Novel L284R MAPT mutation in a family with an autosomal dominant progressive supranuclear palsy syndrome

Abstract

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.

Fig. 1

Family tree of DRC292.

Fig. 2

Secondary structure predictions using PSIPRED (http://bioinf.cs.ucl.ac.uk/psipred/). The non-conservative arginine substitution causes a reduction in the predicted α-helical content (H) of the region containing the residue.