Late‐onset presentation and phenotypic heterogeneity of the rare R377W PSEN1 mutation

Here, we describe an atypical presentation of the rare R377W PSEN1 mutation, emphasizing the unusual late age of onset and the mixed frontotemporal and parieto‐hippocampal dysfunction. In order to do so, beside a detailed clinical characterization, we provide a description of the family tree, conventional imaging findings and, for the first time, amyloid‐PET. Extensive genetic screening is advisable also for late‐onset presentations of Alzheimer’s disease, especially in the presence of a positive family history or atypical clinical features.