Autistic-spectrum disorders in Down syndrome: further delineation and distinction from other behavioral abnormalities.

Mark McIntosh,'s picture
PubMed URL:
Kaufmann WE
Author List: 
Carter JC
Capone GT
Gray RM
Cox CS
Kaufmann WE
Am J Med Genet B Neuropsychiatr Genet
PubMed ID: 
The present study extends our previous work characterizing the behavioral features of autistic-spectrum disorder (ASD) in Down syndrome (DS) using the Aberrant Behavior Checklist (ABC) and Autism Behavior Checklist (AutBehav). We examined which specific behaviors distinguished the behavioral phenotype of DS + ASD from other aberrant behavior disorders in DS, by determining the relative contribution of ABC and AutBehav subscales and items to the diagnosis of ASD. A total of 127 subjects (aged 2-24 years; mean age: 8.4 years; approximately 70% male), comprising: a cohort of 64 children and adolescents with DS and co-morbid ASD (DS + ASD), 19 with DS and stereotypic movement disorder (DS + SMD), 18 with DS and disruptive behaviors (DS + DB), and 26 with DS and no co-morbid behavior disorders (DS + none) were examined using the aforementioned measures of aberrant behavior. We found that subjects with DS + ASD showed the most severe aberrant behavior, especially stereotypy compared to DS + none and lethargy/social withdrawal and relating problems compared to DS + SMD. Specifically, relatively simple stereotypic behavior differentiated DS + ASD from DS + DB, whereas odd/bizarre stereotypic and anxious behavior characterized DS + ASD relative to DS + SMD and DS + none. Additionally, in a subset of subjects with DS + ASD and anxiety, social withdrawal was particularly pronounced. Overall, our findings indicate that a diagnosis of DS + ASD represents a distinctive set of aberrant behaviors marked by characteristic odd/bizarre stereotypic behavior, anxiety, and social withdrawal.
Published Date: 
January, 2007

Kennedy Krieger Institute Announces Retirement of President and CEO

Dr. Gary W. GoldsteinThe Institute’s board of directors is conducting a national search and is expected to name a new CEO in the coming months.
Learn more.

Appointments & Referrals



Read inspiring stories, news and updates about the Institute's patient care, research, special education, professional training, and community programs.


Resource Finder


A free resource that provides access to information and support for individuals and families living with developmental disabilities.