International Meeting for Autism Research (London, May 15-17, 2008): Social behavior and autism traits in a sex chromosomal disorder: Klinefelter (47XXY) syndrome

Social behavior and autism traits in a sex chromosomal disorder: Klinefelter (47XXY) syndrome

Thursday, May 15, 2008
Champagne Terrace/Bordeaux (Novotel London West)
10:30 AM
S. Van Rijn , Department of Clinical Child and Adolescent Studies, Leiden University, Leiden, Netherlands
H. Swaab , Department of Clinical Child and Adolescent Studies, Leiden University, Leiden, Netherlands
A. Aleman , BCN NeuroImaging Center, University of Groningen, Groningen, Netherlands
R. S. Kahn , Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, Netherlands
Background: Klinefelter syndrome (47,XXY)  is a sex chromosomal disorder that affects approximately 1 in 700 boys. Although there is a general impression that boys or men with Klinefelter syndrome often struggle with social situations, knowledge of the social behavioral phenotype of Klinefelter syndrome is limited. Difficulties in coping with the social environment may be indicative of an increased vulnerability for autistic traits. However, to our knowledge, there has been no study of autism-like features in a large sample of individuals with Klinefelter syndrome.
Objectives: The aim of this study was to improve our understanding of the social behavioral phenotype in Klinefelter syndrome by assessing social abilities and autism traits.
Methods: 31 XXY men and 24 non-clinical controls were included in the study. We used the Scale for Interpersonal Behavior, a quantitative measure of the degree to which individuals participate in specific social interactions and at the same time the degree to which they are distressed during these social situations. Importantly, this measure allows a quantification of social capacities that are normally distributed in the general population. We also included the Autism Spectrum Questionnaire, a dimensional measure of autistic personality traits which are distributed along a continuum in the general population.
Results: XXY men reported increased levels of distress during social interactions and less engagement in those aspects of social behavior that deal with display of negative emotions. Interestingly, we observed considerably increased levels of autistic traits across all dimensions of the autism phenotype in XXY men: social skills, communication, imagination, attention to detail and attention switching.
Conclusions: These findings call for a clinical investigation of vulnerability to autism in Klinefelter syndrome. Although our findings require replication, Klinefelter syndrome might serve as a model for studying a role of the X chromosome in social behavioral dysfunction and autism-like behavior.