title: Neurofibromatosis type 1 and autism spectrum disorder.
abstract: OBJECTIVE
  To determine the prevalence of autism spectrum disorder (ASD) in Neurofibromatosis Type 1 (NF1).
  
  
  METHODS
  Second-phase population-based epidemiologic study using an allcase NF1 registry in a defined UK 4.1 million population area. A total of 109 (52.7%) of 207 responders from the initial screening phase were grouped by using the parent-rated Social Responsiveness Scale (SRS) as significant ASD (SRS≥76; n = 32), moderate ASD (SRS ≥ 60<76; n = 29), or non-ASD (SRS <60, n = 48). Twenty-three cases from the significant ASD group, 16 from moderate ASD, and 8 from non-ASD (total n = 47), invited proportionately by random selection, were seen for detailed confirmatory ascertainment. Assessments on Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Scale-Generic, and verbal IQ were combined by using standard Collaborative Program for Excellence in Autism criteria into an ASD categorization for each case (ASD, broad ASD with partial features, non-ASD). A preplanned weighted analysis was used to derive prevalence estimates for the whole population.
  
  
  RESULTS
  Fourteen (29.5%) of 47 showed ASD, 13 (27.7%) broad ASD, and 20 (42.5%) non-ASD. The ASD/broad ASD group showed male predominance (1.7:1.0), but did not differ significantly from the non-ASD group on IQ, age, socioeconomic status, inheritance, physical severity, or education. The population prevalence estimate is 24.9% ASD (95% confidence interval 13.1%-42.1%) and 20.8% broad ASD (95% confidence interval 10.0%-38.1%); a total of 45.7% showing some ASD spectrum phenotype.
  
  
  CONCLUSIONS
  Findings indicate high prevalence of ASD in NF1, with implications for clinical practice and further research into NF1 as a single-gene model for autism.
authors.affiliation: FRCPsych, Child and Adolescent Psychiatry, University of Manchester and Manchester Academic Health Sciences Centre, Royal Manchester Children's Hospital, Room 4.308, Jean McFarlane Building, Oxford Rd, Manchester M13 9PL, UK. jonathan.green@manchester.ac.uk.
authors.forename: Shruti
authors.initials: S
authors.lastname: Garg
authors.forename: Jonathan
authors.initials: J
authors.lastname: Green
authors.forename: Kathy
authors.initials: K
authors.lastname: Leadbitter
authors.forename: Richard
authors.initials: R
authors.lastname: Emsley
authors.forename: Annukka
authors.initials: A
authors.lastname: Lehtonen
authors.forename: D Gareth
authors.initials: DG
authors.lastname: Evans
authors.forename: Susan M
authors.initials: SM
authors.lastname: Huson
mesh_terms: D000293:Adolescent; D016009:Chi-Square Distribution; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D002675:Child, Preschool; D004739:England; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009456:Neurofibromatosis 1 / Q000150:complications*; D015995:Prevalence; D011446:Prospective Studies; D011581:Psychological Tests; D012042:Registries
keywords: autism; epidemiology; neurofibromatosis type 1; population