Rapid triplex asymmetric real-time PCR hybridization probe assay for the joint genotyping of F2, F5 and F12.

Introduction: The Factor 5 Leiden mutation and the G20210A variant of Factor 2 are two important risk factors for hereditary thromboembolism. Several reports have demonstrated that homozygous carriers for C46T mutation of the Factor 12 gene is associated with a significant increased risk for the development of coronary disease as well as cerebral and peripheral venous thrombosis.

Design And Methods: We develop a rapid and feasible asymmetric multiplex real-time PCR-based method using fluorescence resonance emission transfer (FRET) probes followed by a melting temperature (T(m)) curve assay for the simultaneous clinical diagnosis of F2, F5 and F12 mutations in a 10 microl closed tube. This new tool uses three different fluorescence channels in a LightCycler 2.0 for the robust genotyping of each one of the mutations included in the reaction.

Results: Assay evaluation performed on 67 DNA samples previously genotyped with reference methods resulted in full concordance of results for the three mutations tested. Higher asymmetric ratio of primer pair concentration significantly increased the efficiency of the melting peak assay used for the mutation genotyping without modifying the Crossing Point (CP) obtained from the amplification curves.

Conclusions: To our knowledge this is the first triplex real-time PCR FRET-based assay reported in bibliography that allows a rapid and simultaneous genotyping of these three thrombosis risk factors. This new and rapid tool may contribute to the better understanding of the interrelations or contributions of these gene mutations to different thrombotic or coronary disease-related events.