Beschreibung:
<jats:p>Alzheimer's disease (AD) is the most common cause of dementia in the elderly, whereas frontotemporal lobar degeneration (FTLD) is the most frequent neurodegenerative disorder with a pre-senile onset. The two major neuropathological hallmarks of AD are extracellular amyloid beta plaques and intracellular neurofibrillary tangles. In FTLD the deposition of tau has been observed in a number of cases, but in several brains there is no deposition of tau but instead a positivity for ubiquitin. In some families these diseases are inherited in an autosomal dominant fashion. Genes responsible for familial AD include the amyloid precursor protein (<jats:italic>APP</jats:italic>), presenilin 1 (<jats:italic>PS1</jats:italic>) and presenilin 2 (<jats:italic>PS2</jats:italic>), whereas the main genes responsible for familial FTLD are microtubule-associated protein tau gene (<jats:italic>MAPT</jats:italic>) and progranulin (<jats:italic>GRN</jats:italic>). Concerning sporadic AD, it is known that the presence of the ε4 allele of the apolipoprotein E gene is a susceptibility factor. A number of additional genetic factors contribute to susceptibility for AD and FTLD.</jats:p>