Association between KCNJ11 & ABCC8 Genetic Polymorphism and Type 2 Diabetes in Egyptian Patients, AYAT I. GHANEM, SUZAN RUSHDY, MOHAMED MOKHTAR, MOHAMED A.M.ATIA and SHAIMAA A. SHOUMAN
Abstract
Background: Type 2 diabetes (T2D) is a complex disease that is caused by a complex interplay between genetic, epige-netic and environmental factors. While the major environmental factors, diet and activity level, are well known, identification of the genetic factors has been a challenge. The most important genes responsible for insulin secretion are KCNJ11 and ABCC8 which encode ATP-sensitive potassium (K-ATP) channels subunits in pancreatic ß-cells. The common poly-morphism of KCNJ11 gene is (E23K) which tightly linked with (S 1369A) variant of adjusted ABCC8 gene. Many studies reported that (E23K-S 1369A) variants either alone or together, form a risk haplotype that may serve as a predictor of pro-gression from impaired glucose tolerance to Type 2 diabetes. For best of our knowledge, no earlier genetic association studies with these SNPs were published concerning Egyptian population.
Objective: The objective of this study was to investigate the association between the common single nucleotide poly-morphism (SNP) of KCNJ1 1 and ABCC8 (E23K-S 1369A), respectively and type 2 diabetes mellitus in a case-control study of Egyptian population.
Subjects: The study comprised of 57 Type 2 diabetic patients (43 females and 14 males, mean age (54.21±7.59 years), and 33 unrelated healthy individuals (13 female and 20 male) considered as control group (mean age 50.83±7.5 years). We genotyped the two representative SNPs in KCNJ1 1 and ABCC8 by using TaqMan Allelic Discrimination Assay based Real-Time PCR.
Results: It was found that neither the E23K nor S 13 69A SNPs in KCNJ1 1 and ABCC8 genes, respectively were asso-ciated with type 2 diabetes in the studied sample of Egyptian population [OR=1.512 with 95% CI (0.621–3.678), p=0.360 and OR=1.842 with 95% CI (0.799-4.246), p=0.148]. In addition, no interactions between these two SNPs on the risk of type 2 diabetes were detected (p>0.05). However, it was confirmed that E23K variant in KCNJ11 was relatively in complete linkage disequilibrium with a second S 1369A variant in the neighboring ABCC8 gene forming a haplotype block (D’ = 0.221, r2=0.0487, c2=362.33).
Conclusions: We have demonstrated that (E23K-S 1369A) SNPs in KCNJ1 1 and ABCC8 genes are not associated with Type 2 diabetes mellitus in Egyptian diabetic patients.