A Case Study on a Novel MAPT Mutation Causing FTLD

Frontotemporal dementia (FTD) is a type of dementia that affects the frontal and temporal lobes of the brain as well as other subcortical structures. Although sporadic onset of these dementias is not known, there are several genes that are implicated to have a hereditary FTD. The three most common genes are progranulin (GRN), C9orf72, and the microtubule associated protein tau (MAPT). The MAPT gene, which is found on chromosome 17, encodes the tau protein. This protein, which is mostly associated with neurons but can also be in other cells of the brain, has important functions within these cells that are essential for the cells to stay alive. When mutations affect the tau protein, proper functioning does not occur, and the cell will eventually die. This cell death is responsible for the degeneration seen in this kind (and other kinds) of dementia. In this study, we reviewed a case with a novel mutation in the MAPT gene. Sections of the brain are reviewed to describe the pathologic lesions to associate FTD with this novel mutation.