Previously, a set of 262 genetically informative, multiplex alcohol dependence pedigrees, each with at least three first degree relatives who met lifetime criteria for both DSM-IIIR alcohol dependence (American Psychiatric Association,1987) and Feighner definite alcoholism (Feighner et al., 1972) were selected from the larger COGA sample and used in linkage and family based association studies (Edenberg et al., 2004; Edenberg and Foroud, 2006; Foroud et al., 2000; Reich et al., 1998); 59 additional trios were also genotyped. After reviewing the results from the primary analysis of DSM-IV alcohol dependence, the 199 SNPs with the smallest p values for association (p ≤ 2.1 × 10−4) were selected for genotyping in this family-based sample. Genotypes were completed on 180 of these SNPs; the others did not design into assays or did not provide useable data.
