Tauopathies - a new class of neurodegenerative diseases

Recently it was shown by several research groups that mutations in the gene encoding for the tau protein associated with microtubuli on chromosome 17 caused a distinct form of dementia named frontotemporal dementia and parkin sonism (FTDP-17). This disease includes familial asymmetrical frontal and, in the further course, frontotemporal dementia, parkinsonism,which is often initially sensitive to levodopa, signs of upper motor neuron degeneration, and,less commonly, amyotrophy. Tau is an intracellular protein of the cytos keleton, which is responsible for the arrangement and stabilization of micr otubuli. The discovery of mutations in the tau gene causing a distinct neur odegenerative disease in humans has firmly established the importance of th e tau gene for neurodegenerative processes, not only in tauopathies but als o in other degenerative disorders with tau pathology, such as corticobasal degeneration, supranuclear progressive paralysis, amyotropic lateral sclero sis, parkinsonism-dementia complex of Guam, and Alzheimer's disease. Our ex perience with patients suffering from PTDP-17 shows that its phenotype vari es more than was described in the first consensus conferences. In the futur e, it will be important to designate the diagnostic gold standard not by cl inical description, but etiologic classification.