Coexistence of factor V G1691A and factor II G20210A gene mutations in a thrombotic family is associated with recurrence and early onset of venous thrombosis.

Two G-to-A mutations at positions 1691 of the factor V (FV) gene and 20210 of the prothrombin (FII) gene have been associated with an increased risk of venous thromboembolism. We report a thrombosis-prone family in which one subject--the propositus who exhibited combined heterozygous FV G1691A and FII G20210A mutations--showed spontaneous and early clinical onset (at 23 years), recurrences of deep-vein thrombosis and pulmonary embolism. His asymptomatic father carried the FII G20210A substitution and his mother, characterized by an isolated thrombotic episode on occasion of surgery (at 48 years), carried the FV G1691A substitution. In the maternal lineage, one of the propositus' uncles had thrombosis on occasion of a bone fracture (at 65 years) despite the absence of known prothrombotic defects. A sister of the propositus carried the FII G20210A and the brother the FV G1691A mutation. They have been asymptomatic until now. The propositus' two children, 20 and 16 years old, both carry the FV G1691A substitution and have been asymptomatic until now. The plasma levels of FII were higher in carriers of the FII G20210A allele if compared with noncarriers, and the activated protein C resistance phenotype, associated with the FV Leiden mutation, showed a complete correlation with the FV G1691A mutation. Despite the very limited number of thrombotic cases involved in this survey, which does not allow statistically sound conclusions, the data obtained from this family suggest that the synergy of inherited factors and transient risk conditions could play a key role in the occurrence of thrombotic accidents.     

Analysis of polymorphisms Leiden Factor V G1691A and prothrombin G20210A as risk factors for acute myocardial infarction

Thrombotic risk increases in elderly, therefore, the understanding of the genetic predisposition of hypercoagulability could make the difference in the prevention of venous and/or arterial thrombotic events. Laboratory evaluation of hyperfibrinogenemia, increased Factor VII levels, antiphospholipid antibodies presence and hyperhomocysteinemia are considered to have a consistent high predictivity for arterial thrombophilic diseases. Anyway, a large debate exists on the validity of testing Leiden Factor V (FV) G1691A and/or prothrombin (FII) G20210A polymorphisms in patients affected by arterial thrombotic diseases, despite of the several observations described. Here we report data strongly suggesting that at least the FII G20210A polymorphism might be considered an important risk factor for acute myocardial infarction in aged patients (55–80 years old). On the other hand, in spite of a not different genotypic and allelic distribution for the Leiden FV G1691A mutation, the presence of one or both the two polymorphisms is significantly higher among cases than in controls. In conclusion, our data suggest that FII G20210A and/or Leiden FV might be involved as risk factor for arterial disorders in about 5% of old subjects, justifying the opportunity of a genetic screening and an eventual preventive treatment, in particular in old subjects in which other and major risk factors, as hypertension and atherosclerosis, are detected.     

The impact of heterozygosity for the factor V Leiden and factor II G20210A mutations on the risk of thrombosis in Greek patients.

AIM: There is growing evidence that a number of genetic risk factors predispose independently to venous thrombosis and the coexistence of defective genes is involved in the manifestation and recurrence of thrombotic events. The goal of this study was to examine the efficiency of the selection criteria for performing a genetic test for the factor V G1691A (Leiden) and factor II G20210A mutations. METHODS: Blood samples were drawn from 119 patients referred to us by their physicians. FV and prothrombin (FII) mutations were detected by polymerase chain reaction (PCR) followed by digestion with restriction endonucleases MnlI (FV), HindIII and MspI (FII). RESULTS: Patient carrier frequencies were 16.8% and 10.08% for FV Leiden and FII G20210A, respectively. Heterozygosity for FII G20210A was observed in 10.0% of FV Leiden carriers whereas FV Leiden homozygosity was noted in 1.68% of the patients. Genotype frequencies were in conformity with Hardy-Weinberg equilibrium by the chi square goodness of fit test. CONCLUSION: The obtained data provided a substantial genetic explanation of the thrombotic phenotype in approximately 25% of the patients and thus the physicians selection criteria were sufficient for genetic testing. Furthermore, coinheritance of both genetic defects were significantly associated with increased thrombosis risk and that of recurrent thrombosis.     

High prevalence of three prothrombotic polymorphisms among Palestinians: factor V G1691A, factor II G20210A and methylenetetrahydrofolate reductase C677T

Factor V leiden G1691A/R506Q (FVL), prothrombin G20210A (FII) and methylenetetrahydrofolate reductase (MTHFR) C677T are related genetic risk factors for venous thromboembolism. Analysis for those mutations is increasingly being performed on patients exhibiting hypercoagulability. The objective of this study was to determine the prevalence of FVL, FII-G20210A and MTHFR-C677T polymorphisms and their coexistence among apparently healthy Palestinians. After institutional approval, 303 apparently healthy students from An-Najah University representative to North and South regions of West Bank with no previous history of cardiovascular diseases participated in this study. A uniform questionnaire was used to collect relevant information through personal interview with the subjects. The collected information included gender, age, smoking habits, weight and height, diseases such as diabetes, cardiovascular and family history of CVD. The frequencies of allelic distribution of the three prothrombotic polymorphisms factor V G1691A/R506Q), prothrombin G2010A, and MTHFR-C677T were 0.114, 0.050 and 0.071, respectively. The prevalence of the three thrombotic polymorphisms (FVL, FII G20210A and MTHFR-C677T) were 20.1, 9.1 and 13.8?%, respectively. Statistical analysis for factor V leiden showed no significant association between place of residence (P value?=?0.953) and gender (P value?>0.082). The data presented in this study showed the highest prevalence of FVL among healthy Palestinians compared to other populations and this important finding should be followed in terms of clinical significance.     

Genetic polymorphisms associated with acute pulmonary embolism and deep venous thrombosis.

Frequently an inherited predisposition to thrombosis remains clinically silent until an additional environmental factor intervenes. The present study aimed to assess distribution of inherited risk factors of venous thrombosis in patients with venous thromboembolism (VTE). The prevalences of factor V Leiden (FV Leiden), prothrombin factor II G20210A (FII G20210A), C677T and A1298C of methylenetetrahydrofolate reductase (MTHFR) mutations were studied in 149 VTE patients and 100 controls. The following key risks were established: previous deep venous thrombosis or pulmonary embolism (23.5%), bed rest (34.2%), immobilisation of lower limb (10.1%), hospitalisation (30.9%) and obesity (28.9%). In 29 (19%) patients and in three (3%) controls FV Leiden was found. A significant association between VTE and FV Leiden was established. There were six (4%) carriers of the FII G20210A among VTE patients and one in the controls. No associations between VTE and MTHFR polymorphisms (C677T, A1298C) were found. In three of 149 patients both FV Leiden and FII G20210A polymorphisms were observed. The mean protein C activity was slightly, though nonsignificantly, smaller in VTE patients. In conclusion, there was a positive association between venous thromboembolism and factor V Leiden. Only a weak trend favouring a relationship between prothrombin factor II G20210A and venous thrombolism was present. No associations between common polymorphisms of methylenetetrahydrofolate reductase and venous thromboembolism were found.     

Inherited thrombophilic risk factors and venous thromboembolism: distinct role in peripheral deep venous thrombosis and pulmonary embolism

STUDY OBJECTIVES: To investigate whether the FII A(20210) mutation is associated with isolated pulmonary embolism (PE). DESIGN: Case-control study. SETTING: Five thrombosis centers in southern Italy. PATIENTS: Six hundred forty-seven consecutive referred patients with objectively documented venous thrombosis and 1,329 control subjects. Measurements and results: Medical histories were collected. The G-to-A transition at nucleotide 1691 within the factor V gene (FV Leiden) and the G-to-A transition at nucleotide position 20210 within the prothrombin gene locus (FII A(20210)), levels of anticoagulant factors, and levels of antiphospholipid antibodies were determined by standard techniques. Patients with deep venous thrombosis (DVT) of the lower extremities (n = 346) or with additional PEs (n = 175) showed similar prevalences of FV Leiden mutation (24.3% and 16.6%, respectively) and FII A(20210) mutation (14.2% and 12.6%, respectively), and similar deficiencies of natural anticoagulants (4.9% and 2.3%, respectively). In both groups, the frequencies of FV Leiden and/or FII A(20210) mutation were higher than those observed among 1,329 apparently healthy control subjects (4.8% and 4.4%, respectively; p < 0.0001). Among patients with isolated PE (n = 126), prevalences of FV Leiden (7.1%) and FII A(20210) mutation (8.7%) were similar to those of control subjects. Inherited thrombophilic abnormalities were less frequent among patients with PE only (15.6%) than among those with DVT only (37.0%; p < 0.001) or whose conditions were complicated by PE (28. 0%; p = 0.020). Adjusting for age and sex, FV Leiden mutation, FII A(20210) mutation, or both mutations were associated with DVT with PE (FV Leiden mutation: odds ratio [OR], 3.0; 95% confidence interval [CI], 1.6 to 5.5; FII A(20210) mutation: OR, 2.6; 95% CI, 1. 3 to 5.2; and both mutations: OR, 82.1; 95% CI, 7.5 to 901.2) or without PE (FV Leiden mutation: OR, 6.1; 95% CI, 4.0 to 9.3; FII A(20210) mutation: OR, 2.8; 95% CI, 1.7 to 4.8; and both mutations: OR, 167.5; 95% CI, 21.6 to 1,297.7), but not with isolated PE (FV Leiden mutation: OR, 1.2; 95% CI, 0.5 to 2.8; FII A(20210) mutation: OR, 1.2; 95% CI, 0.5 to 3.1; and both mutations: OR, 22.1; 95% CI, 1. 3 to 370.2). CONCLUSIONS: FII A(20210) mutation is associated with DVT in the lower extremities alone or when complicated by PE, but it is not associated with isolated PE.     

Prothrombin G20210A gene mutation and further prothrombotic risk factors in childhood thrombophilia.

Risk factors for venous thrombosis in adults are the prothrombin G20210A and the factor V (FV) G1691A mutations and hereditary deficiencies of protein C, protein S and antithrombin. However, data are limited on the relevance of these risk factors for thrombosis in children and adolescents. We therefore investigated 261 patients aged 0 to 18 (median 5.7 years, 48% male) with venous thrombosis and controls (n=370) for the presence of prothrombotic risk factors including the prothrombin G20210A mutation. The following frequencies of hereditary risk factors (patients versus controls), odds ratios (OR) and 95% confidence intervals (CI), or results of Fisher's exact test, respectively, were found: prothrombin G20210A, 4.2% versus 1.1%, OR/CI 4.1/1.3 to 12.8; FV G1691A, 31.8% versus 4. 1%, OR/CI 11.0/6.2 to 19.7; protein C deficiency, 9.2% versus 0.8%, OR/CI 12.4/3.7 to 41.6, protein S deficiency, 5.7% versus 0.8%, OR/CI 7.5/2.1 to 26.0; antithrombin deficiency in 3.4% in the patients, but not in the controls, P=0.0003. The prothrombin mutation was combined with the heterozygous FV G1691A mutation (2. 3%) or protein C deficiency (0.3%) in the patients, but not in the controls (prothrombin and FV mutation, P=0.0048; prothrombin and protein C deficiency, not significant). The carrier frequencies and ORs of all hereditary risk factors showed a non-significant trend toward higher prevalences in patients suffering spontaneous thrombosis, compared with those with an additional underlying disease. In conclusion, the prothrombin G20210A and the FV G1691A mutation, deficiencies of protein C, protein S, and antithrombin are important risk factors for venous thrombosis during childhood and adolescence.     

Prevalence of factor V Leiden (G1691A) and prothrombin (G20210A) among Kurdish population from Western Iran

BACKGROUND: The mutation in factor V (FV) G1691A, known as factor V Leiden, and prothrombin (FII) gene G20210A are the two most prevalent causes of inherited thrombophilia. The present study reports the prevalence of factor V Leiden and the prothrombin G20210A gene mutations among healthy individuals of Kurdish ethnic background in Western Iran. METHODS: Four hundred thirty-four healthy unrelated individuals, 255 male and 179 female, with a mean age of 28.7+/-15.5 from the Kermanshah Province of Iran were studied for prothrombin G20210A mutation. The factor V Leiden mutation was studied in 404 healthy individuals, of whom 232 were male and 172 were female. The factor V Leiden and prothrombin G20210A were detected by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method using Mnl I and Hind III restriction enzymes, respectively. RESULTS: Among 434 individuals studied for prothrombin G20210A mutation seven carried this mutation as heterozygous (four female subjects and three male), giving a prevalence of 1.6% [95% confidence intervals (CI) 0.5-2.7) and an allele frequency of 0.8%. No homozygous prothrombin 20210AA was found. Factor V G1691A mutation was detected as heterozygous in 11 of 404 healthy individuals (five female and six male) and as homozygous in one male indicating a prevalence of 2.97% (95% CI 1.3-4.6) and allele frequency of 1.6%. CONCLUSIONS: Our results indicated that the factor V Leiden and prothrombin G20210A mutations are not rare among populations of Western Iran and that the relationship between venous thrombophilia and these mutations have to be further studied in Western Iran population, which, in turn, may suggest a causal effect.     

Molecular analysis of factor V Leiden, factor V Hong Kong, factor II G20210A, methylenetetrahydrofolate reductase C677T, and A1298C mutations related to Turkish thrombosis patients.

Inherited gene disorders related to the hemostatic system have been documented as risk factors for thrombosis. The roles of factor V Hong Kong (FV Hong Kong), factor V Leiden (FV Leiden), factor II G20210A (FII G20210A), methylenetetrahydrofolate reductase (MTHFR) C677T, and MTHFR A1298C mutations in Turkish patients with thrombosis (270 patients) compared with healthy controls (114 subjects) were evaluated. Polymerase chain reaction-based restriction enzyme analysis was carried out to screen these mutations, and single-strand conformation analysis was established to identify variations using the primers selected for restriction enzyme analysis studies. As a result, a significant relationship was determined among FV Leiden, FII G20210A, and thrombosis. The FV Hong Kong mutation was observed in only 2 patients with pulmonary vein thrombosis who are FV Leiden/FV Hong Kong compound heterozygous for FV gene. MTHFR C677T and A1298C were equally distributed in the patient group compared with the control group. All named mutations were also identified with single-strand conformation analysis, but a new variant/polymorphism during studies was not found. Because some inherited abnormalities are associated with thromboembolic disorders, determining the mutations and gene-to-gene interactions in patients with thrombosis history has a great impact on diagnosis and treatment of these diseases.     

Coexistence of prothrombic risk factors and its relation to left ventricular thrombus in acute myocardial infarction

OBJECTIVE: Within the last few years a number of thrombophilic mutations have been identified. Pre-symptomatic testing for these established genetic risk factors identifies individuals predisposed to a disease and often allows to select suitable prophylactic interventions in time. We investigated whether or not the prothrombin G20210A allele, the factor V Leiden G1691A, and MTHFR C677T allele are risk factors for left ventricular thrombus (LV) in patients with myocardial infarction (AMI) or not. METHODS AND RESULTS: We analysed clinical, echocardiographic and biochemical data in 183 consecutive patients (aged 58 +/- 12 years; 34 women) with a first anterior acute myocardial infarction. Two-dimensional echocardiographic examination was performed on days 1, 3, 7, 15, and 30. LV thrombi were detected in 42 (23%) of the 183 patients with acute myocardial infarction. We have used multiplex assays based on PCR and DNA hybridization in microtitre plates for the simultaneous analysis of three mutations (FV Leiden G1691A, prothrombin G20210A, and MTHFR C677T). No significant differences in allele frequencies of FV Leiden G1691A (9.5% vs. 8.5%, p = 0.75), prothrombin G20210A (9.5% vs 7.1%, p = 0.74) and MTHFR C677T (47.6% vs. 50.3%, p = 0.74) were found in patients with LV thrombus when compared with those without LV thrombus. No significant differences in haemostatic factor levels were found in patients with LV thrombus when compared with those without LV thrombus. CONCLUSION: FV Leiden, prothrombin 20210 variant, and MTHFR mutation are no risk factors for left ventricular thrombus in patients with myocardial infarction.The presence of multiple mutations did not influence the development and outcome of LV thrombus in patients with myocardial infarction     

Effects of the factor V G1691A mutation and the factor II G20210A variant on the clinical expression of severe hemophilia A in children--results of a multicenter studys

The present multicenter cohort study of 107 pediatric PUPs was performed to determine whether the concomitant inheritance of the factor (F) V G1691A or the F II G20210A mutation influences the clinical expression of severe hemophilia A (HA). Carriers of the FV and FII mutations had a significantly lower annual bleeding frequency (ABF) than non-carriers (p=0.012). Joint damage (Pettersson score) was significantly less severe in patients with thrombophilia (p=0.022). A protective effect of thrombophilic risk factors was shown for ABF (OR [CIs]: 0.7[0.5-0.9]; p=0.02) and the severity of the hemophilic arthropathy (OR [CIs]: 0.06[0.01-0.3]; p=0.0009).     

Association between adverse pregnancy outcomes and maternal factor V G1691A (Leiden) and prothrombin G20210A genotypes in women with a history of recurrent idiopathic miscarriages

Thrombophilia was implicated in the development of pregnancy complications, including recurrent idiopathic pregnancy loss, and is aggravated in women who are carriers of factor V G1691A (FV Leiden) and prothrombin (PRT) G20210A single-nucleotide polymorphisms (SNPs). Previous studies examined the role of FV-Leiden and PRT G20210A in recurrent pregnancy loss with conflicting results. Here we examined the prevalence of FV Leiden and PRT G20210A SNPs, in 200 women with 3 or more consecutive early (n = 87), late (n = 41), or early-late (n = 72) recurrent pregnancy losses, and 200 age-matched fertile parous control women. APC resistance (APCR) was detected functionally (measuring the activated clotting time triggered by activated factor X in presence of a fixed amount of purified APC), and FV-Leiden and PRT G20210A genotypes were assessed by PCR. The frequency of the mutant FV (0.1400 vs. 0.0276; P < 0.001) but not PRT 20210 (0.0100 vs. 0.0225; P = 0.159) allele was higher in patients than controls, respectively. APC resistance with factor V Leiden was seen in 27% of patients compared to 11.5% of controls, while APC resistance without factor V Leiden was seen in 12.5% of patients compared to 9.5% of controls. Regression analysis demonstrated that the significant predictors for early abortion was FV Leiden; those for late abortion were oral contraceptive, APCR, and FV Leiden; and predictors for early-late abortions were oral contraceptives, obesity, FV Leiden, and smoking. APC resistance and FV Leiden, as well as combination of both, are common thrombotic defects seen in women with idiopathic recurrent pregnancy loss, thus testing for these is recommended in women who have experienced recurrent miscarriages.     

Lipoprotein (a) and genetic polymorphisms of clotting factor V, prothrombin, and methylenetetrahydrofolate reductase are risk factors of spontaneous ischemic stroke in childhood

Ischemic stroke is a rare event in childhood. In approximately one third of cases no obvious underlying cause or disorder can be detected. We investigated the importance of genetic risk factors of venous thromboembolism in childhood or stroke in adulthood as risk factors for spontaneous ischemic stroke in children. One hundred forty-eight Caucasian infants and children (aged 0.5 to 16 years) with stroke and 296 age-matched controls from the same geographic areas as the patients were analyzed for increased lipoprotein (a) [Lp(a)] levels >30 mg/dL; for the presence of the factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, and the TT677 genotype of methylenetetrahydrofolate reductase (MTHFR); and deficiencies of protein C, protein S, and antithrombin. The following frequencies (patients v controls), odds ratios (ORs), and confidence intervals (CIs) of single risk factors were found: Lp(a) >30 mg/dL (26.4% v 4.7%; OR/CI, 7.2/3.8 to 13.8; P <.0001), FV G1691A (20.2% v 4%; OR/CI, 6/2.97 to 12.1; P <.0001), protein C deficiency (6% v 0.67%; OR/CI, 9.5/2 to 44.6; P =.001), PT G20210A (6% v 1.3%; OR/CI, 4.7/1.4 to 15.6; P =.01), and the MTHFR TT677 genotype (23.6% v 10.4%; OR/CI, 2.4/1.53 to 4.5; P <.0001). A combination of the heterozygous FV G1691A mutation with increased Lp(a) (n = 11) or the MTHFR TT677 genotype (n = 5) was found in 10. 8% of cases, but only 0.3% of controls (OR/CI, 35.75/4.7 to 272; P <. 0001). Increased Lp (a) levels, the FV G1691A mutation, protein C deficiency, the prothrombin G20210A variant, and the MTHFR TT677 are important risk factors for spontaneous ischemic stroke in childhood.     

Abdominal venous thrombosis in neonates and infants: role of prothrombotic risk factors - a multicentre case-control study. For the Childhood Thrombophilia Study Group

The factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, the methylenetetrahydrofolate reductase (MTHFR) T677T genotype, together with fasting homocysteine (HCY) concentration, lipoprotein (Lp)(a), anti-thrombin (AT), protein C (PC), protein S (PS) and anti-cardiolipin antibodies were investigated in 65 consecutively recruited infants (neonate to < 12 months) with renal venous thrombosis (RVT; n = 31), portal vein thrombosis (PVT; n = 24) or hepatic vein thrombosis (HVT n = 10), and 100 age- and sex-matched healthy controls. FV G1691A was found in 14 babies (heterozygous: RVT n = 9, PVT n = 4; homozygous HVT n = 1) and five controls, the MTHFR TT677 genotype together with increased HCY in four infants with thrombosis (RVT n = 2; PVT n = 1; HVT n = 1) compared with one control, and the PT G20210A variant was present in one control only. PC type I deficiency was diagnosed in three patients (RVT n = 2; PVT n = 1) and AT deficiency in two patients (RVT n = 1; PVT n = 1). Three neonates with spontaneous thrombosis showed FV G1691A combined with Lp(a) and the FV G1691A was combined with the PT G20210A genotype in two infants. Additional triggering factors were reported in 27 patients (41.5%). The overall odds ratios (ORs) and 95% confidence intervals (CIs) with respect to the different thrombosis locations were: RVT (OR/CI: 10.9/3.85-31.1; P < 0.0001), PVT (5.47/1.7-17.6; P < 0.0007) and HVT (3.3/0.58-18.7; P = 0.18). The data presented here suggest that genetic prothrombotic risk factors also play an important role in abdominal venous thrombosis during infancy.     

The importance of thrombotic risk factors in the development of idiopathic sudden hearing loss

Impaired cochlear blood circulation has been suggested to cause sudden hearing loss. In this study, the role of factor V 1691 G-A (FV 1691 G-A), prothrombin 20210 G-A (PT 20210 G-A), methylene tetrahydrofolate reductase 677 C-T (MTHFR 677 C-T), factor V 4070 A-G (FV 4070 A-G), endothelial cell protein C receptor (EPCR) gene 23-bp insertion, and plasminogen activator inhibitor-1 (PAI-1) 4G/5G mutation was assessed. Fifty-three patients with idiopathic sudden sensorineural hearing loss and 80 individuals comprising the control group were included in this study. The frequency for FV 1691 A was 6.2% in the patient group and 3.7% in the control group, PT 20210 G-A was 1.2% in the patient group and 1.9% in the control group, and FV 4070 A-G was 7.5% in the patient group and 11.3% in the control group. The frequency of MTHFR 677 C-T was significantly higher in the patient group than in the control group, with a P value of .03. PAI-1-675 4G/5G polymorphism was found to be 71.2% and 69.8%, in the control group and the patient group, respectively. The EPCR 23-bp insertion was 0% in the control group and was found in 3 patients (3.7%), which needs further study.     

Factor V (His 1299 Arg) in young Turkish patients with cerebral infarct

Inherited gene defects related to the coagulation system have been reported as risk factors for stroke. Recently, a genetic component in the factor V (FV) gene that contributes to activated protein C resistance both in the presence and absence of FV 1691 G-->A was reported. This highly conserved FV gene haplotype was marked as R2 polymorphism, an A to G alteration at position 4070 in exon 13 that predicts the His 1299 Arg substitutions. The aim of this study was to evaluate the role of this mutation in Turkish children with ischemic infarct. The case-control study included 48 patients with cerebral infarction; all were 18 years of age or younger (range: 10 months to 18 years). Ten (20.8%) of the 48 patients were found to carry the FV 1299 His-->Arg mutation, one being homozygous. One patient who had a combination of FV 1691 G-->A and protein C deficiency also carried the FV 4070A mutation. A homozygous FV 1299A patient had a prothrombin (PT) 20210A mutation in the heterozygous state. The cerebral infarct risk for FV 1299 was found to be 2.4 (95% confidence interval 0.9-6.8) for all groups. When underlying conditions were excluded, the incidence of FV 1299 was found to be 8/35 (22.8%), but the risk was almost the same. When two other common thrombophilic mutations (i.e. FV 1691 G-->A and PT 20210 G-->A) were excluded, the incidence of FV 4070 mutation increased to 7/21 (33.3%). The risk also increased to 3.9 (95% confidence interval 1.2-12.3).     

Effects of factor V gene G1691A, methylenetetrahydrofolate reductase gene C677T, and prothombin gene G20210A mutations on deep venous thrombogenesis in Behçet's disease

OBJECTIVE: Beh?et's disease (BD) is a multisystemic disease of unknown etiology, characterized by aphthous ulcerations and uveitis, that is common in the Turkish population. Venous involvement is observed in 25% of the cases. While superficial thrombophlebitis is the most common finding, deep venous thrombosis (DVT) follows it. Hyperactivity in the coagulation pathway, hypoactive anticoagulation mechanisms, or faulty fibrinolysis generate a tendency for thrombogenesis. Mutations of the genes involved in these pathways may cause predisposition to thrombosis. METHODS: Possible roles of methylenetetrahydrofolate reductase (MTHFR) gene C677T, factor V (FV) gene G1691A (Leiden), and prothrombin gene G20210A polymorphisms in venous thrombogenesis were evaluated in patients with BD; 100 healthy people, 30 BD patients without DVT, 30 BD patients with DVT, and 30 patients with idiopathic DVT were studied with the restriction fragment length polymorphism method for these 3 polymorphisms. The frequencies of these mutations for each group, separately and in combinations, are described. RESULTS: Among the 3 mutations, FV Leiden mutation was found to be a risk factor for DVT. An association between FV Leiden mutation and BD was likely, but FV Leiden mutation did not increase the risk for deep venous thrombogenesis in BD patients. MTHFR gene C677T mutation does not increase risk of DVT in BD either alone or combined with FV Leiden mutation. CONCLUSION: Although a thrombotic tendency is one of the major characteristics of BD, we found no association between these 3 thrombogenetic mutations and BD patients with thromboses.     

Factor V Leiden and prothrombin gene G20210A mutations in Italian patients with Behçet's disease and deep vein thrombosis

OBJECTIVE: To evaluate the frequency and type of vascular lesions and to study the association of factor V gene G1691A (Leiden) and prothrombin gene G20210A polymorphisms with venous thrombosis in Italian patients with Beh?et's disease (BD). METHODS: Included were 118 consecutive Italian BD patients followed over a 3-year period (1997-1999) who satisfied the International Study Group criteria for BD. The control group consisted of 132 healthy Italian blood donors. All BD patients and controls were genotyped by polymerase chain reaction and allele-specific restriction enzyme techniques for factor V Leiden and prothrombin gene G20210A polymorphisms. RESULTS: Vascular lesions were observed in 37 (31.4%) patients. The 2 most common lesions were subcutaneous thrombophlebitis (10.2%) and deep vein thrombosis (DVT) of the legs (22.8%). No significant demographic and clinical differences between patients with and without DVT were present. The distribution of allele and genotype frequencies of prothrombin gene G20210A and factor V Leiden polymorphisms did not differ significantly between BD patients and healthy controls. The frequencies of carriage rates of prothrombin gene G20210A and factor V Leiden polymorphisms in BD patients with and without DVT were similar. However, the frequency of 20210A allele was significantly higher in BD patients with ocular disease than in those without, particularly in the patients with posterior uveitis/retinal vasculitis. CONCLUSIONS: The frequency and types of vascular lesions in Italian BD patients were similar to those reported in studies from other countries. No association between factor V Leiden mutation and G20210A mutation in the 3'-untranslated region of the prothrombin gene with DVT was found. However, a prothrombin gene G20210A mutation may influence the development and severity of ocular involvement in BD.     

凝血酶原G20210A基因多态性与脑卒中的关系

目的　探讨凝血酶原 (FⅡ )G2 0 2 10A基因多态性与脑卒中的关系。方法　收集脑卒中患者 30 0例 (脑卒中组 )和性别、年龄相匹配的未患脑卒中的健康人或医院内其他与脑血管无关的患者 30 0例 (对照组 ) ,采用聚合酶链反应 限制性片段多态性 (PCR RFLP)方法进行 2 0 2 10G→A变异的分析。结果　FⅡ 2 0 2 10G→A变异 ,脑卒中组2 0 2 10A纯合子为 2例 ,2 0 2 10GA杂合子为 13例 ,对照组无 2 0 2 10A纯合子 ,2 0 2 10GA杂合子为 6例。脑卒中组FⅡ2 0 2 10G→A突变率为 5 % ,对照组突变率为 2 % ,结果显示两组G2 0 2 10A差异有显著性意义 (P =0 .0 0 3)。OR =3,95 %CI:1.0 6～ 4 .94。脑梗死组 2 0 2 10A纯合子为 2例 ,2 0 2 10GA杂合子 11例 ,脑出血组 2 0 2 10GA杂合子为 2例 ,无2 0 2 10A纯合子。脑梗死组FⅡ基因 2 0 2 10G→A突变率为 6 .5 % ,脑出血组突变率为 2 % ,脑梗死组 2 0 2 10A。基因频率为 3.75 % ,脑出血 2 0 2 10A基因频率为 1% ,两组差异有显著性意义 (P <0 .0 5 )。 2 0 2 10G→A突变脑梗死组与对照组比较差异有显著性意义 (P <0 .0 5 ) ,脑出血组与对照组比较差异无显著性意义 (P >0 .0 5 )。结论　FⅡ 2 0 2 10位G→A的突变与脑梗死的发生有关 ,与脑出血关系不明显。