Abstract
Venous thrombosis (VT) is a multi-factorial disorder with both congenital and acquired risk factors. Mutations in several genes, such as factor V, prothrombin and methylene tetrahydrofolate reductase (MTHFR), are considered risk factors for thrombophilia. Since multiple mutations compound the risk for (VT), simultaneous discovery of mutations could directly alter patient management. In this study, we employed the GeneOhm ePlex™ platform to simultaneously detect genetic polymorphisms for six markers: factor V Leiden (FVL) and HR2A45374G, prothrombin G20210A, MTHFR C677T and A1298C, and plasminogen activator inhibitor 1 (4G/5G). Fifty-one patient samples were selected. Each sample was genotyped for all six markers on the GeneOhm ePlex™ electrochemical array and data from functional studies were analyzed and compared to the genotyping results. Among the 51 patients, 16 were tested for activated protein C resistance and the average values were 1.22, 1.76 and 2.64 for FVL homozygous, heterozygous and wild type normal patients, respectively. In addition, the average plasma homocysteine levels measured in 17 patients were 15.40, 6.42 and 11.93, 12.63 mmol/L for MTHFR C677T homozygous, heterozygous and MTHFR A1298C heterozygous and C677T/A1298C double heterozygous, respectively. Furthermore, 10 out of 11 patients with history of deep venous thrombosis (DVT) and/or pulmonary embolism (PE) displayed genetic abnormalities in FVL or prothrombin G20210A. The other patient with history of both DVT and PE showed homozygous in MTHFR C677T with high plasma homocysteine level (22.3 mmol/L) and heterozygous mutation in PAI-1. This study demonstrates the principle of multiplexed molecular diagnostics for the polymorphisms associated with thrombophilia and the utility of the GeneOhm ePlex platform. The study is being expanded to test a larger set of samples to establish the relationship between genetic polymorphism and corresponding clinical outcome for all six markers.
Prothrombin G20210A mutation, and not factor V Leiden mutation, is a risk factor for cerebral venous thrombosis in Brazilian patients