Frontotemporal dementia genetics.

Frontotemporal dementia (FTD) is the most common syndrome in which the focus of neurodegeneration is the frontal lobes. FTD is frequently familial. It is also often due to a susceptibility locus on chromosome 17q21-22. Some 17q21-22-linked families have mutations in the tau gene and most have microscopically visible aggregates of hyperphosphorylated tau. Demonstrating that mutations in tau can produce neurodegeneration will necessitate a reassessment of the role of tau in the pathogenesis of the many diseases in which tau biology is disrupted.