GRN and frontotemporal dementia: Frontotemporal dementia (FTD) accounts for 20% of early-onset dementia cases, characterized by core features of behavioral abnormalities and language impairment (Author Anonymous, 1994), The pathological mechanisms are frequently associated with mutations in MAPT, GRN, or C9orf72 genes, with other rare pathogenic genes identified in less than 5% of cases (Greaves and Rohrer, 2019).