Factor V Leiden mutation in Sneddon syndrome

Sneddon syndrome (SNS) is characterized by the association of ischaemic cerebrovascular events and widespread livedo racemosa. Its pathophysiology is still controversial. The aim of this study was to evaluate the prevalence of factor V Leiden mutation in consecutive patients referred for SNS according to antiphospholipid antibodies (aPL) status. Fifty-three Caucasian patients were enrolled from 1996 to 2001. Diagnosis of SNS was based on the presence of a widespread livedo racemosa and at least one clinical neurologic ischaemic event. The following investigations were performed: detection of antithrombin III, protein C and protein S deficiency, lupus anticoagulant, anticardiolipin and anti-beta2 glycoprotein I antibodies, biologic false-positive test for syphilis, and factor V Leiden mutation by direct genomic analysis. Fisher's test and t-test were used for statistics. Detection of aPL on multiple determinations was negative in 31 patients (group 1) and positive in 22 patients (group 2). Factor V Leiden mutation was detected in six patients (11.3%), heterozygous in all. The frequency of this mutation was statistically higher in group 1 (6/31, 19.3%) than in group 2 (0/22; P = 0.035). Within aPL-negative SNS, the comparison of patients with versus without factor V Leiden mutation showed no difference for clinical data or familial history of thrombosis. A high prevalence of heterozygous factor V mutation was found in aPL-negative patients with SNS. This finding adds further arguments to consider SNS as a heterogeneous entity.     

Factor V Leiden mutation and type 1 diabetes mellitus.

Diabetes mellitus is considered to cause a tendency for arterial thrombosis. Recent studies addressed the association between venous and arterial disease. Resistance to activated protein C is one of the most common causes of venous thrombosis and linked to a single point mutation in the factor V gene, designated as factor V Leiden mutation. There is little information regarding the status of factor V Leiden mutation in type 1 diabetes. The aim of this study is to evaluate association among activated protein C sensitivity ratio, factor V Leiden mutation, and type 1 diabetes taking into account metabolic control, lipids and diabetic complications. The study population consisted of 47 healthy subjects (27.9 +/- 1.2 years) and 48 type 1 diabetic patients (27.9 +/- 1.1 years). Activated protein C sensitivity ratio was measured by activated partial thromboplastin time based assay. The presence of factor V Leiden mutation was determined by amplifying the fragments encompassing gene mutation by PCR. Mean normalized activated protein C sensitivity ratio values and prevalence of heterozygous factor V Leiden mutation were not significantly different between groups (1.08 +/- 0.03 and 6.3% in healthy subjects; 1.01 +/- 0.03 and 6.4% in type 1 diabetic patients, respectively). The activated protein C sensitivity ratio and factor V Leiden mutation were not found to be linked with metabolic control parameters, lipids and diabetic complications in type 1 diabetic patients. There was no association among factor V Leiden mutation, activated protein C sensitivity ratio and type 1 diabetes, metabolic control parameters as well as complications of diabetes. Although the propensity to thrombosis is increased in individuals with type 1 diabetes, activated protein C sensitivity ratio and factor V Leiden mutation do not appear to be significant determinants.     

Factor V Leiden and prothrombin gene mutation in inflammatory bowel disease in a Mediterranean area.

BACKGROUND: Thromboembolism has been reported to be associated with inflammatory bowel disease. AIM: To evaluate the association of factor V Leiden and prothrombin gene mutation with inflammatory bowel disease in a population of patients with thromboembolic events and inflammatory bowel disease and in a control population of patients with inflammatory bowel disease without thromboembolic events. PATIENTS AND METHODS: A series of 18 patients with inflammatory bowel disease and a history of arterial or venous thrombosis and 45 patients with inflammatory bowel disease without thromboembolic events were evaluated for the presence of factor V Leiden and prothrombin gene mutation. Frequency of gene mutation was compared with its occurrence in 100 healthy controls. RESULTS: One patient with inflammatory bowel disease without thromboembolic events was heterozygous for factor V Leiden mutation. whereas no patient with a thromboembolic event had factor V Leiden mutation. No patients (either cases or controls) had prothrombin gene mutation. In the healthy population the frequency of factor V Leiden and prothrombin mutation was 5% and 2%, respectively. CONCLUSIONS: Data emerging from the present study do not support any role of factor V Leiden and prothrombin gene mutation as the cause of thromboembolism in inflammatory bowel disease.     

Factor V Leiden and prothrombin gene mutation in inflammatory bowel disease in Mediterranean area

Background. Thromboembolism has been reported to be associated with inflammatory bowel disease.Aim. To evaluate the association of factor V Leiden and prothrombin gene mutation with inflammatory bowel disease in a population of patients with thromboembolic events and inflammatory bowel disease and in a control population of patients with inflammatory bowel disease without thromboembolic events.Patients and methods. A series of 18 patients with inflammatory bowel disease and a history of arterial or venous thrombosis and 45 patients with inflammatory bowel disease without thromboembolic events were evaluated for the presence of factor V Leiden and prothrombin gene mutation. Frequency of gene mutation was compared with its occurrence in 100 healthy controls.Results. One patient with inflammatory bowel disease without thromboembolic events was heterozygous for factor V Leiden mutation. whereas no patient with a thromboembolic event had factor V Leiden mutation. No patients (either cases or controls) had prothrombin gene mutation. In the healthy population the frequency of factor V Leiden and prothrombin mutation was 5% and 2%, respectively.Conclusions. Data emerging from the present study do not support any role of factor V Leiden and prothrombin gene mutation as the cause of thromboembolism in inflammatory bowel disease.     

Factor V Leiden mutation in venous thrombosis in southeast Turkey

Venous thrombosis (VT) is a common disease, with an annual incidence in the general population of approximately 1 per 1,000. Factor V Leiden mutation (G1691A) (FVL) is the most common risk factor in venous thrombosis. The prevalence of FVL for thrombosis varies greatly in different regions of the world. FVL mutation has been identified both by conventional method and fluorescence resonance energy transfer (FRET) with the LightCycler. Sixty-one patients with VT, different in age and sex, were consecutively entered into this study to assess the prevalence of FVL in VT in southeast Turkey. FVL mutation was found in 24.6% (15/61). Fourteen individuals were heterozygous and 1 homozygous, a rate of 22.9% and 1.6%, respectively. In conclusion, the authors suggest that FVL mutation is common in patients with venous thrombosis in southeast Turkey.     

Factor V Leiden mutation and other thrombophilia markers in childhood ischemic stroke.

The aim of this study was to evaluate the association between ischemic childhood stroke and thrombophilia. The prevalence of thrombophilia risk factors in 30 unrelated children with ischemic stroke were compared with 33 age-matched control subjects. Patients and control group were tested for the presence of activated protein C (APC) resistance, antiphospholipid antibodies (APLA), increased factor VIII levels, and for the deficiency of protein C (PC), protein S (PS), and antithrombin. When APCR was detected in patients or in controls, factor V Leiden (FVL) mutation was also tested. Seventeen of 30 patients (56.6%) had at least one thrombophilia marker compared with only 5 of 33 control subjects (15.1%). Three children with ischemic stroke (10%) were affected with a combination of two or more thrombophilia markers whereas none of the children in the control group had a combination of risk factors. Seven of 30 children with ischemic stroke (23.3%) and one of 33 control subjects (3.03%) had APC resistance and in all of them FVL mutation were found. The prevalence of FVL mutation was higher among pediatric stroke patients than among control subjects (p < 0.05). None of the patients but one child from the control group (3.03%) had PS deficiency. Antithrombin and PC deficiencies and the presence of APLA and increased factor VIII levels were more frequent in the pediatric stroke patients than in controls but the difference was not statistically significant (p > 0.05). These data confirm that stroke in children is commonly associated with a combination of multiple risk factors and especially the prevalence of FVL mutation is increased in children with ischemic stroke compared with control subjects.     

Factor V Leiden mutation and the risk of venous thromboembolism in pregnant women.

BACKGROUND AND OBJECTIVES: In this retrospective, single center, cohort study we assessed the risk of pregnancy-related venous thromboembolism (VTE) in women belonging to a large number of families identified because of a symptomatic proband with single identified factor V Leiden mutation. DESIGN AND METHODS: Female family members who had experienced at least one full-term pregnancy were enrolled in the study. Two hundred and seventy pregnancies occurred in 105 carriers and 215 pregnancies in 81 non-carriers of factor V Leiden mutation. RESULTS: The frequency of VTE was 6.4% for heterozygous, 16.7% for homozygous, 20% for double heterozygous carriers of thrombophilic defects, and 1.2% for non-carriers. The majority of VTE events related to pregnancy occurred in the post-partum period. The relative risks of developing pregnancy-related VTE in women who were carriers of heterozygous and homozygous (or combined heterozygous) factor V Leiden mutation as compared to non-carriers were 5.3 (95% CI, 0.6 to 43.9) and 15.4 (95% CI, 1.4 to 164), respectively. INTERPRETATION AND CONCLUSIONS: Factor V Leiden mutation is a risk factor for pregnancy-related VTE, especially in its homozygous form and in combination with other thrombophilic abnormalities. Screening of families with this mutation might be useful for women of fertile age, as they may take advantage from thromboprophylaxis during pregnancy and the post-partum period.     

Factor V Leiden mutation in Turkish patients with homozygous cystathionine beta-synthase deficiency

Venous and arterial thromboembolism can occur in patients with homocystinuria. Resistance to activated protein C, which is caused by a single point mutation in the gene for factor V, renders an individual at risk for thrombosis. It has been suggested that coexistence of hereditary homocystinuria and factor V Leiden mutation might jointly play a role in the development of thrombosis. We analysed six patients with homocystinuria due to cystathionine -synthase deficiency for factor V Leiden and prothrombin G20210A mutations. Only one patient was found to have the factor V Leiden mutation in homozygous form and this patient had suffered from severe thrombosis. One patient was found to be heterozygous with no documented thrombosis. None of the patients had prothrombin G20210A mutation. We stress the necessity for screening for known thrombophilic risk factors in patients with cystathonine -synthase deficiency. The coexistence of the factor V Leiden mutation can cause severe thrombotic events in patients with homocystinuria.     

凝血因子V莱顿突变对载脂蛋白E基因敲除小鼠动脉粥样硬化的影响

目的 评价凝血因子V莱顿突变(FvL)对动脉粥样硬化的影响.方法 建立FvL与载脂蛋白E(ApoE)基因复合突变小鼠,并分析其动脉粥样硬化形成和纤维蛋白沉积情况.结果 小鼠52周龄时,FvL纯合子ApoE-/-(FvQ/Q APOE-/-)小鼠动脉粥样硬化范围明显大于野生型ApoE-/-(Fv+/+ApoE-/-),小鼠,FvQ/Q ApoE-/-比Fv+/+ApoE-/-为(5.0±1.1)%比(2.2±0.4)%,P＜0.005;FvL杂合子ApoE-/-(FvQ/+ApoE-/-)小鼠动脉粥样硬化范围位于FvQ/Q ApoE-/-小鼠和Fv+/+ApoE-/-小鼠之间,与两者的差异均无统计学意义,FvQ/+ApoE-/-比FvQ/QApoE-/-为(2.9±0.6)%比(5.0.±1.1)%,P＞0.05,FvQ/+ApoE-/-比Fv+/+ApoE-/-为(2.9±0.6)%比(2.2±0.4)%,P＞0.05.FvQ/Q ApoE-/-小鼠动脉粥样硬化斑块内的纤维蛋白沉积同样明显高于Fv+/+ApoE-/-小鼠,FvQ/Q ApoE-/-比Fv+/+ApoE-/-为(3.4±0.5)%比(1.8±0.4)%,P＜0.05.结论 FvL纯合子明显增加ApoE-/-小鼠动脉粥样硬化程度及动脉粥样硬化斑块内的纤维蛋白沉积,提示FvL突变可能是重要的促进动脉粥样硬化形成的因素,临床上患者出现严重的动脉粥样硬化可能合并FvL遗传基因缺陷.