Abstract
Alois Alzheimer (1864–1915) was born in Markbreit, Bavaria, the son of a government officer. He studied medicine at the Universities of Wurzberg, Tubingen and Berlin, obtaining his MD from the University of Wurzberg in 1887. He became a pathologist of the nervous system, professor at a Breslau psychiatric institute and editor of a psychiatric journal and of a six-volume encyclopaedia of brain pathology. His description of senile plaques of the brain deservedly led to his eponymous immortality. We now recognize that the hallmarks of this presenile dementia are extracellular plaques and intracellular neurofibrillary tangles. The senile plaque contains β-amyloid, a hydrophobic peptide of 39–43 amino acids. Mutations in the amyloid precursor protein are now recognized to be on chromosome 21 in the familial form of the disease. One of the missense genes, S182, is now recognized in Italian and Japanese families with early-onset disease. α-Secretase-cleaved amyloid precursor protein levels are low, and carriers of the presymptomatic mutation show intermediate levels.