Frequency of Polymorphisms Associated with VKORC1 Gene in Thai Blood Donors and Patients Receiving Warfarin

บทคัดย่อ

Abstract :

Warfarin, an oral anticoagulant, is commonly complicated by the unpredictable dose response. Genetic predisposing factors, gender, age and

weight affect the patient’sr esponsei ndividually. T hiss tudya imeda td eterminin
 the frequency of polymorphisms of vitamin K epoxide reductase complex subunit 1 (VKORC1) among 319
Thai  blood donors and 106 patients receiving warfarin, and functional effects of VKORC 1 polymorphisms in responsible
 for warfarin dosage. The results revealed that the frequencies of polymorphisms at -1639 of VKORC 1 among
blood  donors and patients were similar: AA (61.1% vs. 63.2%), GA (33.6% vs. 31.1%) and GG (5.3% vs. 5.7%). Patients
with  homozygous AA required significantly lower warfarin doses (24.0±10.2 mg/week) compared to those with GG
(39.5± 21.3 mg/week) and GA (37.6±13.0 mg/week) with the p values of <0.001. The body surface area was proportional
 to the warfarin dose with a p value of 0.006 while the increasing age was inversely associated with the warfarin
dose with a p value of <0.001. Comparison among various factors to the warfarin dose revealed that polymorphisms
of  VKORC1 had the strongest effect on the warfarin dose requirement. Patients with AA polymorphisms commonly
found  in Thai population required lowest warfarin doses.