Intron 4 a/b polymorphism of the endothelial nitric oxide synthase gene is associated with both type 1 and type 2 diabetes in a genetically homogeneous population

• Published in: Human immunology Vol. 69; no. 4; pp. 279 - 283
• Main Authors: Galanakis, Emmanouil, Kofteridis, Diamantis, Stratigi, Kalliopi, Petraki, Eleni, Vazgiourakis, Vassilios, Fragouli, Eleni, Mamoulakis, Dimitrios, Boumpas, Dimitrios T, Goulielmos, George N
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2008
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Allergy and Immunology; Case-Control Studies; Child; Child, Preschool; Confidence Intervals; Diabetes Mellitus, Type 1 - epidemiology; Diabetes Mellitus, Type 1 - genetics; Diabetes Mellitus, Type 2 - epidemiology; Diabetes Mellitus, Type 2 - genetics; Endothelial nitric oxide synthase gene; Female; Gene Frequency; Gene polymorphisms; Genetic background; Genetic Predisposition to Disease; Genotype; Greece - epidemiology; Humans; Male; Middle Aged; Nitric Oxide Synthase Type III - genetics; Odds Ratio; Polymorphism, Genetic; Tandem Repeat Sequences; Type 1 diabetes; Type 2 diabetes; Greece; Type 2 diabetes; Gene polymorphisms; Genetic background; Type 1 diabetes; Endothelial nitric oxide synthase gene
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/j.humimm.2008.03.001

Summary Current classifications of diabetes distinguish between type 1 diabetes (T1D) and type 2 diabetes (T2D), however recent evidence highlights overlap between T1D and T2D. Earlier studies have suggested altered nitric oxide (NO) metabolism in both T1D and T2D. In the present case-control study, we investigated whether the endothelial NO synthase gene intron 4 a/b polymorphism is associated with T1D and T2D in the island of Crete, a well-defined area with genetically homogeneous population. Mutated allele “a” was more common in individuals with both T1D and T2D than in controls (odds ratio [OR] = 1.71, 95% confidence interval [CI] = 1.06–2.77, p = 0.013; and OR = 1.50, 95% CI = 0.930–2.42, p = 0.047, respectively). Mutated genotype (a/a or a/b) was more common in individuals with T1D than in nondiabetic individuals (OR = 1.93, 95% CI = 1.12–3.32, p = 0.008); this increased frequency was also observed for T2D, although not at a significant level (OR = 1.38, 95% CI = 0.802–2.37). No difference was found in the frequency of mutated allele a or mutated genotype (a/a or a/b) between T1D and T2D populations. In conclusion, our results indicate that allele a of the intron 4 endothelial NO synthase gene is associated with susceptibility to both T1D and T2D and may represent a common genetic factor for diabetes.