Novel L284R MAPT Mutation in a Family with an Autosomal Dominant Progressive Supranuclear Palsy Syndrome

Background: MAPT mutations are associated with disorders within the frontotemporal lobar degeneration spectrum. The usual presenting syndrome is behavioural variant frontotemporal dementia, although some patients present with parkinsonism. In a number of these cases the dominant clinical features have been consistent with a progressive supranuclear palsy (PSP) syndrome. Objective: To describe a family with an autosomal dominant PSP syndrome with a novel L284R mutation in the MAPT gene. Methods: A retrospective case review and genetic analysis of the MAPT gene. A literature review of PSP syndromes associated with mutations in the MAPT gene. Results: Multiple members of family DRC292 across different generations had a PSP syndrome with 1 member of the family being found to have a novel L284R mutation in the MAPT gene. Behavioural features were also prominent in most cases. A PSP syndrome is only a rare finding associated with MAPT mutations and many of these cases have atypical clinical features. Conclusion: Although rare, MAPT mutations should be considered when there is an autosomal dominant family history of a PSP syndrome, particularly of young onset and with prominent behavioural features.