Genetic determinants of heritable venous thrombosis:: Genotyping methods for factor VLeiden A1691G, methylenetetrahydrofolate reductase C677T, prothrombin G20210A mutation, and algorithms for venous thrombosis investigations

Objectives: To implement cost effective and clinically relevant thrombophilic genotyping and homocysteine analysis in our coagulation laboratory. Methods: We describe genotyping assays for three of the genetic defects associated with hereditary thrombosis: factor V-Leiden A1691G, methylenetetrahydrofolate reductase C677T, and prothrombin gene G20210A. A second confirmatory assay for factor V-Leiden using allele specific oligonucleotide polymerase chain reaction is also presented. We suggest an algorithm for the rational integration of the traditional assays routinely used to investigate venous thrombosis with genotyping and plasma homocysteine measurements. Results: These polymerase chain reaction based assays were designed to be performed under identical reaction conditions, permitting simultaneous setup, amplification, digestion, and analysis. Conclusions: The three genotyping assays presented are robust and relatively easy to perform. Use of an algorithm will ensure efficient resource utilization and minimize unnecessary testing. Copyright (C) 1999 The Canadian Society of Clinical Chemists.