There are three known SNPs in the 4E3 enhancer region (NCBI dbSNP Build 130). The genotype and allele frequencies of two SNPs are shown in Table 3; frequencies for the third SNP are unavailable. In transient transfections, we tested four different haplotypes of 4E3 cloned upstream of the ADH4 promoter. We normalized the activity of all haplotypes to the most common haplotype in all populations: rs7678936 G, rs7678890 T, and rs11401494 del, which we denote as haplotype 1. The activity of haplotype 2 (T, T, del) was only 60% that of the haplotype 1. Haplotype 3 (G, G, del) displayed a similar decrease in activity. Insertion of A at position −13,058 (Haplotype 4: G, T, A) had a very small effect (0.9-fold change relative to the haplotype 1, p =0.02; Figure 7).
