Welcome to the complex disease world

The recent explosion in our understanding of Alzheimer’s disease (AD) at both the molecular and biochemical levels is due, in large part, to the successful utilization of genetic and genomic analyses over the past two decades. Initial positional cloning efforts of the 80s and 90s led to the identification of three genes, amyloid precursor protein (APP) and presenilins 1 and 2 (PSEN1 and PSEN2), that can harbor mutations leading to the rare,...