Identification of genetic risk variants for Type-2 Diabetes mellitus in Pakistani Pashtun population: A case-control association study

Background and objective: Pakistan, a South Asian developing country, is experiencing a rapid increase in number of diabetes cases. High prevalence ratio of diabetes in Pakistani population and lack of genetic research studies prompted us to design this study. This present study investigated Pakistani Pashtun population for (known and novel SNPs) and its possible correlation with Type-2 Diabetes Mellitus (T2DM).

Methods: This two stage (discovery & validation stage), case-control association study included one thousand individuals (Patients with T2DM=500 & controls=500) from eight districts of Khyber Pakhtunkhwa Pakistan. The study duration/period was from March 2018 to January 2020. In the first stage (the discovery stage) the target population was screened for known and novel T2DM-associated genetic markers. In the validation stage, identified variants were confirmed for T2DM association using MassARRAY genotyping and association analysis.

Results: Exome sequencing detected eleven known and four novel/new genetic markers in the study population. Novel variants were preferred over the known for follow-up analysis/validation. Among the identified variants strong associations were confirmed for the following variants; rs1781133/ANKRD65 (OR=2.10, 95%Cl=1.06-3.08, P=0.003) rs2274791/TTLL10 (OR=1.97, 95%Cl=1.36-2.62, P=0.025), rs71628928/RNF223 (OR=1.82, 95%Cl=0.97-1.92, P=0.041), and rs609805/SCNN1D (OR=2.21, 95%Cl=1.92-3.09, P=0.001) with T2DM; other reported variants showed no noticeable association (having P>0.05) with T2DM.

Conclusion: This study reports new genetic risk variants for T2DM in Pashtun population providing valuable insights into the genetic basis of T2DM in this group.