Interventions in Mowat Wilson Syndrome: A Scoping Review

Mowat-Wilson syndrome (MWS) is a rare autosomal dominant condition caused by a heterozygous mutation or deletion of the ZEB2 gene. The syndrome occurs in both sexes but is potentially more frequently diagnosed in males. The number of new cases is estimated to be 1 in 50,000-70,000 born children. MWS is characterised by a distinctive facial appearance in association with intellectual disability (ID) and a range of other features including epilepsy, and Hirschsprung disease, microcephaly, agenesis of the corpus callosum and congenital heart defects. Epilepsy is considered a main manifestation of the syndrome and affects approximately 80% of individuals with MWS. Developmental milestones are delayed, and speech is limited to a few words. Behavioural and emotional difficulties have also been reported. This scoping review aimed to identify the existing literature on interventions targeting individuals with MWS and identify gaps in order to guide future research. A search yielded six studies that encompassed a total of 34 participants, both males and females, with an age span of three months to 45-years-old. The focus of the studies included was medical treatment of epilepsy and surgery for Hirschsprung’s disease, with mixed results. One study reported improvement of behavioural problems using psychopharmacological management. Four of the six selected studies had a case-report design. The quality appraisal revealed heterogeneity in the level of details reported and the overall quality of the studies. Hence, the generalisability of the results should be interpreted with caution. This scoping review shows that studies of interventions targeting symptoms in individuals with MWS are still very scarce. As MWS is a rare disease, it is difficult to conduct randomized controlled trials at a group level. One viable alternative could be single case experimental design studies (SCED) which can reveal experimental effects with just one case. Aggregated findings from such designs can also facilitate recommendations of evidence-based interventions for individuals with rare disorders. The studies included mainly examined physical health, but other factors also may improve an individual’s well-being. Intervention studies in other research areas, for instance, communication, motor functioning, learning and behaviour and participation in daily life activities are therefore called for. It would also be of interest to further examine how functioning in different areas correlates with quality of life for individuals with MWS.