A genotyping method for VKORC1 1173C > T by Pyrosequencing technology.

Area of Science:

• Pharmacogenomics
• Molecular Biology
• Genetics

Background:

• Warfarin, an oral anticoagulant, is inhibited by drugs targeting Vitamin K epoxide reductase complex subunit 1 (VKORC1).
• A specific single nucleotide polymorphism (SNP), rs9934438 (VKORC1 1173C>T), is linked to reduced warfarin dose requirements and variable international normalized ratio (INR) response.
• The VKORC1*2 haplotype is associated with these clinical observations.

Purpose of the Study:

• To develop and validate a rapid genotyping method for the VKORC1 1173C>T SNP.
• To facilitate personalized warfarin therapy by identifying patients requiring lower doses.

Main Methods:

• Development of a rapid genotyping assay utilizing Pyrosequencing technology.
• Optimization of post-PCR sample preparation (<1 hour) and DNA sequencing (<15 minutes) for 96 samples.
• Comparison of the Pyrosequencing method with a previously established dHPLC method.

Main Results:

• The Pyrosequencing method provides a fast and efficient way to genotype the VKORC1 1173C>T SNP.
• Genotype frequencies in a Swedish population were 38% wild-type, 40% heterozygote, and 22% homozygote.
• The T-allele frequency of 0.42 in the Swedish population matched previously reported frequencies for Germans.

Conclusions:

• The developed Pyrosequencing method is a rapid and reliable tool for VKORC1 1173C>T genotyping.
• This assay can identify patients likely to require lower warfarin doses, improving oral anticoagulant therapy management.
• Genotyping this SNP is essential for predicting warfarin response and optimizing patient treatment.