• autism;
  • behavioural phenotypes;
  • cognitive level;
  • Cornelia de Lange Syndrome;
  • intellectual disability;
  • self-injury


Background  Few studies have investigated functional and behavioural variables of Cornelia de Lange Syndrome (CdLS) in a large sample of individuals. The aim of this study is to provide greater insight into the clinical, behavioural and cognitive characteristics that are associated with CdLS.

Methods  In total, 56 individuals with CdLS participated in the study. During hospitalization, their mothers received a number of questionnaires to complete. The behavioural phenotype was investigated using the following scales: Developmental Behaviour Scale Primary Carer Version; Autism Behaviour Checklist; Childhood Autism Rating Scale.

Results  Our participants demonstrated some behavioural characteristics that are frequently associated with CdLS (hyperactivity, attention disorder, anxiety, compulsive disorders, self-injurious behaviour and autistic-like features). Our findings demonstrate the variability of behavioural characteristics in CdLS in addition to highlighting the contribution of some variables to both the CdLS behavioural profile and the developmental trajectory of the behavioural pattern.

Conclusions  The behavioural characteristics identified in our sample were correlated with some clinical and functional aspects (chronological age, cognitive level and clinical phenotype). The variability of the behavioural profile in CdLS reflected the wide variability in cognitive and adaptive functioning across individuals and led us to conclude that there may be multiple behavioural phenotypes associated with the syndrome. Further comparative studies between CdLS and individuals with intellectual disability or other genetic syndromes may help to provide further understanding of the behavioural phenotype of CdLS.