GRN and behavioral variant of frontotemporal dementia: This suggests that memory impairment differs between bvFTD patients depending on the underlying mutation and thus atrophy pattern, with MAPT mutation carriers demonstrating a “pure” memory impairment resulting in lower performance on both immediate and delayed recall, whereas the immediate recall impairment in C9orf72 and GRN mutation carriers are potentially a consequence of prefrontal and thus dysexecutive impairment, with relatively spared delayed recall performance.