A case control study of deep venous thrombosis in relation to factor V G1691A (Leiden) and A4070G (HR2 Haplotype) polymorphisms

Association Between Thrombophilic Gene Mutations and the Risk of Vascular Access Thrombosis in Hemodialysis Patients

The cause of thrombosis in hemodialysis vascular access is considered to be of a multifactorial nature, including stenosis of the venous or arterial connection. Therefore, identification of relevant thrombotic risk factors could lead to an improved antithrombotic therapy. This case control study was performed to evaluate the relationship between Factor V (G1691A and A4070G) and Factor II polymorphisms and vascular access thrombosis in hemodialysis patients. One hundred and twenty-one patients undergoing dialysis were selected as subjects. This sample was divided into two groups; a case group of 60 patients who had sustained one or more thrombotic events that resulted in vascular access failure and a control group of 61 patients, who never had a thrombotic occlusion of a functioning permanent dialysis access. Our data demonstrated a significantly increased risk of vascular access thrombosis in carriers of the mutant FV (G1691A and A4070G) polymorphisms (P < 0.05).Further studies on a large-scale population and other genetic variants will be needed to find candidate genes for vascular access thrombosis in hemodialysis patients.

Polymorphisms in thrombophilic genes are associated with deep venous thromboembolism in an Iranian population

It has been revealed that the inherited thrombophilia increases the risk of thrombosis in the venous system. To study the association of factor V G1691A, factor V HR2 (4070A/G), prothrombin G20210A, and PAI-1 (- 675 I/D, 5G/4G) polymorphisms with deep venous thromboembolism (DVT), these polymorphisms were investigated. A total of 193 patients who presented clinical symptoms of deep venous thromboembolism including 103 men and 90 women, and 500 healthy individuals without both personal and family histories of thromboembolic disorders including 275 men and 225 women were recruited into the study. Genotyping was carried out using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique. Our results showed that the genotype distribution for FV (G1691A and A4070G) and PAI-1 4G/5G polymorphisms in DVT patients were significantly higher than healthy control (P < 0.05). Also, the mutant allele frequencies for all studied polymorphisms differed significantly between the case and control groups (P < 0.05). We concluded that the prevalence of FV (G1691A and A4070G) and PAI-1 4G/5G polymorphisms increased the risk of DVT occurrence in subjects. These findings provide additional evidence to support the hypothesis that thrombophilic gene polymorphisms are involved in vascular thromboembolism.

Apolipoprotein E polymorphism is associated with lower extremity deep venous thrombosis: color-flow Doppler ultrasound evaluation

Introduction

Apolipoprotein E (apoE) is a member of apolipoprotein family, and its gene polymorphisms seem to have some impact among patients with cardiovascular disease. However, its role in the lower extremity deep venous thrombosis (LEDVT) has not been well studied. The objective of this study was to investigate the potential association between APOE gene polymorphisms and LEDVT.

Materials and methods

A hospital-based case–control study was conducted in 300 patients with LEDVT by color-flow Doppler ultrasound and 300 age- and gender-matched healthy controls. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay was applied to assess the APOE gene polymorphisms.

Results

Patients with LEDVT had a significantly higher frequency of APOE E3/E4 genotype [odds ratio (OR) =1.48, 95% confidence interval (CI) = 1.05, 2.10; P = 0.03] than healthy controls. When stratifying by family history of LEDVT, it was found that patients with positive family history of LEDVT had a significantly higher frequency of APOE E3/E4 genotype (OR =1.68, 95% CI = 1.04, 0.95; P = 2.70). When stratifying by smoking status, presence of varicose veins, type 2 diabetes mellitus and any hormone administration before, no significant differences were found in any groups.

Conclusion

Our study suggested that APOE E3/E4 genotype was associated with a higher LEDVT risk. Additional studies are needed to confirm this finding.

Epidemiology of activated protein C resistance and factor v leiden mutation in the mediterranean region

Venous thromboembolic disorders (VTE) are serious disorders with high morbidity and mortality rates. Many genetic and acquired risk factors were identified to cause VTE. The most common genetic risk factor is Factor V Leiden mutation (FVL). FVL was found in high percentage of populations of Caucasian origin but was almost absent in non-Caucasians. It was also reported in populations living in North Africa and the Middle East. This review article briefly explains FVL and how it causes VTE, the distribution of FVL worldwide, and then it elaborates on the epidemiology of FVL in the Mediterranean Region and how this brought speculations that FVL might have originated in the Eastern Mediterranean area.