Genome-wide association studies-derived susceptibility loci in type 2 diabetes: confirmation in a Chinese population.

PURPOSE: Several novel genetic variants for type 2 diabetes mellitus (T2DM) have been identified through genome-wide association studies (GWAS). A case-controll study was performed to investigate the association of five new European or South Asian GWAS-derived susceptibility loci with T2DM in a Chinese population.

METHODS: Five single nucleotide polymorphisms (SNPs) were genotyped: rs3923113 near GRB14, rs16861329 in ST6GAL1, rs1802295 in VPS26A, rs7178572 in HMG20A, and rs231362 near KCNQ1, by high-resolution melting (HRM) of small amplicons. The association between T2DM and related quantitative traits in a total of 900 Chinese individuals, including 498 type 2 diabetic patients and 402 ethnically matched control subjects, were examined.

RESULTS: After adjusting for age and gender, rs1802295 (OR 5.724, P=0.03) and rs231362 (OR=5.683, P=0.016) were found to be associated with T2DM. Triglyceride levels were higher in TT and CT carriers for rs16861329 (1.05 (0.8-1.34) mmol/l) than in CC carriers (0.91 (0.73-1.23) mmol/l) with P=0.008 and that high-density lipoprotein cholesterol (HDL-C) was lower in TT and CT carriers (1.17 (1.02-1.33) mmol/l) than in CC carriers (1.21 (1.05-1.41) mmol/l), with P=0.034. For rs3923113, the HDL-C levels were lower in the GG carriers (1.08 (0.90-1.18) mmol/l) than in the GT+TT carriers (1.21 (1.04-1.38) mmol/l), with P=0.018. Ours is the first report of this association.

CONCLUSION: rs231362-KCNQ1 and rs1802295-VPS26A are associated with T2DM in the Chinese population. The remaining three SNPs are associated with other aspects of lipid metabolism.