Table 1 provides an overview of the 12 published AD GWAS. The first GWAS of AD was published in 2009 in a sample of German men, including 476 cases and 1,358 controls (Treutlein et al., 2009). The discovery phase involved over 500,000 SNPs and was followed by a replication analysis of 139 SNPs in 1,024 AD cases and 996 controls. Although no associations were genome-wide significant (GWS) in the discovery sample, two SNPs that mapped to the PECR gene were GWS in a meta-analysis of the discovery and replication samples. Overall, 15 top-ranked SNPs located in or near several genes (CAST, ERAP1, PPP2R2B, ESR1, CCD41, ADH1C, GATA4, and CDH13) were GWS in a meta-analysis of the discovery and replication samples.
