A subset of the most genetically informative families was selected for a family-based genome-wide association analysis (GWAS). This sample has been described in detail elsewhere (Kang et al., 2013; Wang et al., 2013) but salient characteristics are presented here. Families were prioritized based on the number of family members with: (1) available DNA who were also alcohol dependent, (2) available DNA who also had electrophysiology data, and (3) available DNA, regardless of other phenotypes. To reduce heterogeneity, only families consisting primarily of self-reported European American ethnicity were included in the sample. The final sample was comprised of 118 large European American families consisting of 2,322 individuals with available DNA.
