While both the T2D marker rs2334499 and the breast cancer marker rs3817198 fall within 350 kb of imprinted genes, the region harboring both rs2334499 and rs3817198 has not been reported to be imprinted (Figure 2)19 The T2D associated marker rs2334499 resides within the first intron of HCCA2, a gene spanning 300 kb including several other genes (Figure 2) including KRTAP5-1 to -5 genes, DUSP8 and CTSD20. To determine if genes in this region showed signs of imprinting we performed allele specific expression analysis of the HCCA2, CTSD and DUSP8 genes (Figure 2) as well as three genes known to be imprinted in the 11p15.5 region (IGF2, KCNQ1 and KCNQ1OT1, in RNA isolated from peripheral blood and adipose. While allele specific expression of IGF2, KCNQ1 and KCNQ1OT1 was confirmed in this dataset clear biallelic expression was seen for HCCA2 and DUSP8. However, excess paternal expression could not be ruled out for CTSD (Supplementary Information, Supplementary Table 6).
