Background: Cornelia de Lange syndrome is associated with abnormalities on chromosomes 5, 10 and X.
Aims: To delineate the behavioural phenotype of Cornelia de Lange syndrome with specific reference to autistic-spectrum disorder.
Method: A total of 54 individuals with Cornelia de Lange syndrome (mean age 13.88 years; s.d.=8.58) and 46 comparable individuals with intellectual disability (mean age 13.74 years; s.d.=7.99) were assessed on measures of autistic-spectrum disorder, and adaptive, compulsive and disordered behaviour.
Results: There was no difference between the groups in global behaviour disorder. Severe autism was significantly more prevalent in the syndrome group (32.1%) than the comparison group (7.1%). In addition, the syndrome group also evidenced significantly higher levels of compulsive behaviour.
Conclusions: These data suggest that autistic-spectrum disorder is part of the behavioural phenotype of Cornelia de Lange syndrome and that compulsive behaviours are evident. Future research should investigate this behavioural phenotype using contemporary diagnostic algorithms for autism with detailed examination of the phenomenology of compulsive behaviours.