Insertion/deletion polymorphism of the angiotensin converting enzyme (ACE) gene is a key component of the Renin-Angiotensin-Aldosterone System (RAAS). It has been proposed as an independent factor for hypertension and other cardiovascular diseases. Consequently, it has been extensively studied in various populations. The aim of this study is to investigate I/D polymorphism of ACE gene and its connection to hypertension in population of Tuzla Canton (Bosnia & Herzegovina). The study included 60 hypertensive subjects and 60 healthy control subjects with no risk factors for hypertension. I/D polymorphism was genotyped by polymerase chain reaction followed by gel electrophoresis and data obtained were statistically analysed using Chi square test. Odd’s ratios were calculated with a 95% confidence interval. P-value < 0.05 was considered significant. Odd’s ratios were calculated with a 95% confidence interval. P-value <0.05 was considered significant. Higher frequency of genotype D/D and allele D was determined in subjects with hypertension compared to control subjects but there is no statistical significance (p>0.05). However, statistically significant association was found in compared groups of subjects with genotypes DD + ID, in regards to genotype I/I (p<0.05). The results indicate the conclusion that ACE I/D polymorphism cannot be considered the main risk factor for development of hypertension, but its influence should be investigated together with other genetic and acquired risk factors that are associated with hypertension. This research contributes to the on-going exploration of molecular-genetic associations with hypertension.

Molecular-genetic diagnostics of polygenic diseases is a new and interesting area in laboratory diagnostics, especially in the area of cardiovascular diseases, as one of the leading causes of mortality in the world population. Aims: The aim of the paper was to analyse variants of the endothelial nitric oxide synthase gene (NOS3) (Glu298Asp/G894T) in the human population of Tuzla Canton in relation to cardiovascular diseases. Study Design: The study included 112 respondents of both sexes over 18 years old. The experimental group for the analysis of the polymorphism (Glu298Asp) of the endothelial nitric oxide synthase gene included 56 respondents of both sexes with cardiovascular disease (hypertension), while the control group comprised 56 healthy respondents of both sexes without a prior history of cardiovascular disease (sample/control). Place and Duration of Study: Blood sampling was performed at Medical Center "Plava Poliklinika", “Plava Medical Group”, Department of Biochemistry, Microbiology and Genetics, Tuzla. DNA isolation and molecular-genetic analysis of the samples were performed in Laboratory for scientific research at the Department of Biology, Faculty of Natural Sciences and Mathematics in Tuzla. Methodology: The genotyping of eNOS Glu298Asp polymorphism for all respondents was determined by an optimized method based on PCR-RFLP reaction. Results: In the total sample of respondents, the highest genotype frequencies of the eNOS gene were recorded for the GG genotype (53.5%) and the GT genotype (35.7%). The lowest frequency was recorded for the TT genotype, which was 10.8%. Conclusion: The results obtained in the study provide good guidelines for further study of a molecular-genetic association between a high number of gene candidates and cardiovascular diseases, which will contribute to the incorporation of these results into the existing regional and European genetic database.