Type 1 diabetes (T1D) is a chronic autoimmune disease with a complex interrelation of genetic and environmental factors. Genetic studies have reported HLA and non-HLA loci as significant contributors to T1D. However, the genetic basis of T1D among Emiratis is unexplored. This study aims to determine the contribution of four genes PTPN22, CTLA-4, IL2-RA, and INS to T1D risk among Emiratis. The association between variants in PTPN22 (rs2476601, rs1310182), CTLA-4 (rs11571316, rs231775, rs3087243, rs1427676, and rs231727), IL2-RA (rs7090530), and INS (rs7111341) with T1D was tested in 310 Emiratis (139 T1D patients and 171 controls). A significant association was found at rs1310182, and rs2476601 both in PTPN22, rs3087243, and rs231775 both in CTLA-4, and rs12251307 in IL2-RA. Moreover, a haplotype constituted from GG and AG genotypes at rs231727 and rs231775, respectively, in CTLA-4 was significantly associated with an increased T1D risk. The cumulative effects of risk alleles for all significantly associated SNPs showed 11.8 higher relative risk for T1D for those who carry 5-6 compared to 0-1 risk alleles. This study illustrated that PTPN22, CTLA-4, and IL2-RA gene variants could confer risk alleles for T1D among the Emirati population.
Keywords: CTLA-4; Emirati; IL2-RA; INS; PTPN22; genetic polymorphism; type 1 diabetes.
© 2020 John Wiley & Sons Ltd/University College London.