Review: The genetics of Alzheimer's disease; putting flesh on the bones

For two decades the search for genes involved in Alzheimer's disease brought little reward; it was not until the advent of genome-wide association studies (GWAS) that genetic associations started to be revealed. Since 2009 increasingly large GWAS have revealed 20 loci, which in itself is a substantial increase in our understanding, but perhaps the more important feature is that these studies have highlighted novel pathways that are potentially involved in the disease process. This commentary assembles our latest knowledge while acknowledging that the casual functional variants, and undoubtedly, other genes are still yet to be discovered. This is the challenge that remains and the promise of next-generation sequencing is anticipated as there are a number of large initiatives which themselves should start to yield information before long.