Our study was therefore designed to test our hypothesis that GABRA2, childhood trauma and their interaction would contribute to vulnerability to substance dependence. To this end, the study sample included African American men recruited from a Veterans’ Affairs substance abuse treatment program, the majority of whom had comorbid alcohol, heroin and cocaine dependency, and African American male controls. The sample had been exposed to considerable childhood trauma. In investigating GABRA2 variation we focused both on the distal GABRA2 haplotype block that has previously been associated with substance dependence (12–21)and on a novel intron 2 SNP, rs11503014, that is not located in any haplotype block and is potentially implicated in exon splicing.
