Related Experiment Video
Updated: Jul 5, 2026

Infinium Assay for Large-scale SNP Genotyping Applications
Published on: November 19, 2013
Performance of commercial platforms for rapid genotyping of polymorphisms affecting warfarin dose
Cristi R King1, Rhonda M Porche-Sorbet, Brian F Gage
1Department of Internal Medicine, Washington University School of Medicine, St Louis, MO 63110, USA.
Abstract:
Initiation of warfarin therapy is associated with bleeding owing to its narrow therapeutic window and unpredictable therapeutic dose. Pharmacogenetic-based dosing algorithms can improve accuracy of initial warfarin dosing but require rapid genotyping for cytochrome P-450 2C9 (CYP2C9) *2 and *3 single nucleotide polymorphisms (SNPs) and a vitamin K epoxide reductase (VKORC1) SNP. We evaluated 4 commercial systems: INFINITI analyzer (AutoGenomics, Carlsbad, CA), Invader assay (Third Wave Technologies, Madison, WI), Tag-It Mutation Detection assay (Luminex Molecular Diagnostics, formerly Tm Bioscience, Toronto, Canada), and Pyrosequencing (Biotage, Uppsala, Sweden). We genotyped 112 DNA samples and resolved any discrepancies with bidirectional sequencing. The INFINITI analyzer was 100% accurate for all SNPs and required 8 hours. Invader and Tag-It were 100% accurate for CYP2C9 SNPs, 99% accurate for VKORC1 -1639/3673 SNP, and required 3 hours and 8 hours, respectively. Pyrosequencing was 99% accurate for CYP2C9 *2, 100% accurate for CYP2C9 *3, and 100% accurate for VKORC1 and required 4 hours. Current commercial platforms provide accurate and rapid genotypes for pharmacogenetic dosing during initiation of warfarin therapy.
Related Concept Videos
Pharmacogenetics of Drug Metabolism: Overview
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Principles of Pharmacogenetics: Types of Genetic Variants
Pharmacogenomics: Identification of New Drug Targets

