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.
- ABC —
- Adaptive Behavior Composite
- ADHD —
- attention-deficit/hyperactivity disorder
- ADI-R —
- Autism Diagnostic Interview-Revised
- ADOS-G —
- Autism Diagnostic Observation Scale-Generic
- ASD —
- autism spectrum disorder
- CPEA —
- Collaborative Program for Excellence in Autism
- NF1 —
- Neurofibromatosis Type 1
- Ras —
- Rat Sarcoma protein
- SES —
- socioeconomic status
- SRS —
- Social Responsiveness Scale
- VABS —
- Vineland Adaptive Behavior Scale
- WASI —
- Wechsler Abbreviated Scale of Intelligence
- Accepted September 10, 2013.
- Copyright © 2013 by the American Academy of Pediatrics