Twenty years of Alzheimer's disease-causing mutations.

In this study, we review our finding of APP mutations in Alzheimer's disease in 1990-1991 with the benefit of 20 years' perspective. We discuss the historical context in which we made the finding, its immediate and continuing effects on research activity and our hopes for successful clinical testing of the hypothesis. We also briefly discuss the effects finding APP mutations has had on our own careers and those of our colleagues from 1991.