title: Executive function in probands with autism with average IQ and their unaffected first-degree relatives.
abstract: OBJECTIVE
  This study aimed to characterize executive function (EF) in pedigrees of children with autism spectrum disorder (ASD) and average IQ. The authors examined the hypothesis that deficits in EF relate to lower levels of adaptive functioning, and they assessed evidence for a cognitive extended phenotype in unaffected relatives in a large, well-characterized sample.
  
  
  METHODS
  Proband EF was assessed by parent-report questionnaires (Behavior Rating Inventory of Executive Functioning [BRIEF], n = 109) and child neuropsychological tests (Delis-Kaplan Executive Functioning System [D-KEFS], n = 35). EF also was examined in parents (D-KEFS, n = 335) and unaffected siblings (BRIEF, n = 114; D-KEFS, n = 57). Adaptive functioning was assessed by the Vineland Adaptive Behavior Scales-II (n = 155). All data were obtained from the Autism Consortium Clinical Genetics Database.
  
  
  RESULTS
  Individuals with ASD showed important EF weaknesses. Multiple regression analyses showed that parent-reported EF deficits were related to profound decreases in adaptive functioning even after controlling for age, IQ, and severity of ASD symptoms. Parent-reported EF also was related to adaptive skills in preschoolers. First-degree unaffected relatives did not demonstrate difficulties with EF compared with normative data.
  
  
  CONCLUSIONS
  In this study, EF impairments do not appear to relate to broad familial risk factors for ASD but may be associated with factors relevant to the expression of ASD in probands. Results support the benefits of EF assessment as a way to identify potential therapeutic targets that could lead to improved adaptive behavior in children with ASD and average IQ.
authors.affiliation: Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital, Brown University Medical School, and the Neurodevelopmental Center, Memorial Hospital of Rhode Island.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: McLean
authors.affiliation: Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital, and Brown University Medical School.
authors.forename: Ashley
authors.initials: A
authors.lastname: Johnson Harrison
authors.affiliation: Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital, and Brown University Medical School.
authors.forename: Eric
authors.initials: E
authors.lastname: Zimak
authors.affiliation: Boston University School of Medicine and the Autism Consortium.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Joseph
authors.affiliation: Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital, Brown University Medical School, the Brown Institute for Brain Science, Brown University, and the Autism Consortium. Electronic address: eric_morrow@brown.edu.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Morrow
mesh_terms: D000293:Adolescent; D000067877:Autism Spectrum Disorder / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008297:Male; D010375:Pedigree
keywords: IQ; adaptive functioning; autism spectrum disorder; executive functioning; pedigree