Prior genome-wide association studies (GWAS) of AD and alcohol-related phenotypes in European samples detected novel signals in the PECR (Treutlein et al., 2009), AUTS2 (Schumann et al., 2011) and uncharacterized c15orf53 (Wang et al., 2013) genes. None of these novel signals were replicated. Two independent signals were detected and replicated around the long-standing candidate gene ADH1B (Frank et al., 2012; Gelernter et al., 2014). Three studies of Asian subjects identified signals at ALDH2 (Baik et al., 2011; Quillen et al., 2014) and the ADH1B functional variant H47R (rs1229984) (Park et al., 2013), likely due to the frequencies of functional ADH and ALDH alleles in Asian populations.
