Based on the reported theta ERO deficits among alcohol dependent and high-risk subjects with limited alcohol exposure, it has been hypothesized that these oscillatory deficient responses antecede the development of alcoholism and may serve as an effective endophenotype to the condition [Rangaswamy and Porjesz, 2008]. Thus, the four SNPs identified above as potential genetic determinants of theta EROs were further examined for their association to alcohol dependence in both the GWAS sample and the family-based replication data (Table IV). For the GWAS samples, the association analysis for affected status (with principal components, age and sex as covariates in additive genetic effects model) produced one significant result among the four SNPs – rs7916403 from serotonin receptor gene HTR7 (P = 8.0 × 10−3). The alleles of rs7916403 are T and G, with T having a minor allele frequency of 0.49 (see Table III). The odds ratio (OR) for the G allele is 1.24 [95% CI: 1.06 – 1.45], with an increased OR of 1.32 [95% CI: 1.02 – 1.71] when tested for a full recessive model (P = 0.036), suggesting a
