Association analysis of genetic polymorphisms of TCF7L2, CDKAL1, SLC30A8, HHEX genes and microvascular complications of type 2 diabetes mellitus

Abstract

To study the associations of single nucleotide polymorphisms (SNPs) of TCF7L2, CDKAL1, SLC30A8, HHEX with diabetic retinopathy (DR) and nephropathy (DN) in type 2 diabetes mellitus. A total of 479 subjects with DR,248 with DN and 650 without DR or DN were recruited to assess the associations between SNPs of TCF7L2 (rs7903146, rs6585205, rs11196218), CDKAL1 (rs10946398,rs4712527), SLC30A8 (rs13266634, rs3802177, rs11558471) and HHEX (rs1111875, rs7923837) and the development of DR and DN. There were significant differences in genotypic and allele frequencies of rs11558471 (SLC30A8) between DR and control groups (P< 0.05), the odds ratio (OR) values of A and AA were 1.27 and 1.68. The distributions of genotype and allele frequency for rs11196218 (TCF7L2) were significantly different between DN and control group (P=0.0051,OR=1.37). However, the P value after Bonferroni correction showed no significant difference. No significant differences were found in the distributions of rs13266634 and rs3802177 (SLC30A8), rs10946398 (CDKAL1), rs6585205, rs7903146 and rs11196218 (TCF7L2) and rs7923837 (HHEX) between DR and control groups, and nor significant differences were found in distributions of rs6585205 (TCF7L2), rs4712527 (CDKAL1), rs13266634, rs3802177 and rs11558471 (SLC30A8), and 7923837 (HHEX) between DN and control groups, though for all comparison the OR values were greater than 1. Polymorphisms of SLC30A8 and TCF7L2 genes may be associated with the development of DR and DN, respectively. Association between the polymorphisms of CKDAL1, TCF7L2 and HHEX genes and DR, and between the polymorphisms of SLC30A8, HHEX and CDKAL1 genes and DN, cannot be excluded.