Factor V Leiden and natural selection

R147W in PROC Gene Is a Risk Factor of Thromboembolism in Thai Children

The p.R147W mutation, the c.C6152T in exon 7, causing a change in amino acid from arginine to tryptophan of the PROC gene has been reported as a common mutation in Taiwanese populations with venous thromboembolism (VTE). The present study aimed to identify the prevalence of p.R147W in the Thai population and children with TE and the risk of developing TE. Patients aged ≤18 years diagnosed with TE were enrolled. The PROC gene was amplified by polymerase chain reaction using a specific primer in exon 7. The restriction fragment length polymorphism was designed using MwoI restriction enzyme. A total of 184 patients and 690 controls were enrolled. The most common diagnosis of TE was arterial ischemic stroke (AIS), at 100 (54.3%), followed by VTE, at 38 (20.6%), and cerebral venous sinus thrombosis (CVST), at 23 (12.5%). The prevalence of heterozygous and homozygous p.R147W in patients and controls was 9.5% versus 5.8% and 2.7% versus 0.1%, respectively. Heterozygous p.R147W had odds ratios (ORs) of 1.8 (95% confidence interval [CI]: 1.0-3.2, P = .04), 3.2 (95% CI: 1.2-8.2, P = .009), and 4.5 (95% CI: 1.6-12.8, P = .002) of developing overall TE, VTE, and CVST, respectively. Homozygous p.R147W had ORs of 20.2 (95% CI: 2.3-173.7, P < .001), 21.4 (95% CI: 2.2-207.9, P < .001), and 43.3 (95% CI: 3.8-490.6, P < .001) of developing overall TE, AIS, and CVST, respectively. This study suggested that p.R147W is a common mutation and increased risk of TE in Thai children.

Factor V Leiden and Prothrombin 20210A Mutations among Turkish Pediatric Leukemia Patients

This study was undertaken to determine the prevalence of the Factor V 1691 G-A and PT 20210 G-A mutations in Turkish children with leukemia. We genotyped 135 pediatric leukemia patients with for these mutations. Eleven (8%) of the 135 patients were heterozygous for the FV 1691 G-A mutation. Seven (5,1%) of the patients carried the PT 20210 G-A heterozygous mutation. Of the 135 patients, only three had thrombotic event, none of which had these two mutations, which is common in Turkish population. Our findings revealed a controversial compared to the previous reports, which needs further investigation.

The effect of FV-426 G/A gene variation on the occurrence of thrombosis

Factor V (FV) plays a crucial role in both procoagulant and anticoagulant pathways. It was indicated that -426G/A change in the promoter of the FV gene may have an effect on the occurrence of thrombosis. We aimed to investigate the effect of -426G/A gene variation on thrombus formation in the thrombosis patients of age 0 and 18 years and 70 years and older. The study included 179 patients with the diagnosis of thromboembolism and also 221 healthy individuals as controls. The Polymerase chain reaction-restriction fragment length polymorphism method was used to detect -426G/A. It was observed that carrying AA genotype does not have a significant risk of thrombosis between the patients and controls (for 0-18 age group P = .96, odds ratio [OR]: 1.13 [0.38-3.30], for ≥70 age P = .94, OR: 0.69 [0.11-4.28]). The same results were obtained when FV Leiden mutation carriers were excluded (for 0-18 age group P = .95, OR: 1.15 [0.35-3.78], for ≥70 age P = .89, OR: 0.73 [0.11-4.56]). In this study, an effect on thrombosis of -426G/A polymorphism was not determined.