Data from the Collaborative Study on the Genetics of Alcoholism (COGA) suggest that chromosome 2p14–2q14.3 may contain a gene (or genes) with pleiotropic effects on alcohol dependence and related psychiatric conditions. Initially, linkage was detected near the marker D2S379 (LOD = 3.0) with an alcohol dependence (AD) phenotype, defined as meeting diagnostic criteria according to the DSM-IIIR and Feighner classification systems [Foroud et al., 2000]. Subsequently, linkages to the same region were identified with the phenotypes of suicide attempts (SUI) [Hesselbrock et al., 2004] and conduct disorder (CD) [Dick et al., 2003]. These findings are robust, with replication reported in multiple independent samples: Suicide attempts were linked to this same region of chromosome 2 in pedigrees affected with early-onset major depression [Zubenko et al., 2004] and with bipolar disorder [Willour et al., 2007]. Linkage of conduct disorder to this region was replicated in the Irish Affected Sib Pair Study for Alcohol Dependence [Kendler et al., 2006a]. Further analysis of a subset of the COGA pedigrees on whom genome-wide SNP linkage data were produced for the Genetic Analysis Workshop 14 (GAW14)
