Tau mutations in frontotemporal dementia.

Genetic analysis has determined that a series of disorders related clinically and pathologically to frontotemporal dementia (FTD) are etiologically related. The relationship between these disorders was initially established based on linkage analysis and has been solidified by the identification of mutations in the tau gene in many families. Mutations affecting the expression or structure of the microtubule binding domain of the tau gene have been found in many large families with chromosome 17q21-22-linked disease. These mutations only account for a small fraction of cases of FTD that are either sporadic or that contain only a few affected relatives.