Warfarin Sensitivity/Resistance SNPs

Analysis of SNPs in the VKORC1, CYP2C9 & CYP4F2 genes associated with Warfarin resistance or sensitivity.
Clinical details: 
Some patients show an apparent resistance or sensitivity to Warfarin when started on standard dosing regimes.
Individuals with the CYP2C9*2 and CYP2C9*3 genotype show impaired metabolism of warfarin and, therefore, require a lower dose compared to CYP2C9*1 individuals.
The T allele for the VKCORC1 1173C>T polymorphism is associated with a lower dose requirement.
Individuals homozygous (T/T) for the CYP4F2 450C>T polymorphism show a mild resistance, requiring approximately 1mg/day extra warfarin compared to C/C individuals.
Reference range: 


Synonyms or keywords: 
VKORC1 CYP2C9 CYP4F2 Warfarin resistance Warfarin sensitivity
Sample type and Volume required: 
1 x Edta
Call in advance: 
Turnaround time: 
14 days
Storage and transport: 
transport at ambient temperature
Molecular Haemostasis Laboratory at St Thomas'
020 7188 2798
Haemostasis and Thrombosis
North Wing - 4th floor
St Thomas' Hospital
Westminster Bridge Road
London SE1 7EH

Laboratory opening times
Monday - Friday 09.00 - 17.00
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 14/03/2017