The role of ACE gene polymorphism on pathogenesis of ischemic stroke.

Aim: to describe the role of ACE gene polymorphism on pathogenesis of ischemic stroke in patients with the history of hypertension. The study was conducted in a population of Palembang city.

Methods: approximately 3 ml of peripheral blood samples were obtained by using venipuncture on antecubital vein. The samples were collected in tubes that contained ethylene diamine tetraacetic acid (EDTA) for DNA analysis. The DNA was extracted from leukocytes according to the standard DNAzol® Extraction Protocol. Samples were stored at -80°C until the analysis. Template DNA was then amplified by using a pair of sense oligonucleotide primer of 5'-CTGG AGACC ACTCCCATCCTTTCT-3' and antisense primer 5'-GATGGTGGCCATCAC ATTCGTC AGAT-3', 10 pmol of each primer. The PCR mixture contained 20 ng of genomic DNA, 3 mM MgCl2, 50 mM KCl, 10 mM Tris-HCl pH 8.4, 5% dimethyl-sulphoxide (DMSO), each of 0,5 mM deoxyribonucleoside triphosphate (dNTPs) and 1 unit of Taq polymerase in a final volume of 50 μL. The DNA was amplified by 30 cycles; denaturation at 940C for 1 min, annealing at 580C for 1 min, and extension at 720C for 2 min, followed by a final extension at 720C for 4 min by using PCR Thermal (Icycler, Biorad, USA). PCR products were separated by electrophoresis on a 2% agarosa gel, and identified by ethidium bromide (0.1%) staining, and finally visualized by ultraviolet light. They were documented by using the geldoc (Biorad, USA). The PCR product is a 190 bp fragment in the absence of insertion (D) and a 490 bp fragment in the presence of insertion (I).

Results: ischemic stroke with hypertension or with the history of hypertension was found more frequently in male (70%) and ≥ 55 year old subjects (60.0%). The study showed that the frequency of II genotype was higher than DI and DD. Moreover, the frequency of I allele was higher than D allele. In healthy normotensive group, the results remained the same. However, different results were found in infarct-stroke group with hypertension history in which the frequency of DI genotype was higher than in II genotype and the DD. The study showed that there was no significant correlation (p=0.188) between ACE gene polymorphism and infarct stroke in subjects with the history of hypertension. ACE gene just has approximately 5% role in developing ischemic stroke.

Conclusion: there is no significant correlation between ACE gene polymorphism and the development of ischemic stroke in patients with history of hypertension of the population in Palembang. However, the study showed that there is a different pattern of genetic control on ACE compared to previous studies ever done in Caucasians.