title: Repetitive behavior in 12-month-olds later classified with autism spectrum disorder.
abstract: OBJECTIVE
  As compared to the utility of early emerging social communicative risk markers for predicting a later diagnosis of autism spectrum disorder (ASD), less is known about the relevance of early patterns of restricted and repetitive behaviors. We examined patterns of stereotyped motor mannerisms and repetitive manipulation of objects in 12-month-olds at high and low risk for developing ASD, all of whom were assessed for ASD at 24 months.
  
  
  METHODS
  Observational coding of repetitive object manipulation and stereotyped motor behaviors in digital recordings of the Communication and Symbolic Behavior Scales was conducted using the Repetitive and Stereotyped Movement Scales for 3 groups of 12-month-olds: low-risk infants (LR, n = 53); high-familial-risk infants who did not meet diagnostic criteria for ASD at 24 months (HR-negative, n = 75); and high-familial-risk infants who met diagnostic criteria for ASD at 24 months (HR-ASD, n = 30).
  
  
  RESULTS
  The HR-ASD group showed significantly more stereotyped motor mannerisms than both the HR-negative group (p = .025) and the LR group (p = .001). The HR-ASD and HR-negative groups demonstrated statistically equivalent repetitive object manipulation scores (p = .431), and both groups showed significantly more repetitive object manipulation than the LR group (p < .040). Combining the motor and object stereotypy scores into a Repetitive and Stereotyped Movement Scales (RSMS) composite yielded a disorder-continuum effect such that each group was significantly different from one another (LR < HR-negative < HR-ASD).
  
  
  CONCLUSIONS
  These results suggest that targeted assessment of repetitive behavior during infancy may augment early ASD identification efforts.
authors.affiliation: Institute of Child Development at the University of Minnesota, Minneapolis. Electronic address: jtelison@umn.edu.
authors.forename: Jed T
authors.initials: JT
authors.lastname: Elison
authors.affiliation: Carolina Institute for Developmental Disabilities and the University of North Carolina (UNC) at Chapel Hill, NC.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Wolff
authors.affiliation: University of North Carolina at Chapel Hill.
authors.forename: J Steven
authors.initials: JS
authors.lastname: Reznick
authors.affiliation: Washington University in St. Louis.
authors.forename: Kelly N
authors.initials: KN
authors.lastname: Botteron
authors.affiliation: University of Washington, Seattle.
authors.forename: Annette M
authors.initials: AM
authors.lastname: Estes
authors.affiliation: Carolina Institute for Developmental Disabilities and the University of North Carolina (UNC) at Chapel Hill, NC.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Gu
authors.affiliation: Carolina Institute for Developmental Disabilities and the University of North Carolina (UNC) at Chapel Hill, NC.
authors.forename: Heather C
authors.initials: HC
authors.lastname: Hazlett
authors.affiliation: Carolina Institute for Developmental Disabilities and the University of North Carolina (UNC) at Chapel Hill, NC.
authors.forename: Adriane J
authors.initials: AJ
authors.lastname: Meadows
authors.affiliation: Dr. Paterson is with the Children's Hospital of Philadelphia.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Paterson
authors.affiliation: Dr. Zwaigenbaum is with the University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Lonnie
authors.initials: L
authors.lastname: Zwaigenbaum
authors.affiliation: Carolina Institute for Developmental Disabilities and the University of North Carolina (UNC) at Chapel Hill, NC.
authors.forename: Joseph
authors.initials: J
authors.lastname: Piven
mesh_terms: D002659:Child Development Disorders, Pervasive / Q000145:classification* / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013239:Stereotyped Behavior
keywords: autism; development; infant siblings; motor stereotypies; repetitive behavior