Interestingly, four of these SNPs that exhibited maternal and fetal effects in opposing directions (three of which were confirmed using the conditional analysis in Horikoshi et al.6) are known type 2 diabetes loci (ADCY5, HHEX/IDE, CDKAL1 and ANK1), consistent with what is known regarding the underlying biology at these loci.19 This evidence concerns the gene HHEX and type 2 diabetes mellitus.