title: Lack of cognitive impairment in first-degree relatives of children with pervasive developmental disorders.
abstract: OBJECTIVE
  The objective of this study was to test the hypothesis that mild cognitive impairments aggregate in the unaffected first-degree relatives of probands with autism or pervasive developmental disorders (PDD).
  
  
  METHODS
  The unaffected siblings and parents of 52 PDD probands and 33 Down syndrome and low birth weight controls were administered a battery of psychometric tests. The tests included measures previously found to be depressed in siblings of autistic children as well as cognitive deficits seen in PDD subjects of normal IQ. In addition, the Vineland Adaptive Behavior Scales were administered to siblings to measure the social-communication impairments found in PDD.
  
  
  RESULTS
  Neither the siblings nor parents of the PDD probands demonstrated lower cognitive or adaptive behavior scores compared with controls. Developmental histories did not reveal greater rates of social, cognitive, or language delays, nor was there evidence to suggest that relatives of subgroups of PDD probands were different from each other.
  
  
  CONCLUSIONS
  These findings indicate that, apart from relatives with PDD, cognitive and social impairments do not aggregate in the families of PDD probands.
authors.affiliation: Department of Psychiatry, McMaster University, Hamilton, Ontario, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Szatmari
authors.forename: M B
authors.initials: MB
authors.lastname: Jones
authors.forename: L
authors.initials: L
authors.lastname: Tuff
authors.forename: G
authors.initials: G
authors.lastname: Bartolucci
authors.forename: S
authors.initials: S
authors.lastname: Fisman
authors.forename: W
authors.initials: W
authors.lastname: Mahoney
mesh_terms: D000293:Adolescent; D001321:Autistic Disorder / Q000150:complications; D002648:Child; D002653:Child Behavior Disorders / Q000150:complications; D002659:Child Development Disorders, Pervasive / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D003071:Cognition; D003072:Cognition Disorders / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D010290:Parents; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics