title: Neurobehavioral abnormalities in first-degree relatives of individuals with autism.
abstract: BACKGROUND
  Studying sensorimotor and neurocognitive impairments in unaffected family members of individuals with autism may help identify familial pathophysiological mechanisms associated with the disorder.
  
  
  OBJECTIVE
  To determine whether atypical sensorimotor or neurocognitive characteristics associated with autism are present in first-degree relatives of individuals with autism.
  
  
  METHODS
  Case-control comparison of neurobehavioral functions.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  Fifty-seven first-degree relatives of individuals with autism and 40 age-, sex-, and IQ-matched healthy control participants (aged 8-54 years).
  
  
  METHODS
  Oculomotor tests of sensorimotor responses (saccades and smooth pursuit); procedural learning and response inhibition; neuropsychological tests of motor, memory, and executive functions; and psychological measures of social behavior, communication skills, and obsessive-compulsive behaviors.
  
  
  RESULTS
  On eye movement testing, family members demonstrated saccadic hypometria, reduced steady-state pursuit gain, and a higher rate of voluntary response inhibition errors relative to controls. They also showed lateralized deficits in procedural learning and open-loop pursuit gain (initial 100 milliseconds of pursuit) and increased variability in the accuracy of large-amplitude saccades that were confined to rightward movements. In neuropsychological studies, only executive functions were impaired relative to those of controls. Family members reported more communication abnormalities and obsessive-compulsive behaviors than controls. Deficits across oculomotor, neuropsychological, and psychological domains were relatively independent from one another.
  
  
  CONCLUSIONS
  Family members of individuals with autism demonstrate oculomotor abnormalities implicating pontocerebellar and frontostriatal circuits and left-lateralized alterations of frontotemporal circuitry and striatum. The left-lateralized alterations have not been identified in other neuropsychiatric disorders and are of interest given atypical brain lateralization and language development associated with the disorder. Similar oculomotor deficits have been reported in individuals with autism, suggesting that they may be familial and useful for studies of neurophysiological and genetic mechanisms in autism.
authors.affiliation: Center for Cognitive Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Mosconi
authors.forename: Margaret
authors.initials: M
authors.lastname: Kay
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: D'Cruz
authors.forename: Stephen
authors.initials: S
authors.lastname: Guter
authors.forename: Kush
authors.initials: K
authors.lastname: Kapur
authors.forename: Carol
authors.initials: C
authors.lastname: Macmillan
authors.forename: Lisa D
authors.initials: LD
authors.lastname: Stanford
authors.forename: John A
authors.initials: JA
authors.lastname: Sweeney
mesh_terms: D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D056344:Executive Function / Q000502:physiology; D005133:Eye Movements / Q000235:genetics / Q000502:physiology; D005190:Family / Q000523:psychology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000235:genetics; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D011698:Pursuit, Smooth / Q000235:genetics / Q000502:physiology; D012438:Saccades / Q000235:genetics / Q000502:physiology