Genetic studies have identified several genes associated with monogenic FTD: in 1998, mutations in the microtubule-associated protein tau (MAPT) gene on chromosome 17 were identified in families with FTD and parkinsonism (Hutton et al., 1998; Poorkaj et al., 1998; Spillantini et al., 1998). Here, MAPT is linked to frontotemporal dementia.