Protective effect of the rare variant rs13266634C/T of the SLC30A8 gene in the genetic background of the development of type 2 diabetes in Turkish population

Background: The SLC30A8 gene encodes zinc transporter-8 (ZnT8), highly expressed in insulin-secreting pancreatic beta cells, and may contribute to insulin processing and secretion. The SNP 13266634C/T (R325W change) in the SLC30A8 gene has been associated with type 2 diabetes (T2D) development. Genome-wide association studies and subsequent population studies including Europeans and Asians have demonstrated that the rare allele T (Trp325) of SNP 13266634 in the SLC30A8 gene is protective against T2D. Aim: We aimed to investigate whether the SNP rs13266634C/T is associated with T2D and its phenotypes in Turkey, which geographically connects Asia and Europe. Materials and methods: In our study, 650 nonobese individuals (366 T2D and 284 healthy individuals) were enrolled. Target SNP was genotyped by real-time PCR using the LightSNiP Genotyping Assay System. Results: The frequency of the T allele was lower in the T2D group than in the healthy control group (14.6% vs. 24.5%, respectively). The rare variant T of SNP rs13266634 in SLC30A8, located in the last exon of the gene, is associated with an increased c-peptide level, and it was 47.2% protective against type 2 diabetes compared to the C allele (OR = 0.528, 95% CI: 0.399–0.699, p <.001). Conclusions: Our findings indicate consistently with other studies that a rare variant of rs13266634C/T is protective against T2D, as the related first report in the nonobese Turkish population. Comprehensive studies to better understand the envisaged vital molecular role of SLC30A8 in pancreatic beta cells may contribute to developing therapeutic approaches.