Alzheimer's disease.

Abstract

Alzheimer's disease is a chronic illness with long preclinical and prodromal phases (20 years) and an average clinical duration of 8-10 years. The disease has an estimated prevalence of 10-30% in the population >65 years of age with an incidence of 1-3%. Most patients with Alzheimer's disease (>95%) have the sporadic form, which is characterized by a late onset (80-90 years of age), and is the consequence of the failure to clear the amyloid-β (Aβ) peptide from the interstices of the brain. A large number of genetic risk factors for sporadic disease have been identified. A small proportion of patients (<1%) have inherited mutations in genes that affect processing of Aβ and develop the disease..