Vitamin K epoxide reductase complex 1 (VKORC1) gene polymorphisms in population of Eastern Croatia.

Vitamin K epoxide reductase (VKOR) is a key enzyme in the y-carboxylation of proteins associated with important bodily functions (coagulation, bone metabolism, etc.). This feature is particularly used in warfarin therapy, which blocks the VKOR enzyme and leads to production of dysfunctional coagulation proteins. Genetic factors, particularly vitamin K epoxide reductase complex 1 (VKORC1) gene, have greatest influence on warfarin therapy. The aim of this study was to determine the distribution of VKORC1 1173C > T and VKORC1 -1639G > A polymorphisms, which are most important for warfarin therapy. We investigated 420 unrelated healthy individuals, mostly blood donors, from region of the Eastern Croatia. Both investigated polymorphisms were in perfect linkage disequilibrium (LD) and showed identical results. 151 patients (36%) were homozygous for the wild-type (C/C and G/G), 196 (47%) were heterozygous (C/T and G/A) and 73 (17%) were homozygous for the variant allele (T/T and A/A). Number of normal alleles among individuals was 498 (59.3%), and number of variant alleles was 342 (40.7%). The data obtained are in good agreement with the results of studies in other European populations.