Validation of Genome-Wide Association Studies (GWAS)-ldentified Type 2 Diabetes Mellitus Risk Variants in Pakistani Pashtun Population

Abstract

Objective. Recent GWAS largely conducted in European populations have successfully identified multiple genetic risk variants associated with Type 2 Diabetes Mellitus (T2DM). However, the effects conferred by these variants in the Pakistani population have not yet been fully elucidated. The objective of this study was to examine European GWAS-identified T2DM risk variants in the Pakistani Pashtun population to better understand the shared genetic basis of T2DM in the European and Pakistani cohorts. Methodology. A total of 100 T2DM patients and 100 healthy volunteers of Pashtun ethnicity were enrolled in this study. Both groups were genotyped for 8 selected single nucleotide polymorphisms (SNPs) using the Sequenom MassARRAY® platform. The association between selected SNPs and T2DM was determined by using appropriate statistical tests. Results. Of the 8 studied SNPs, 5 SNPs, SLC30A8/ rs13266634 (p=0.031, OR=2.13), IGF2BP2/ rs4402960 (p=0.001, OR=3.01), KCNJ11/ rs5219 (p=0.042, OR=1.78), PPARG/ rs1801282 (p=0.042, OR=2.81) and TCF7L2/ rs7903146 (p=0.00006, 3.41) had significant association with T2DM. SNP GLIS3/ rs7041847 (p=0.051, OR=2.01) showed no sufficient evidence of association. SNPs KCNQ1/ rs2237892 (p=0.140, OR=1.61) and HHEX/IDE/ s1111875 (p=0.112, OR=1.31) showed opposite allelic effects and were not validated for T2DM risk in the study population. Among the studied SNPs, TCF7L2/ rs7903146 showed the most significant association. Conclusion. Our study finding indicates that selected genome-wide significant T2DM risk variants previously identified in European descent also increase the risk of developing T2DM in the Pakistani Pashtun population.