We also investigated the 35 ISC SNPs with associations < 5×10−8 and all were located from chr6:31.58–32.77 mb in the MHC region (Purcell et al., 2009). These SNPs map to 10 genes (Table 3b), five of which had not previously been the subject of a candidate gene study. Four genes had been studied 1–5 times and one extensively (NOTCH4). The strong caveat for Table 3b is the extensive linkage disequilibrium in the MHC region (Figure S1); these genome-wide significant SNPs could reflect one or a few risk variants which may or may not be a candidate gene.
