BACKGROUND AND AIM Warfarin is the most frequently prescribed anticoagulant worldwide. However, warfarin therapy is associated with a high risk of bleeding and thromboembolic events because of a large interindividual dose-response variability. We investigated the effect of genetic and non genetic factors on warfarin dosage in a South Italian population in the attempt to setup an algorithm easil...

The objective of this study was to assess the relative influence of VKORC1 and CYP2C9 genetic variants on several clinical outcomes related to warfarin treatment. We conducted a retrospective cohort analysis of 172 anticoagulation clinic patients followed from warfarin initiation. We assessed the following clinical outcomes: time to stable dose; time in, above, and below therapeutic range; the ...

BACKGROUND Although catalytic properties of different genetic polymorphisms of VKORC1 and CYP2C9 products have been identified, there is limited study available regarding warfarin dose requirement in Iranian patient population. This study investigates the impact of these polymorphisms on 115 patients, referred to Payvand Clinical and Specialty Laboratory for determining the appropriate dose of ...

OBJECTIVE The aim was to investigate the frequency of genetic polymorphisms of cytochrome P4502C9 (CYP2C9) and vitamin K epoxide reductase complex subunit1 (VKORC1) and determine the effect of these polymorphisms on warfarin dose requirements in pediatric patients. METHODS Fifty-eight pediatric patients with cardiac disease, thrombophilia, or other conditions, taking a stable warfarin dose, a...

VKORC1 (vitamin K epoxide reductase complex subunit 1, 16p11.2) is the main genetic determinant of human response to oral anticoagulants of antivitamin K type (AVK). This gene was recently suggested to be a putative target of positive selection in East Asian populations. In this study, we genotyped the HGDP-CEPH Panel for six VKORC1 SNPs and downloaded chromosome 16 genotypes from the HGDP-CEPH...

BACKGROUND & OBJECTIVES The effects of vitamin K-dependent proteins in bone mineralization and vascular calcification and the implication of vitamin K epoxide reductase gene (VKORC1) 1173C>T polymorphism in warfarin sensitivity are well known. The main objective of the study was to investigate the relationship between VKORC1 1173C>T polymorphism, bone mineral density (BMD), and atherosclerosis ...

BACKGROUND Warfarin treatment has a narrow therapeutic range, requiring meticulous monitoring and dosage titration. Individual dosage requirement has recently partly been explained by genetic variation of the warfarin metabolizing enzyme CYP2C9 and the Vitamin K-activating enzyme VKORC1. In the WARIS-II study, comparing three different antithrombotic regimens after myocardial infarction, warfar...

The requirement of varying doses of warfarin for different individuals can be explained by environmental and genetic factors. We evaluated the frequency of vitamin K epoxide reductase complex subunit 1 (VKORC1) and cytochrome P450 2C9 (CYP2C9) variants together with patientdemographic characteristics and investigated their association with warfarin dose requirement with the ob...

Genotype-based algorithms that include VKORC1 and CYP2C9 genotypes are less predictive of warfarin dose variability in Africans as opposed to Europeans. Polymorphisms in GGCX, FPGS, or STX1B are associated with warfarin dose requirements in African-Americans. We sought to determine if they influenced warfarin dose in European-Americans, and another African population, specifically Egyptians. We...

Chronic oral anticoagulation with warfarin is difficult to maintain within the therapeutic range and requires frequent monitoring and dose adjustments. Variations in two genes, VKORC1 and CYP2C9, have been associated with variation in warfarin metabolism among individuals. Patients with CYP2C9*2 and *3 variants have longer times to dose stabilization and are at higher risk of serious and life-t...