Our recent studies of plasma, fibroblasts, transfected cells and transgenic mice show that a
fundamental effect of the mutations linked to familial Alzheimer's disease (FAD) is to
increase the extracellular concentration of Aβ42. This effect of the FAD-linked mutations is
likely to be directly related to the pathogenesis of Alzheimer's disease (AD) because Aβ42 is
deposited early and selectively in the senile plaques that are an invariant feature of all forms
of AD. Thus our results provide strong evidence that the FAD-linked mutations all cause AD …