Based on the association in AAs of one of the SNPs in the CLOCK gene with membership in Group 4, we examined the linkage disequilibrium (LD) structure of the 9 genotyped CLOCK SNPs in the 1,478 AAs for which genotypes were available. These SNPs spanned 71,151 bp on chromosome 4. Figure 1 shows the LD relationships of the nine SNPs analyzed using Haploview 4.1 software. Rs119398115, the SNP that was significantly associated with membership in Group 4, had very high D′ (normalized LD) with respect to two of the nominally significant SNPs from the CLOCK gene: rs6850524 and rs13116194, which were also in high LD with one another.
