Sleep in rare genetic syndromes

In this thesis, the profiles and developmental trajectories of poor sleep were explored in children with Angelman syndrome (AS) and Smith-Magenis syndrome (SMS) across a series of studies. These syndromes were found to be at greater risk of poorly-defined ‘general’ sleep difficulties than four and five other genetic syndromes respectively, in a meta-analysis of 212 studies. A range of potential aetiological and/or maintaining factors for poor sleep in these syndromes were considered and explored through the development and evaluation of novel methodological approaches. These approaches were designed to be suitable for assessing sleep and known aspects of the behavioural and physical characteristics of these two exemplar syndromes, with broader implications for sleep assessment in intellectual disability. Using videosomnography and radio frequency identification assessments of parent-child proximity, potential indicators of pain and evidence for potentially rewarding parent-child interactions were identified for both groups. In addition, this thesis presents the first objective longitudinal studies of poor sleep in both groups, employing actigraphy and questionnaire analysis of poor sleep over three years in comparison with chronologically age-matched typically developing (TD) peers. In both groups, actigraphy-defined sleep parameters were found to be stable in comparison to TD peers, suggesting divergent trajectories for poor sleep and priorities for intervention. This thesis contributes significantly to understanding of the profile and aetiology of poor sleep in individuals with AS and SMS and the development of robust methodological approaches available to assess these in individuals with intellectual disability more broadly