Polymorphisms in the Promoter of the Human APP Gene

Abstract

THE NEUROTOXIC and amyloidogenic peptide Aβ is generated by proteolytic cleavage of the amyloid precursor protein (APP).¹ Genetic and functional studies have assigned a pivotal role for increased Aβ production in the neuropathologic characteristics of Alzheimer disease (AD). Several factors account for the increased secretion of Aβ and the accelerated aggregation of this peptide in AD. These include missense mutations in the APP gene and in the genes encoding presenilin-1 and presenilin-2, which increase the proteolytic conversion of APP into the fibrillogenic Aβ42 peptide and lead to early-onset AD.^2- 4 A coding change in a third locus, the apolipoprotein-E (APOE) ϵ4 variant, acts to increase Aβ aggregation and is a significant risk factor for late-onset AD.^5,6