The Cognitive Profile and Autistic Characteristics Associated with Sotos Syndrome

The purpose of this thesis was to advance understanding of the cognitive and behavioural profiles associated with Sotos syndrome. Specifically, the aim of this thesis was to establish the cognitive profile and whether autistic features are associated with Sotos syndrome. Initially, a systematic review of all published literature providing data on cognition and behaviour in Sotos syndrome was conducted. In general, research investigating cognition and behaviour in Sotos syndrome has been sporadic and much of the existing literature is based on small samples. The findings from the systematic review were used to inform the design of the research presented in the subsequent chapters. The studies reported within this thesis have used the largest samples to date to investigate cognition and behaviour in individuals with Sotos syndrome. Specifically, the findings demonstrate that Sotos syndrome is associated with a high prevalence of autistic features, as well as a clear and consistent cognitive profile. In particular, the Sotos syndrome cognitive profile is characterised by relative strength in verbal ability and visuospatial memory and relative weakness in non-verbal reasoning ability and quantitative reasoning. Furthermore, greater severity of autistic features is associated with lower intellectual ability for individuals with Sotos syndrome. Communicative difficulties are common in both adults and children with Sotos syndrome and individuals display difficulty with both structural and pragmatic aspects of language. Overall, the findings reported within this thesis advance understanding of the cognitive and behavioural phenotype of Sotos syndrome and have important implications for considering the syndrome-specific needs of these individuals.