AJTR Copyright © 2009-All rights reserved. Published by e-Century Publishing Corporation, Madison, WI 53711
Am J Translational Res 2010;2(4):441-446

Original Article
Warfarin genotyping using three different platforms

Joel A. Lefferts, Mary C. Schwab, Uday B. Dandamudi, Hong-Kee Lee, Lionel D. Lewis, Gregory J. Tsongalis

Department of Pathology, Dartmouth-Hitchcock Medical Center and Dartmouth Medical School, Lebanon, NH
03756, USA; Department of Medicine, Dartmouth-Hitchcock Medical Center and Dartmouth Medical School,
Lebanon, NH 03756, USA; Norris Cotton Cancer Center, Lebanon, NH 03756, USA.

July 13, 2010; accepted July 23, 2010; available online July 25, 2010

Abstract: Genetic testing for common variants in the CYP2C9 and VKORC1 genes may provide useful clinical
information to guide dosing patients receiving oral warfarin.  Specifically, the CYP2C9*2, CYP2C9*3 and either the
VKORC1 -1639 G>A or VKORC1 1173C>T polymorphisms can be used to help predict an approximate warfarin
maintenance dose needed for a particular patient.  Although clinical uptake and use of this genotyping has been
slow, an increasing body of literature provides evidence of the clinical utility of supplementing traditional warfarin
dosing algorithms with a pharmacogenetic approach.  The availability of multiple methods for clinical genotyping
provides the opportunity for molecular diagnostic laboratories to introduce genotyping assays tailored to their
specific needs based on variables such as testing volumes, staffing, available instrumentation and needed
turnaround times.  Three assays (Invader, Verigene and TaqMan) designed to detect three genetic variations
associated with warfarin dosing are evaluated and compared as potential clinical tests to assist in patient care.  
Identical genotypes were reported by each assay for all samples tested but the assays were found to differ in
turnaround time, approval status by the U.S. Food and Drug Administration (FDA), requirements for amount of
input genomic DNA and other logistical factors that might make each assay more favorable in different settings.

Key words: Warfarin, CYP2C9, VKORC1, genotyping methods, Verigene, Invader, TaqMan PCR

Full Text  PDF

Address all correspondence to:
Gregory J. Tsongalis, PhD
Department of Pathology
Dartmouth Hitchcock Medical Center
1 Medical Center Drive
Lebanon, NH 03756
Tel: 603-650-5498, Fax: 603-650-4845
E-mail: gregory.j.tsongalis@hitchcock.org