The linkage disequilibrium (LD) pattern and haplotype block delineation were determined by applying Haploview 4.0 (http://www.broad.mit.edu/mpg/haploview) (Barrett et al., 2005). Blocks were defined using the confidence interval method described by Gabriel et al. (Gabriel et al., 2002). Pairwise LD measures (r2 and D′) were calculated in the 366 healthy controls of the GWAS sample and in 284 controls of the African-American sample for the eight most associated SNPs on chr12.21.31 (see fig. 2). German controls were also compared to the HapMap CEU population (CEPH sample consisting of Utah residents with ancestry from northern and western Europe, N=60, http://www.hapmap.org) (Frazer et al., 2007). No deviation in LD could be observed in this comparison (data not shown).
