In our present study, the findings support the individual associations of CDKN2A/2B (rs10811661), SLC30A8 (rs13266634 and rs2466293), CDKAL1 (rs7756992) and KCNQ1 (rs2237892) with not only T2DM but also IGR in a case-control study. This evidence concerns the gene KCNQ1 and type 2 diabetes mellitus.