Association between Gene Polymorphisms of Seven Newly Identified Loci and Type 2 Diabetes and the Correlate Quantitative Traits in Chinese Dong Populations

BACKGROUND There are much heterogeneity in the genetic variation of type 2 diabetes (T2D). The purpose of this study was to investigate the association of seven novel genetic loci identified in a recent genome-wide association studies (GWAS) with T2D in Chinese Dong populations. METHODS A case-controlled study was performed in individuals of Chinese Dong nationality. The genotypes of PARD3B (rs849230), LOC729993 (rs149228), EPHA4 (rs16862811), HNT (rs3099797), PTPRD (rs17584499 and rs649891), TOMM7 (rs2240727) genes were determined using Multiplex PCR-SNaPshot. The independent association between each polymorphism and T2D was assessed using unconditional binary logistic regression analysis (BLR). RESULTS A total of 136 cases of T2D and 136 control subjects were enrolled in the study. The polymorphism of rs2240727 in TOMM7 gene was associated with T2D (odds ratio (OR) = 1.65, per copy of the risk T allele, P = 0.004). In addition, CT and TT were risk genotypes for T2D (OR (95% CIs):2.64 (1.28-5.45) and 3.42 (1.58-7.41) respectively). After correcting for multiple testing, the above results remained significant (all P < 0.05). After adjusting for the confounders of age, gender, and BMI, the association between T2D and rs2240727 remained significant (P < 0.01). There were significantly statistical difference in levels of fasting plasm glucose(FPG) among genotypes of rs2240727 in controls and patients, the levels of FPG were significantly higher in CT and TT genotypes than in CC genotype in both groups (all P < 0.05). CONCLUSIONS The rs2240727 genetic variant in TOMM7 was associated with T2D of Chinese Dong individuals, and might enhance the risk of T2D by affecting the level of FPG.