Although no marker met genome-wide significance criteria, this is not entirely unexpected given evidence that substantially larger sample sizes may be necessary to reliably identify loci of small effect in complex traits (Bacanu and Kendler, 2017; Sullivan et al., 2017). Suggestive loci localize to several genes of interest. For example, SLC6A11 is a GABA transporter preferentially expressed in brain (Fagerberg et al., 2014); variation in this gene has been associated with intellectual and behavioral aberrations (Dikow et al., 2014) and resistance to epilepsy pharmacotherapy (Kim et al., 2011). Given the role of the GABAergic system in alcohol response and sensitization (Camarini and Pautassi, 2016; Koob, 2013), the biological plausibility of SLC6A11 is compelling. While other GABAergic genes involved in alcohol-relevant processes had suggestive p-values (e.g., GABARAP, p=0.003; GABRB3, p=0.001), these did not survive a multiple testing correction. Genes implicated in recent large GWAS of alcohol-related outcomes (Clarke et al., 2017; Jorgenson et al., 2017; Sanchez-Roige et al., 2017; Schumann et al., 2016) were also not supported. Indeed, no locus implicated by lead SNPs or gene-based analyses has been previously associated
