We describe a patient with a clinical diagnosis of frontotemporal dementia (behavioral variant) without Parkinsonsim and a novel heterozygous missense mutation (GGA>AGA, c.163g>a, BN000503.1) causing a substitution of arginine for glycine at position 55 (G55R) in the alternatively spliced exon 2 of the MAPT gene (Figure 1). Here, MAPT is linked to frontotemporal dementia.