrum disorders. Journal of Autism and Developmental Disorders, 39, 693–705. doi:10.1007/s10803-008-0674-3CrossRefGoogle ScholarPubMed
Hagerman, R. J., Hoem, G., & Hagerman, P. (2010). Fragile X and autism: Intertwined at the molecular level leading to targeted treatments. Mol Autism, 1, 12. doi:10.1186/2040-2392-1-12CrossRefGoogle ScholarPubMed
Hagerman, R. J., Protic, D., Rajaratnam, A., Salcedo-Arellano, M. J., Aydin, E. Y., & Schneider, A. (2018). Fragile X-associated neuropsychiatric disorders (FXAND). Frontiers in Psychiatry, 9, 1–9. doi:10.3389/fpsyt.2018.00564CrossRefGoogle Scholar
Hall, S. S., Lightbody, A. A., Hirt, M., Rezvani, A., & Reiss, A. L. (2010). Autism in fragile X syndrome: A category mistake? Journal of the American Academy of Child and Adolescent Psychiatry, 49, 921–933. doi:10.1016/j.jaac.2010.07.001CrossRefGoogle ScholarPubMed
Harris, S. W., Hessl, D., Goodlin-Jones, B., Ferranti, J., Bacalman, S., Barbato, I., … Hagerman, R. J. (2008). Autism profiles of males with fragile X syndrome. American Journal on Mental Retardation, 113, 427–438. doi:10.1352/2008.113:427-438CrossRefGoogle ScholarPubMed
Havdahl, K. A., Hus Bal, V., Huerta, M., Pickles, A., Øyen, A. S., Stoltenberg, C., … Bishop, S. L. (2016). Multidimensional influences on autism symptom measures: Implications for use in etiological research. Journal of the American Academy of Child and Adolescent Psychiatry, 55, 1054–1063. doi:10.1016/j.jaac.2016.09.490CrossRefGoogle ScholarPubMed
Hazlett, H. C., Poe, M. D., Lightbody, A. A., Styner, M., MacFall, J. R., Reiss, A. L., & Piven, J. (2012). Trajectories of early brain volume development in fragile X syndrome and autism. Journal of the American Academy of Child and Adolescent Psychiatry, 51, 921–933. doi:10.1016/j.jaac.2012.07.003CrossRefGoogle ScholarPubMed
Heilman, K. J., Bal, E., Bazhenova, O. V., Sorokin, Y., Perlman, S. B., Hanley, M. C., & Porges, S. W. (2008). Physiological responses to social and physical challenges in children: Quantifying mechanisms supporting social engagement and mobilization behaviors. Developmental Psychobiology, 50, 171–182.CrossRefGoogle ScholarPubMed
Hernandez, R. N., Feinberg, R. L., Vaurio, R., Passanante, N. M., Thompson, R. E., & Kaufmann, W. E. (2009). Autism spectrum disorder in fragile X syndrome: A longitudinal evaluation. American Journal of Medical Genetics Part A, 149A, 1125–1137. doi:10.1002/ajmg.a.32848CrossRefGoogle ScholarPubMed
Hiller, R. M., Young, R. L., & Weber, N. (2014). Sex differences in autism spectrum disorder based on DSM-5 criteria: Evidence from clinician and teacher reporting. Journal of Abnormal Child Psychology, 42, 1381–1393. doi:10.1007/s10802-014-9881-xCrossRefGoogle ScholarPubMed
Hogan, A. L., Caravella, K. E., Ezell, J., Rague, L., Hills, K., & Roberts, J. E. (2017). Autism spectrum disorder symptoms in infants with fragile x syndrome: A prospective case series. Journal of Autism and Developmental Disorders, 47, 1628–1644. doi:1007/s10803-017-3081-9CrossRefGoogle ScholarPubMed
Jacob, S., Wolff, J. J., Steinbach, M. S., Doyle, C. B., Kumar, V., & Elison, J. T. (2019, December 1). Neurodevelopmental heterogeneity and computational approaches for understanding autism. Translational Psychiatry, 9, 1–12. doi:10.1038/s41398-019-0390-0CrossRefGoogle ScholarPubMed
Kaufmann, W. E., Kidd, S. A., Andrews, H. F., Budimirovic, D. B., Esler, A., Haas-Givler, B., … Berry-Kravis, E. (2017). Autism spectrum disorder in fragile X syndrome: Cooccurring conditions and current treatment. Pediatrics, 139, S194–S206. doi:10.1542/peds.2016-1159FCrossRefGoogle ScholarPubMed
Kerns, C. M., Kendall, P. C., Berry, L., Souders, M. C., Franklin, M. E., Schultz, R. T., … Herrington, J. (2014). Traditional and atypical presentations of anxiety in youth with autism spectrum disorder. Journal of Autism and Developmental Disorders, 44, 2851–2861. doi:10.1007/s10803-014-2141-7CrossRefGoogle ScholarPubMed
Kerns, C. M., Newschaffer, C. J., & Berkowitz, S. J. (2015). Traumatic childhood events and autism spectrum disorder. Journal of Autism and Developmental Disorders, 45, 3475–3486. doi:10.1007/s10803-015-2392-yCrossRefGoogle ScholarPubMed
Kirkovski, M., Enticott, P. G., & Fitzgerald, P. B. (2013). A review of the role of female gender in autism spectrum disorders. J Autism Dev Disord, 43, 2584–2603. doi:10.1007/s10803-013-1811-1CrossRefGoogle ScholarPubMed
Klusek, J., Martin, G. E., & Losh, M. (2014). Consistency between research and clinical diagnoses of autism among boys and girls with fragile X syndrome. Journal of Intellectual Disability Research, 58, 940–952. doi:10.1111/jir.12121CrossRefGoogle ScholarPubMed
Knott, C., Will, E. A., & Roberts, J. E. (2019). Sensory Processing in Relation to Sleep Disturbances in Young Children with Autism Spectrum Disorder and Fragile X Syndrome with and without Comorbid Autism Spectrum Disorder. Annual Meeting of the International Society for Autism Research, Montreal, Quebec.Google Scholar
Lee, M., Martin, G. E., Berry-Kravis, E., & Losh, M. (2016). A developmental, longitudinal investigation of autism phenotypic profiles in fragile X syndrome. Journal of Neurodevelopmental Disorders, 8, 47. doi:10.1186/s11689-016-9179-0CrossRefGoogle ScholarPubMed
Lord, C., Petkova, E., Hus, V., Gan, W., Lu, F., Martin, D. M., … Risi, S. (2012). A multisite study of the clinical diagnosis of different autism spectrum disorders. Archives of General Psychiatry, 69, 306–313. doi:10.1001/archgenpsychiatry.2011.148CrossRefGoogle ScholarPubMed
Lord, C., Risi, S., DiLavore, P. S., Shulman, C., Thurm, A., & Pickles, A. (2006). Autism from 2 to 9 years of age. Archives of General Psychiatry, 63, 694–701. doi:10.1001/archpsyc.63.6.694CrossRefGoogle ScholarPubMed
Lord, C., Rutter, M., DiLavore, P., Risi, S., Gotham, K., & Bishop, S. (2012). Autism diagnostic observation schedule (2nd ed.), ADOS-2. Torrance, CA: Western Psychological Services.Google Scholar
Lord, C., Rutter, M., & Le Couteur, A. (1994). Autism diagnostic interview-revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism and Developmental Disorders, 24, 659–685.CrossRefGoogle ScholarPubMed
Lundstrom, S., Chang, Z., Kerekes, N., Gumpert, C. H., Rastam, M., Gillberg, C., … Anckarsater, H. (2011). Autistic-like traits and their association with mental health problems in two nationwide twin cohorts of children and adults. Psychological Medicine, 41(11), 2423–2433.CrossRefGoogle ScholarPubMed
McCormick, C. E. B., Sheinkopf, S. J., Levine, T. P., LaGasse, L. L., Tronick, E., & Lester, B. L. (2018). Diminished respiratory sinus arrhythmia response in infants later diagnosed with autism spectrum disorder. Autism Research, 11, 726–731. doi:10.1002/aur.1929CrossRefGoogle ScholarPubMed
McDuffie, A., Abbeduto, L., Lewis, P., Kover, S., Kim, J. S., Weber, A., & Brown, W. T. (2010). Autism spectrum disorder in children and adolescents with fragile X syndrome: Within-syndrome differences and age-related changes. American Journal on Intellectual and Developmental Disabilities, 115, 307–326. doi:10.1352/1944-7558-115.4.307CrossRefGoogle ScholarPubMed
Merenstein, S. A., Sobesky, W. E., Taylor, A. K., Riddle, J. E., Tran, H. X., & Hagerman, R. J. (1996). Molecular-clinical correlations in males with an expanded FMR1 mutation. American Journal of Medical Genetics, 64, 388–394.3.0.CO;2-9>CrossRefGoogle ScholarPubMed
Moskowitz, LJ, Will, EA, Conner, JB, Black, J, & Roberts, JE. (2020). Restricted and repetitive behaviors in males and females with fragile X syndrome: Developmental trajectories in toddlers through young adults developmental trajectories of restricted and repetitive behaviors in males and females with fragile X syndrome. Journal of Autism and Developmental Disorders. Advance online publication. doi:10.1007/s10803-020-04459-7CrossRefGoogle ScholarPubMed
Mullen, E. (1995). Mullen scales of early learning. Circle Pines, MN: American Guidance Service.Google Scholar
Muthen, L. K., & Muthen, B. O. (2017). Mplus User‘s Guide. Los Angeles, CA: Muthen & Muthen.Google Scholar
Ozonoff, S., Young, G. S., Landa, R. J., Brian, J., Bryson, S., Charman, T., … Iosif, A.-M. (2015). Diagnostic stability in young children at risk for autism spectrum disorder: A baby siblings research consortium study. Journal of Child Psychology and Psychiatry, and Allied Disciplines, 56, 988–998. doi:10.1111/jcpp.12421CrossRefGoogle ScholarPubMed
Patriquin, M. A., Hartwig, E. M., Friedman, B. H., Porges, S. W., & Scarpa, A. (2019). Autonomic response in autism spectrum disorder: Relationship to social and cognitive functioning. Biological Psychology, 145, 185–197. doi:10.1016/j.biopsycho.2019.05.004CrossRefGoogle ScholarPubMed
Paulus, F. W., Backes, A., Sander, C. S., Weber, M., & von Gontard, A. (2015). Anxiety disorders and behavioral inhibition in preschool children: A population-based study. Child Psychiatry and Human Development, 46, 150–157. doi:10.1007/s10578-014-0460-8CrossRefGoogle ScholarPubMed
Porges, S. W., & Bohrer, R. E. (1990). Analyses of periodic processes in psychophysiological research. In Cacioppo, J. T. & Tassinary, L. G. (Eds.), Principles of Psychophysiology: Physical, Social and Inferential Elements (pp. 708–753). New York: Cambridge University Press.Google Scholar
Rague, L., Caravella, K., Tonnsen, B. L., Klusek, J., & Roberts, J. E. (2018). Early gesture use in fragile X syndrome. Journal of Intellectual Disability Research, 62, 625–636. doi:10.1111/jir.12498CrossRefGoogle ScholarPubMed
R Core Team. (2019). R: A language and environment for statistical computing.Google Scholar
Roberts, J. E., Crawford, H., Hogan, A. L., Fairchild, A., Tonnsen, B. L., Brewe, A., … Abbeduto, L. (2019). Social avoidance emerges in infancy and persists into adulthood in fragile x syndrome. Journal of Autism and Developmental Disorders, 49, 3753–3766. doi:10.1007/s10803-019-04051-8CrossRefGoogle ScholarPubMed
Roberts, J. E., Crawford, H., Will, E. A., Hogan, A. L., McQuillin, S., Tonnsen, B. L., … Brewe, A. M. (2019). Infant social avoidance predicts autism but not anxiety in fragile X syndrome. Frontiers in Psychiatry, 10, 199. doi:10.3389/fpsyt.2019.00199CrossRefGoogle Scholar
Roberts, J. E., Ezell, J. E., Fairchild, A. J., Klusek, J., Thurman, A. J., McDuffie, A., & Abbeduto, L. (2018). Biobehavioral composite of social aspects of anxiety in young adults with fragile X syndrome contrasted to autism spectrum disorder. American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics, 177, 665–675. doi:10.1002/ajmg.b.32674CrossRefGoogle ScholarPubMed
Roberts, J. E., Tonnsen, B. L., McCary, L. M., Caravella, K. E., & Shinkareva, S. V. (2016). Brief report: Autism symptoms in infants with fragile x syndrome. Journal of Autism and Developmental Disorders, 46, 3830–3837. doi:10.1007/s10803-016-2903-5CrossRefGoogle ScholarPubMed
Roberts, J. E., Tonnsen, B. L., Robinson, A., & Shinkareva, S. V. (2012). Heart activity and autistic behavior in infants and toddlers with fragile X syndrome. American Journal on Intellectual and Developmental Disabilities, 117, 90–102. doi:10.1352/1944-7558-117.2.90CrossRefGoogle ScholarPubMed
Roberts, J. E., Weisenfeld, L. H., Hatton, D., Heath, M., & Kaufmann, W. E. (2007). Social approach and autistic behavior in children with fragile X syndrome. Journal of Autism and Developmental Disorders, 37, 1748–1760.CrossRefGoogle ScholarPubMed
Robins, D. L., Fein, D., Barton, M. L., & Green, J. A. (2001). The modified checklist for autism in toddlers: An initial study investigating the early detection of autism and pervasive developmental disorders. Journal of Autism and Developmental Disorders, 31, 131–144.CrossRefGoogle ScholarPubMed
Rogers, S., Wehner, E., & Hagerman, R. J. (2001). The behavioral phenotype in fragile X: Symptoms of autism in very young children with fragile X syndrome, idiopathic autism, and other developmental disorders. Journal of Developmental and Behavioral Pediatrics, 22, 409–417.CrossRefGoogle ScholarPubMed
Rutter, M., LeCouteur, A., & Lord, C. (2003). Autism diagnostic interview–revised (ADI–R) manual. Los Angeles: Western Psychological Services.Google Scholar
Salazar, F., Baird, G., Chandler, S., Tseng, E., O'sullivan, T., Howlin, P., … Simonoff, E. (2015). Co-occurring psychiatric disorders in preschool and elementary school-aged children with autism spectrum disorder. Journal of Autism and Developmental Disorders, 45, 2283–2294. doi:10.1007/s10803-015-2361-5CrossRefGoogle ScholarPubMed
Schopler, E., Van Bourgondien, M., Wellman, J., & Love, S. (2010). Childhood autism rating scale (2nd ed.) (CARS-2). Los Angeles, CA: Western Psychological Services.Google Scholar
Sheinkopf, S. J., Levine, T. P., McCormick, C. E. B., Puggioni, G., Conradt, E., Lagasse, L. L., & Lester, B. M. (2019). Developmental trajectories of autonomic functioning in autism from birth to early childhood. Biological Psychology, 142, 13–18. doi:10.1016/j.biopsycho.2019.01.003CrossRefGoogle Scholar
Shumway, S., Farmer, C., Thurm, A., Joseph, L., Black, D., & Golden, C. (2012). The ADOS calibrated severity score: Relationship to phenotypic variables and stability over time. Autism Research, 5, 267–276. doi:10.1002/aur.1238CrossRefGoogle ScholarPubMed
Simberlund, J., & Veenstra-VanderWeele, J. (2019). Fragile X: Autism in the setting of a known genetic syndrome. In Pediatric Neuropsychiatry (pp. 67–74). doi:10.1007/978-3-319-94998-7_7CrossRefGoogle Scholar
Simonoff, E., Pickles, A., Charman, T., Chandler, S., Loucas, T., & Baird, G. (2008). Psychiatric disorders in children with autism spectrum disorders: Prevalence, comorbidity, and associated factors in a population-derived sample. Journal of the American Academy of Child and Adolescent Psychiatry, 47, 921–929. doi:10.1097/CHI.0b013e318179964fCrossRefGoogle Scholar
Sparrow, S. S., Cicchetti, D. V., & Balla, D. A. (2005). Vineland adaptive behavior scales (Vineland II) (2nd ed). San Antonio, TX: Pearson.Google Scholar
Sullivan, K., Hatton, D., Hammer, J., Sideris, J., Hooper, S., Ornstein, P., & Bailey, D. (2006). ADHD symptoms in children with FXS. American Journal of Medical Genetics Part A, 140A, 2275–2288. doi:10.1002/ajmg.a.31388CrossRefGoogle ScholarPubMed
Swanson, M. R., Wolff, J. J., Shen, M. D., Styner, M., Estes, A., Gerig, G., … Hazlett, H. C. (2018). Development of white matter circuitry in infants with fragile x syndrome. JAMA Psychiatry, 75, 505–513. doi:10.1001/jamapsychiatry.2018.0180CrossRefGoogle ScholarPubMed
Thurm, A., Farmer, C., Salzman, E., Lord, C., & Bishop, S. (2019). State of the field: Differentiating intellectual disability from autism spectrum disorder. Frontiers in Psychiatry, 10, 526. doi:10.3389/fpsyt.2019.00526CrossRefGoogle ScholarPubMed
Tonnsen, B. L., Richards, J. E., & Roberts, J. E. (2018). Heart rate-defined sustained attention in infants at risk for autism. Journal of Neurodevelopmental Disorders, 10, 7. doi:10.1186/s11689-018-9224-2CrossRefGoogle ScholarPubMed
Tonnsen, B. L., Shinkareva, S. V., Deal, S. C., Hatton, D. D., & Roberts, J. E. (2013). Biobehavioral indicators of social fear in young children with fragile X syndrome. American Journal on Intellectual and Developmental Disabilities, 118, 447–459. doi:10.1352/1944-7558-118.6.447CrossRefGoogle ScholarPubMed
Warren, Z., McPheeters, M. L., Sathe, N., Foss-Feig, J. H., Glasser, A., & Veenstra-VanderWeele, J. (2011). A systematic review of early intensive intervention for autism spectrum disorders. Pediatrics, 127, e1303–e1311. doi:10.1542/peds.2011-0426CrossRefGoogle ScholarPubMed
Wheeler, A. C., Mussey, J., Villagomez, A., Bishop, E., Raspa, M., Edwards, A., … Bailey, D. B. (2015). DSM-5 changes and the prevalence of parent-reported autism spectrum symptoms in fragile x syndrome. Journal of Autism and Developmental Disorders, 45, 816–829. doi:10.1007/s10803-014-2246-zCrossRefGoogle ScholarPubMed
Will, E. A., Bishop, S. L., & Roberts, J. E. (2019). Developmental divergence: Motor trajectories in children with fragile X syndrome with and without co-occurring autism. Journal of Neurodevelopmental Disorders, 11, 1–10. doi:10.1186/s11689-019-9281-1CrossRefGoogle ScholarPubMed
Zwaigenbaum, L., Bryson, S., Rogers, T., Roberts, W., Brian, J., & Szatmari, P. (2005). Behavioral manifestations of autism in the first year of life. International Journal of Developmental Neuroscience, 23, 143–152. doi:10.1016/j.ijdevneu.2004.05.001CrossRefGoogle ScholarPubMed