Exploring the prevalence and phenomenology of repetitive behaviours and abnormal sensory processing in children with Williams syndrome Corresponding Author: RUNNING HEAD: Sensory difficulties and repetitive behaviours in WS

Background: A small amount of research with individuals who have Williams Syndrome (WS) suggests that children with the condition may be vulnerable to sensory processing abnormalities and present with repetitive and restricted behaviours. Methods: Parents of twenty-one children with WS aged 6-15 years completed a semistructured interview designed to elicit the form, frequency, impact and developmental course of a range of sensory processing abnormalities and repetitive behaviours. Results: Findings indicate that sensory processing difficulties are predominantly characterised by hypersensitivities, particularly in relation to vestibular, auditory, gustatory and proprioceptive functioning. Parents also reported the presence of a range of restricted and repetitive behaviours, which were often associated with their child’s sensory symptoms. Conclusions: This study makes a significant contribution to our understanding of sensory functioning and repetitive behaviours in WS. It also highlights the need for a multidisciplinary assessment of the difficulties experienced by children with the disorder.