Alzheimer's disease (AD) is the leading cause of dementia. Several studies indicate a possible relationship between different genes and Alzheimer's disease. To further investigate, we have analyzed the association between the bleomycin hydrolase (BLMH) and apolipoprotein E (ApoE) polymorphisms in 93 AD patients and age- and sex-matched 113 controls from the Tunisian population. The frequency of ApoE epsilon 4 allele was found to differ significantly in AD patients compared to the control [29.5% vs. 8.8 (χ (2) = 26, df = 1, p < 0.001)] leading to an increased risk of AD in subjects with this allele (OR = 3.29, 95% CI = 1.7-6.5; p = 0.001]. This risk was found to decrease from OR = 8.4, CI = 3.3-23; p < 0.001 in subjects less than 75 years old to OR = 1.2, CI = 1.031-14; p = 0.0297 in subjects 75 years and older. No association was observed between carrying the BLMH-G genotype and AD in ε4 negative or positive subjects.

Objective:By releasing mediators, like nitric oxide (NO), vascular endothelium is considered so significant in the process of atherosclerotic. In fact, the major functions of NO consist in inhibiting the activation of platelet, relaxing the muscles (vascular and smooth ones), and modulating the growth and the migration of cells (vascular and smooth ones). Therefore, this process makes the endothelial nitric oxide synthase (NOS3) considerably important because it possesses atheroprotective activity. Polymophisms, rs1808593 (10G/T) as well as rs891512 (G24943A) within NOS3 gene, play major role in the coronary artery disease (CAD) development. The aim of the study is to evaluate the relationship between the 10G/T and G24943A polymorphisms and the CAD among Tunisian individuals.Methods:We included, in this survey, a set of 274 patients suffering from CAD together with 162 normotensive subjects. The PCR-RFLP was app- lied to analyze the polymorphism of intron 23 (10G/T) gene, while the ASA-PCR was used to analyze the intronic G24943A gene polymorphism. Overall and subgroup analyses were performed. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association bet- ween NOS3 10G/T and G24943A polymorphisms as well as CAD risk. Statistical analysis was performed with SPSS V.10.Results:The genotype frequencies for G24943A polymorphism differed significantly between the CAD patients and the controls. The former had a frequency of 11.4% for the AA genotype, 34.7% for the GA genotype and 53.9% for the GG genotype. The latter had a frequency of only 2.5% for the AA genotype, 29.7% for the GA genotype and 67.7% for the GG genotype (χ2=7.62; OR=1.79; p=0.006). The CAD patient group showed a significantly-higher frequency of the A allele compared to the controls (0.28 vs. 0.16; χ2=15.20; p<0.001). The odds ratio of CAD for A vs. G allele frequency was statistically significant 1.99 (1.4–2.82) at 95% CI. The genotype distribution for the 3 investigated variants of 10G/T were not significantly different between CAD and control subjects (χ2=1.46; OR=1.72; p=0.22). Whereas, 10G/T has revealed barely allelic (χ2=4.45; OR=2.3; p=0.034) correlation with coronary artery diseaseConclusion:The present study was designed so that there would be an association between the CAD and NOS3 polymorphism (G24943A). Howe- ver, these results have proven that the polymorphism of 10G/T is not associated with CAD in the Tunisian population.

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Background: Nitric oxide (NO) plays a major role in the regulation of vascular tone associations between NO genotypes. Coronary artery disease (CAD) and other risk factors have been described by many authors. The aim of this study was to investigate the role of endothelial nitric oxide synthase (eNOS) gene intron 4a/b variable number of tandem repeats (VNTR) polymorphism and other risk factors in the developement of CAD in subjects of the Tunisian population. Method: A total of 274 Tunisian patients with CAD and 162 healthy controls were included in the study. The eNOS gene inton 4a4b variable number of tandem repeats polymorphism was analysed by PCR. The plasma lipid levels and other risk factors were also determined in all subjects. Results: A significant differences in genotype distribution and allele frequency was observed between patients and controls. Patients with CAD had a frequency of 2.4% for the 4a4a genotype, 63.9% for the 4a4b genotype and 33.7% for the 4b4b genotype. The controls had a frequency of only 6.3% for the 4a4a genotype, 30.4% for the 4a4b genotype and 63.3% for the 4b4b genotype (2=43.75, p=0.000). The CAD patient group showed a significant higer frequency of the 4a allele compared to the controls (0.34 vs. 0.21; 2 =15.31, p=0.000). The odds ratio of CAD for 4a vs. 4b allele frequency was statistically significant 1.9 [1.37-2.64] at 95% CI. The mean serum NO levels in CAD was no significant association between the patients and the control group (p=0.49). Conclusion: The present study showed a significant and independent association between the eNOS 4a4b gene polymorphism (presence of 4a allele) and CAD but no significant difference between eNOS genotypes and NOx concentrations in CAD patients and controls in the Tunisian population.