This study aimed to investigate relationships between times in therapeutic range (TTR) or warfarin sensitivity indexes (WSI) and VKORC1-1639G>A and CYP2C9 polymorphisms in patients with left ventricular assist devices (LVAD).
We found a 2.3-fold increase in mean dose for normal sensitivity patients (wild-type <i>VKORC1/CYP2C9</i> genotypes) compared to the other groups (moderate and high sensitivity); 31.5% of the patients in our study group had warfarin sensitivity-related genotypes.
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 1173T and -1639A allele variants in VKORC1 gene, associated with warfarin sensitivity, were present, as expected, mostly in low dose patients while 3730A allele, linked to warfarin resistance, has been found only in high dose patients.
A cell culture-based, indirect VKOR assay was developed and characterized that accurately reports warfarin sensitivity or resistance for wild-type and variant VKORC1 proteins.
The effects of genetic polymorphisms at the vitamin K epoxide reductase [VKORC1] and cytochrome P450 2C9 [CYP2C9] loci have been increasingly acknowledged as contributory factors of enhanced warfarin sensitivity.
To investigate the contribution of genetic polymorphisms of vitamin K epoxide reductase complex subunit 1 gene VKORC1-1639G>A, cytochrome P450 2C9 gene (CYP2C9), EPHXI, and clinical factors to warfarin sensitivity in southwest Chinese Han patients with mechanical heart valve prostheses.
To establish individualized warfarin therapy, we investigated the contribution of genetic variations of vitamin K epoxide reductase complex subunit 1 gene (VKORC1) -1639 G>A and Cytochrome P450 2C9 gene (CYP2C9) and clinical factors on warfarin sensitivity in Japanese patients.
We determined DNA sequence variants in CYP2C9 and VKORC1 in 16 Chinese patients having warfarin sensitivity (< or = 1.5 mg/day, n = 11) or resistance (> or = 6.0 mg/day, n = 5), 104 randomly selected Chinese patients receiving warfarin, 95 normal Chinese controls and 92 normal Caucasians.