[Genetics of Alzheimer's disease].

This review reports epidemiological data and biological mechanisms about the Apolipoprotein E gene allele epsilon 4 that is a major risk factor for Alzheimer's disease (AD). The second part describes the three genes, amyloid precusor protein (APP), presenilin 1 (PS1) and presenilin 2 (PS2) genes, which when mutated cause early-onset autosomal dominant AD. Mutations on each of these genes have as a common consequence elevated levels of A beta (42,3).