en خون شناسی و بانک خون Hematology & Blood Banking پژوهشي Research - <div style="text-align: justify;"><strong>Background and Aims:</strong> Warfarin is an anticoagulant agent used for many years in treating various clinical conditions such as thromboembolisms in cardiovascular disease. Some patients require different doses of warfarin to reach the therapeutic international normalized ratio ratio. These patients have specific demographic characteristics. Genetic polymorphisms in specific genes have been reported to be an essential factor in response to warfarin. The present study investigated the effect of these polymorphisms of genes on warfarin dose necessities in pediatric of <em>VCORC1</em> gene in patients.<br> <strong>Material and Methods:</strong> Ninety-five patients with cardiovascular disease, who were receiving warfarin for at least three months, enrolled in the present cross-sectional study. Their genomic DNA was extracted from their peripheral blood, and the <em>VKORC1</em> (<em>rs9923231</em>) polymorphism was evaluated by polymerase chain reaction and sequencing.<br> <strong>Results:</strong> Among the study population, 48 patients (50.5%) had TC genotype and, 21 (22.1%) and 9 (9.5%) patients have TT and CC genotype, respectively. There was no significant relation between Warfarin dose and <em>VCORC1</em> genotype in our population (p<0.05).&nbsp;<br> <strong>Conclusions:</strong> The <em>VKORC1</em> polymorphism (<em>rs9923231</em>) did not significantly affect the warfarin required for cardiovascular disease patients. Further studies evaluating other genes such as <em>CYP2C9</em> polymorphisms in our population are warranted.</div> - Cardiovascular disease, Genotype, Polymorphism, VKORC1, Warfarin 251 257 http://ijml.ssu.ac.ir/browse.php?a_code=A-10-385-1&slc_lang=en&sid=1 Tahmine Zafari - - sunny.road@yahoo.com No Department of Pediatric Cardiology, Mashhad Medical Sciences Branch, Islamic Azad University, Mashhad, Iran Narges Ajilian - - medreserch2020@gmail.com No Department of Pediatric Cardiology, Mashhad Medical Sciences Branch, Islamic Azad University, Mashhad, Iran Atena Mansouri - - mansouri_atena@yahoo.com No Innovated Medical Research Center & Department of Immunology, Mashhad Branch, Islamic Azad University, Mashhad, Iran Ariane Sadr-Nabavi No Medical Genetics Research Center, Basic Medical Sciences Institute, Mashhad University of Medical Sciences, Mashhad, Iran Seyed-Alireza Esmaeili - - imunoman2009@gmail.com 0000-0002-9371-4170 Yes Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Reza Jafarzadeh Esfehani - - MansouriA932@mums.ac.ir No Medical Genetics Research Center, Basic Medical Sciences Institute, Mashhad University of Medical Sciences, Mashhad, Iran Saeed Abtahi - - sabtahimd@yahoo.com No Department of Pediatric Cardiology, Mashhad Medical Sciences Branch, Islamic Azad University, Mashhad, Iran