title: Association between -786TC polymorphism in the endothelial nitric oxide synthase gene and hypertension in the Tunisian population.
abstract: BACKGROUND
  Nitric oxide (NO) is produced by endothelial cells and serves as a potent vasodilator. Several lines of evidence have shown that NO plays an important role in the regulation of blood pressure and regional blood flow. Recent genetic studies have shown an association between the -786TC polymorphism in the endothelial nitric oxide synthase gene (NOS3) and coronary artery diseases, but any possible association with hypertension has been controversial. In the present study, we examined a possible association between the -786TC polymorphism of the NOS3 gene and hypertension in a sample of the Tunisian population.
  
  
  METHODS
  A total of 288 unrelated Tunisian patients with hypertension and 373 normotensive subjects were included in the study. The -786TC gene polymorphism was analyzed by PCR-RFLP.
  
  
  RESULTS
  A significant difference in genotype distribution and allele frequency was observed between patients and controls. Patients with hypertension had a frequency of 19.7% for CC genotype, 52.9% for TC genotype and 27.3% for TT genotype. The control had a frequency of 14.7% for the CC genotype, 47.2% for the TC genotype and 38.1% for the TT genotype (χ²=9.09, p=0.01). The hypertension patient group showed a significant higher frequency of the C allele compared to the controls (0.46 vs. 0.38; χ²=8.26, p=0.004). The odds ratio of hypertension for C vs. T allele frequencies was statistically significant 1.59 (1.14-2.21) at 95% CI, p = 0.004 in men, whereas it was non-significant in women 1.21 (0.87-1.67), p=0.23.
  
  
  CONCLUSIONS
  The present study showed a significant and independent association between the -786TC gene polymorphism (presence of C allele) and hypertension in the Tunisian population.
authors.affiliation: Research Laboratory LR99ES11, Department of Biochemistry, Rabta University Hospital, Tunis, Tunisia. jemaa_riadh@yahoo.fr
authors.forename: Riadh
authors.initials: R
authors.lastname: Jemaa
authors.forename: Amani
authors.initials: A
authors.lastname: Kallel
authors.forename: Yousra
authors.initials: Y
authors.lastname: Sediri
authors.forename: Souheil
authors.initials: S
authors.lastname: Omar
authors.forename: Moncef
authors.initials: M
authors.lastname: Feki
authors.forename: Monia
authors.initials: M
authors.lastname: Elasmi
authors.forename: Samah
authors.initials: S
authors.lastname: Haj-Taieb
authors.forename: Haïfa
authors.initials: H
authors.lastname: Sanhaji
authors.forename: Naziha
authors.initials: N
authors.lastname: Kaabachi
mesh_terms: D016001:Confidence Intervals; D003710:Demography; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D006973:Hypertension / Q000201:enzymology* / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012727:Sex Characteristics; D014416:Tunisia
chemical_list: C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III