C9orf72 and frontotemporal dementia: For example, symptomatic carriers of mutations in the microtubule-associated protein tau gene (MAPT) tend to show more severe disinhibition and compulsive behavior; whereas, those with mutations in the chromosome 9 open reading frame 72 (C9orf72) or granulin gene (GRN) have increased frequencies of delusions and hallucinations.17, –19 Magnetic resonance imaging (MRI) findings suggest that the progression of NPS in patients with FTD and other dementia subtypes may be associated with structural changes, such as gray matter (GM) atrophy20,21 or white matter signal abnormalities (WMSA).22, –24