Among the 10 SNPs that we have genotyped, 1 SNP (rs991246, located upstream of the CRHR1 gene) had a very low minor allele frequency (MAF) 0.0024, and was omitted from analysis. Pair-wise estimates of linkage disequilibrium (Abecasis and Cookson, 2000) between the remaining 9 CRHR1 SNPs in this study are shown by Haploview in Fig. 1. The SNPs showing the strongest association with the visual P3 amplitude and with alcohol dependence phenotypes (Table 2) are in strong linkage disequilibrium (LD) with one another (Fig. 1).
