Factor V G1691A (Leiden) and prothrombin G20210A single-nucleotide polymorphisms in type 2 diabetes mellitus

The association of the single nucleotide polymorphisms (SNPs) G1691A in coagulation factor V (FV)-Leiden and G20210A in prothrombin (PRT) genes with type 2 diabetes mellitus (T2DM) were analyzed in 112 T2DM patients (58 males, 54 females; mean age 55.24 +/- 13.5 years) and 249 healthy control subjects (118 males, 131 females; mean age 53.03 +/- 13.8 years). No association was found for FV-Leiden with T2DM, as the frequency of the G/G (82.1% vs. 85.5%), G/A (17.0% vs. 14.1%), and A/A (0.9% vs. 0.4%) genotypes was not different between patients and controls, respectively (P = 0.644). Similarly, lack of association of PRT G20210A with T2DM was seen among the population studied, and the frequency of the G/G (92.9% vs. 97.2%), G/A (6.3% vs. 2.8%), and A/A (0.9% vs. 0.0%) genotypes was similar among patients and controls, respectively (P = 0.094). Neither FV-Leiden nor PRT G20210A was associated with, and no evidence for interactions between these mutations was seen in, T2DM.     

Prevalence of factor V Leiden G1691A, MTHFR C677T, and prothrombin G20210A among Asian Indian sickle cell patients

The prevalence of factor V (FV) Leiden G1691A, prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations were investigated among 90 sickle trait, 61 sickle homozygous, 75 sickle beta thalassemia, and 15 HbSD Asian Indian sickle cell patients. In all, 297 healthy controls were evaluated to compare the polymorphism frequency. The prevalence of FV Leiden heterozygous G>A were significant in the group (P = .02), while PRT G20210A polymorphism was not seen among patients as well as controls. However, an increased frequency of the MTHFR 677 C>T genotype was seen among patients as well as controls, but this was not statistically significant (P = .13). This suggested a low impact of inherited hypercoagulability risk factors in the pathogenesis of sickle cell disease and/or its complications.     

Distinct association of factor V-Leiden and prothrombin G20210A mutations with deep venous thrombosis in Tunisia and Lebanon

Factor V G1691A (FV-Leiden) and prothrombin (PRT) G20210A single nucleotide polymorphisms (SNPs) were associated with venous thrombosis among Caucasians. We assessed the contribution of both SNPs to the genetic susceptibility of deep venous thrombosis (DVT) among Lebanese and Tunisian patients. Subjects comprised 198 DVT patients and 540 healthy controls from Lebanon and 126 Tunisian DVT patients and 197 control subjects; FV-Leiden (MnlI) and PRT G20210A (HindIII) genotyping was done by PCR-RFLP. While the prevalence of FV-Leiden mutant A allele and the G/A and A/A genotypes were significantly higher among DVT patients from Lebanon and Tunisia, the association of PRT G20210A with DVT was pronounced among Lebanese but not Tunisian patients. The prevalence of PRT G20210A mutant A allele (P < 0.001 vs. P = 181) and G/A genotype (P < 0.001 vs. P = 0.994) was significantly higher among Lebanese but not Tunisians, respectively. While FV-Leiden was a common genetic risk factor for DVT in both communities, the contribution of PRT G20210A to the genetic susceptibility of DVT differed among Lebanese and Tunisians, which underscores the need to determine prothrombotic gene polymorphisms associated with DVT among Arab and Mediterranean basin communities.     

Factor V G1691A,Prothrombin G20210A,and Methylenetetrahydrofolate Reductase [MTHFR] C677T Gene Polymorphism in Angiographically Documented Coronary Artery Disease

BACKGROUND: Single point mutations in the genes coding for factor V [G1691A; Leiden], prothrombin [PRT; G20210A], and methylenetetrahydrofolate reductase [MTHFR, C677T] were shown to be major inherited predisposing factors for venous thromboembolism. However, their contribution in the development of coronary artery disease [CAD] remains controversial. The aim of the study was to examine the association of these mutations in CAD. METHODS: A total of 96 patients with angiographically-demonstrated CAD [mean age 55.3 +/- 11.3], and 404 healthy subjects [mean age 50.7 +/- 8.9] were recruited into the study. Fasting plasma homocysteine was determined by HPLC, and genotype analysis was assessed by PCR-RFLP. RESULTS: The carrier frequency of factor V-Leiden (14.6% vs. 15.1%, p = 0.617) and PRT G20210A (3.1% vs. 3.0%; p = 0.936) were similar between patients and controls, respectively. In contrast, the frequency of the MTHFR variant C677T was 71.9% among patients compared with 45.5% in controls (p < 0.001), of which the T/T genotype was significantly higher among patients (31.3%) than controls (4.5%; p < 0.001). Significantly higher homocysteine levels were seen among T/T genotype in both groups compared to non-T/T carriers (p < 0.05), and among patients compared with controls (18.47 +/- 3.73 micromol/L vs. 16.28 +/- 4.16 micromol/L). In addition, the coexistence of MTHFR C677T with FV-Leiden was seen in 10.4% of CAD patients compared 6.9% of controls (p = 0.001). CONCLUSION: While results from this study clearly demonstrate a strong association of hyperhomocysteinemia and homozygosity of the MTHFR C677T, but not FV-Leiden or PRT G20210A, mutations with confirmed CAD, they also suggest a potential role for factor V-Leiden in MTHFR C677T carriers.     

The frequency of factor V Leiden and concomitance of factor V Leiden with prothrombin G20210A mutation and methylene tetrahydrofolate reductase C677T gene mutation in healthy population of Denizli, Aegean region of Turkey.

Factor V Leiden causing activated protein C resistance is the most common inherited form of thrombophilia leading to thrombosis. Its frequency shows great ethnic and geographic variations. The aim of this study was to determine the frequency of FV Leiden and coinheritance of FV Leiden with two other frequent hereditary thrombophilia causes, namely, prothrombin G20210A and methylene-tetrahydrofolate reductase (MTHFR) C677T mutation in the Aegean region of Turkey. The study population consisted of 1030 (500 men and 530 women) apparently healthy subjects. Functional resistance to activated protein C (APC) was measured by using the test kit STA staclot APC-R ((Diagnostica Stago, Asnieres, France, Cat. No. 00721). In subjects with APC resistance, molecular analyses of FV Leiden and of prothrombin G20210A and MTHFR C677T mutation were performed by using FV-PTH-MTHFR StripA (Vienna Lab, Labordiagnostika GmbH, Austria) kit, which was based on hybridization of polymerase chain reaction (PCR) amplified DNA products with mutation-specific oligonucleotide probes. Functional APC resistance was present in 93 subjects (9%). FV Leiden mutation was found in 87 of 93 subjects with APC resistance by PCR method. The FV Leiden carrier frequency was found to be 8.4% (87/1030). Seventy-six individuals were heterozygous (7.3%), and 11 were homozygous (1.06%). Among the 87 subjects with FV Leiden mutation, 45 subjects had MTHFR C677T gene mutation (7 homozygous, 38 heterozygous) and 4 subjects had heterozygote prothrombin G20210A gene mutation. A combination of FV Leiden and prothrombin G20210A and MTHFR C677T gene mutation was detected in 3 subjects. The results indicate that FV Leiden prevalence is quite high and coexistence of FV Leiden with other hereditary causes of thrombosis such as prothrombin G20210A mutation and MTHFR enzyme defect is not rare in healthy population of Aegean region of Turkey.     

A Case Control Study on the Contribution of Factor V-Leiden,Prothrombin G20210A,and MTHFR C677T Mutations to the Genetic Susceptibility of Deep Venous Thrombosis

Background: Insofar as the inherited prothrombotic single nucleotide polymorphisms (SNPs) factor V G1691A (FV-Leiden), prothrombin (PRT) G20210A, and methylenetetrahydrofolate reductase (MTHFR), C677T are inherited risk factors of venous thromboembolism (VTE), the aim of this study was to determine the prevalence of single and combined SNPs in 198 patients with documented deep venous thrombosis (DVT), and 697 control subjects, and to estimate the associated risks.Methods: Factor V-Leiden, PRT G20210A, and MTHFR C677T were analyzed by PCR and restriction fragment length polymorphism (RFLP).Results: The prevalence of the heterozygote and homozygous variants for FV-Leiden (52.02 vs. 14.78%, RR 6.28), PRT G20210A (19.2 vs. 3.6%; RR 6.38), and to a lesser extent the T/T genotype of MTHFR C677T (20.71 vs. 11.0%; RR 1.49) were higher among DVT patients vs. controls, respectively. Two or more SNPs were detected in 90 of 198 patients (45.5%) and in 60 of 697 controls (8.6%), with odds ratios of 16.754 for joint occurrence of FV-Leiden and PRT G20210A, 10.471 for FV-Leiden and MTHFR C677T, and 6.283 for PRT G20210A SNPs and MTHFR 677T/T. Logistic regression analysis showed a further increased odds for FV-Leiden in combination with PRT G20210A (85.198) or homozygous MTHFR C677T (81.133), and to a lesser extent for PRT G20210A in combination with homozygous MTHFR C677T (20.812).Conclusions: This indicates that FV-Leiden and PRT G20210A, more than MTHFR C677T, are important risk factors for DVT, and that the presence of more than one prothrombotic SNPs was associated with a significant risk of DVT.     

Varied Prevalence of Factor V G1691A (Leiden) and Prothrombin G20210A Single Nucleotide Polymorphisms Among Arabs

Background: Factor V G1691A (FV-Leiden) and prothrombin (PRT) G20210A single nucleotide polymorphisms (SNPs) are major inherited risk factors of venous thromboembolism. In view of the heterogeneity in their world distribution and lack of sufficient information about their distribution among Arabs, we addressed the prevalence of both SNPs in 4 distinct Arab populations (Lebanon, Tunisia, Bahrain, and Saudi Arabia). Methods: Study subjects comprised 698 Lebanese, 313 Tunisian, 194 Bahraini, and 149 Saudi Arabian healthy subjects; genotyping was done by PCR-RFLP using Mnl I and Hind III for FV-Leiden and PRT G20210A, respectively. Results: The prevalence of the mutant A alleles of FV-Leiden and PRT G20210A were significantly higher among Lebanese (0.0788 and 0.0136) and Tunisians (0.0351 and 0.0128), as compared to Bahraini (0.0155 and 0.0052) and Saudi (0.0101 and 0.000) subjects. Higher frequency of the FV-Leiden G/A and A/A genotypes were seen in Lebanon (13.8 and 1.0%), followed by Tunisia (5.8 and 0.6%), Bahrain (3.1 and 0.0%) and Saudi Arabia ((2.0 and 0.0%). All PRT G20210A positive cases were in the heterozygote (G/A) state, and these comprised 3.6% for Lebanon, 2.6% for Tunisia, 1.0% for Bahrain. The carrier rate of FV-Leiden was significantly higher among Lebanese compared to the other populations (p < 0.001), while the difference in the prevalence of FV-Leiden between the other populations was not statistically different. With the exception of Lebanese-Saudi (p = 0.038), the prevalence of PRT G20210A was similar among the study communities. Furthermore, the overall average genetic differentiation between populations (estimated with the F_ST) was 0.0022 for FV-Leiden and 0.005 for PRT G20210A. Conclusions: These results further confirm the heterogeneity in FV-Leiden and PRT G20210A distribution among Arabs, and recommend potential institution of prophylactic measures for carriers of either or both SNPs.     

Factor V Leiden and G20210A prothrombin mutations in patients with recurrent pregnancy loss: data from the southeast of Turkey

Factor V Leiden (FV-Leiden) and prothrombin gene mutations (FII G20210A) are well-established independent risk factors for thrombosis. In the recent years, many studies have suggested that these mutations are associated with an increased risk of recurrent pregnancy loss (RPL). We aimed to investigate the prevalence of these molecular defects in subjects with a history of early RPL. One hundred and fourteen women with three or more consecutive unexplained first-trimester miscarriages were compared to 185 parous women with uncomplicated pregnancies from the same ethnic origin. The presence of FV-Leiden and FII G20210A mutations was assessed by polymerase chain reaction analysis. Overall, 11 out of the 114 women with early RPL (9.6%) had either FV-Leiden or FII G20210A mutation, as compared with 16 out of the 185 women with normal pregnancies (8.6%; p = 0.756). The prevalence of FV-Leiden mutation was 7.9% (9/114) in patient group, compared with 7% (13/185) in control group (p = 0.780). One hundred and two patients were primary and 12 were secondary aborters. All FV-Leiden positive cases were primary aborters (8.8%; 9/102, p = 0.584). Concerning the FII G20210A, two out of 114 (1.7%) were first-trimester RPL (primary aborters) and three out of 185 (1.6%) controls were carriers of the FII G20210A mutation (1.7 vs 1.6%, p = 0.931). The results obtained from patients with first-trimester RPL and the control group have no statistical significant differences in the prevalence of FV-Leiden and FII G20210A mutations. These results suggest that mutations have no role in etiology of first-trimester recurrent abortions.     

Factor V-Leiden, prothrombin G20210A, and MTHFR C677T mutations among patients with sickle cell disease in Eastern Saudi Arabia

The prevalence of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations were investigated among 87 Saudi sickle cell disease (SCD) patients (38 males and 49 females) and 105 healthy controls (65 males and 40 females). The prevalences of factor V Leiden (P = 0.174) and PRT G20210A (P = 0.397) were not different between patients and controls, thereby giving no support to an association of either single-point mutation with SCD. However, an increased prevalence of the MTHFR 677 T/T genotype was seen among patients (8/87) compared to controls (4/105), but this was not statistically significant (P = 0.217; OR = 2.56). This suggested a low impact of inherited hypercoagulability risk factors in the pathogenesis of SCD and/or its complications.     

Risk of venous thrombosis in carriers of the prothrombin G20210A variant and factor V Leiden and their interaction with oral contraceptives

BACKGROUND AND OBJECTIVES: The prothrombin G20210A mutation and factor V Leiden have been found to be associated with an increased risk of venous thrombosis, but the reported prevalences of the prothrombin gene variant both in the normal population and in patients with deep venous thrombosis (DVT) vary greatly in the literature. Moreover, the influence of oral contraceptives (OC) on thrombotic events in patients with the prothrombin G20210A variant has not been well established. In this study we evaluate both circumstances. DESIGN AND METHODS: A case-control study was run on 229 patients with DVT and 246 healthy controls. The patients' history of thrombosis and acquired thrombotic risk factors, especially OC, were recorded. Prothrombin G20210A mutation, factor V Leiden, antithrombin, heparin II cofactor, plasminogen and proteins C and S were evaluated. RESULTS: Seven and a half percent of the patients and 2.9% of the controls were carriers of the prothrombin mutation, while 12.2% of the patients and 1.6% of the controls had factor V Leiden. Among the 229 DVT patients there were 130 patients with clinically suspected thrombophilia (first thrombotic event occurring before the age of 45 years or positive family history of thrombosis or recurrent venous thrombosis). Ten percent of these 130 patients were carriers of the prothrombin G20210A mutation and 18.5% had the factor V Leiden mutation. The odds ratios (OR) for DVT risk were: 2.4 (95% CI, 1.0-6.3) for the total DVT patients and 5.2 (95% CI, 1.4-19.5) for the patients with clinically suspected thrombophilia with the prothrombin mutation. The risk of thrombosis was 6.9 (95% CI, 2.3-20.6) for the DVT patients and 14.3 (95% CI, 3.3-64.6) for the patients with clinically suspected thrombophilia with factor V Leiden. Fifty-five percent of the patients with combined congenital defects (prothrombin mutation G20210A plus another congenital defect) had recurrent thrombosis. In women receiving OC the risk of DVT was 3.5 (95% CI, 1.5-8.2) that of the patients not receiving OC. When women with combined defects were also taking OC, the risk of thrombosis increased significantly. INTERPRETATION AND CONCLUSIONS: The prevalence of the prothrombin G20210A mutation in the healthy population in our study is similar to that observed in other southern European countries. The prothrombin G20210A mutation does not by itself seem to be a high thrombotic risk factor. However, when it is present together with other thrombotic risk factors, the predicted risk of thrombotic events increases. The use of OC by women with the prothrombin G20210A variant or FV Leiden, either alone or combined with other thrombotic risk factors, was associated with a significant increase in the risk of venous thrombosis.     

Combined genetic defect (homogeneity for factor V Leiden and heterogeneity for prothrombin G20210A allele), in a young patient, with recurrent deep vein thrombosis and serious postphlebitic syndrome--a case report

Just a few years ago, resistance to activated protein C (APCR) was reported to be of high significance representing a strong predisposing factor in the development of venous thrombosis (VT). A little while later, APCR was established to be the result of a point mutation of the factor V gene (factor V Leiden: a G-to-A transition at position 1691). Up to today, it is not certain whether factor V Leiden is in itself able to lead to VT, or whether it acts in synergy with other factors. Nevertheless, heterozygous subjects have a tenfold increase in the risk of VT when compared to general population, whereas the risk is 80 times greater in homozygous individuals. In 1996, a prothrombin gene mutation (prothrombin G20210A allele), which is a single-nucleotide G-to-A transition at position 20210 in the sequence of the 3'-untranslated region (3'UTR) on chromosome 11, was discovered. The presence of this mutant gene results in elevated plasma prothrombin concentrations, increasing the possibility for the development of VT. However, the coexistence of these two abnormalities, as well as the clinical consequence, have not yet been studied. So far, only a few reports are found in the literature describing the coexistence of both mutations. The authors present a 25-year-old patient with a simultaneous double mutation of the FV and F II gene. The patient was homozygous for the factor V Leiden and heterozygous for the prothrombin G20210A allele. It is unclear whether the coexistence of the two predisposes more to the development of VT than the summation of the two as independent factors.     

Intraindividual consistency of the activated protein C resistance phenotype

Resistance to activated protein C (APC) has been demonstrated to be a risk factor for venous thromboembolism, but it is not known whether this phenotype is consistent over time. We reinvestigated 2580 subjects from the Vicenza Thrombophilia and Atherosclerosis (VITA) Project to evaluate the prevalence of a consistent APC resistance phenotype in the population. Among the 433 subjects with an APC resistance at first visit, the phenotype was confirmed in all the 74 factor V (FV) Leiden carriers and in 124 of 359 FV Leiden negative subjects (34%). The prevalence of a confirmed phenotype, not associated with FV Leiden, was 4.8% in our population. In a subgroup of subjects previously investigated for heritability of the APC resistance, we confirmed the APC resistance phenotype in seven of 39 (17.9%) subjects with an APC resistant sibling but only in 20 of 408 (4.9%) subjects without a sibling with the same phenotype (P = 0.005). Among the 124 FV Leiden negative subjects with a persistent APC resistance phenotype, 40 (32%) had a plasma factor VIII coagulant activity level above 150 IU/dl and eight (6.4%) were carriers of the G20210A prothrombin allele. APC resistance not due to FV Leiden is a frequent and consistent phenotype in the general population, with a possibly strong genetic influence.     

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.     

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.     

Inherited thrombophilia is associated with deep vein thrombosis in a Colombian population

The development of venous thromboembolism is influenced by a variety of genetic and environmental risk factors. A few studies have ascertained whether thrombophilic defects are risk factors for venous thromboembolism in Latin American populations with a variable degree of admixture, such as the Colombian population. To address this issue, we conducted a case-control study involving 100 consecutive patients with deep vein thrombosis and 114 healthy controls from the Hospital Universitario San Vicente de Paúl, Medellín, Colombia. Activated protein C resistance (APC resistance) was detected in 25/99 patients vs. 6/114 controls (OR = 6.08, 95% CI = 2.23-17.47). Ten of 100 patients carried the factor V Leiden mutation vs. 1/114 controls (OR = 12.56, 95% CI = 1.61-267). APC resistance was associated with the factor V Leiden mutation in only 10/25 patients. The prothrombin G20210A mutation was found in 4/100 patients, but none of the controls (P < 0.05). There was no significant difference in the proportion of homozygous carriers of methylenetetrahydrofolate reductase C677T variant among patients and controls. In conclusion, in our studied population, factor V Leiden, APC resistance, and prothrombin G20210A were associated with an increased risk of deep vein thrombosis. However, the frequencies of these thrombophilic defects and of APC resistance associated with factor V Leiden was lower than the corresponding frequencies previously reported for Caucasian populations. Further study is required to assess the influence of ethnicity on thrombophilia.     

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.     

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.     

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.     

Factor V Leiden G1691A, prothrombin G20210A, and MTHFR C677T mutations in Turkish inflammatory bowel disease patients

BACKGROUND/AIMS: Patients with inflammatory bowel disease (IBD) have an increased risk for thromboembolic complications. We investigated the incidence of factor V Leiden G1691A, methylene tetrahydrofolate reductase (MTHFR) C677T, and prothrombin G20210A mutation in 27 Turkish IBD patients with no history of thromboembolic disease. METHODOLOGY: Twenty-seven patients, 22 with ulcerative colitis (UC) and 5 with Crohn's disease (CD), and 47 healthy were included to the study. The DNAs were obtained from peripheral blood by using pure polymerase chain kit. Then, factor V Leiden G1691A, which active protein C resistance positive, prothrombin G20210A and MTHFR C677T mutations were investigated in DNA by using LightCycler-Factor V Leiden G1691A mutation, Prothrombin G20210A and MTHFR C677T estimate kits. RESULTS: The heterozygote factor V Leiden G1691A mutation was detected in 3 (11.1%) patients with IBD and 2 (4.3%) controls (p > 0.05). The homozygote factor V Leiden G1691A mutation was not estimated among patients and controls. Heterozygote prothrombin G20210A mutation was detected in 2 (7.4%) patients with IBD and in 0 (0%) controls (p > 0.05). There was no homozygote prothrombin G20210A mutation in IBD and controls. Heterozygote MTHFR C677T mutation was 10 of 27 (37%) patients with IBD while 15 of 47 (32%) controls (p > 0.05). Homozygote MTHFR C677T mutation was detected in 4 patients (14.9%) with IBD and 3 (6.3%) controls (p > 0.05). CONCLUSIONS: Our study did not reveal any association between IBD and the most common hereditary thrombophilic factors and these mutations interfere with neither disease manifestations nor the thrombotic complications.     

Primary thrombophilia in Mexico. II. Factor V G1691A (Leiden), prothrombin G20210A, and methylenetetrahydrofolate reductase C677T polymorphism in thrombophilic Mexican mestizos.

We have shown that in Mexican mestizo patients with clinical features of primary thrombophilia, 39% have activated protein C resistance phenotype, 5% protein C deficiency, and 2% protein S deficiency. In the present study, in a group of 37 thrombophilic Mexicans and 50 normal controls, we assessed the factor V G1691A (Leiden), the prothrombin G20210A, and the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms. Four patients were found to be heterozygous for factor V Leiden, 5 heterozygous for the prothrombin 20210, 16 heterozygous, and 6 homozygous for the MTHFR 677. There were four individuals with co-segregation of alleles: two heterozygotes for the factor V Leiden/prothrombin 20210, one heterozygote for prothrombin 20210/MTHFR 677, and one heterozygote for prothrombin 20210/homozygote for MTHFR 677. For factor V Leiden, prothrombin 20210, and MTHFR 677 mutations, the allele frequencies were respectively 1% (+/-0.2%, alpha = 0.05), <1% and 51% (+/-5%, alpha = 0.05), with calculated relative risks for thrombosis of 5.94 (P = 0.08), >7.66 (P < 0.05), and 0.44 (P NS), respectively. In Mexican mestizo thrombophilic patients, the low prevalence of the factor V Leiden mutation (10.8%) and the high prevalence of the prothrombin 20210 mutation (13.5%) contrast with those identified in Caucasian thrombophilic patients (21% and 6%, respectively; P < 0.01). On the other hand, the high prevalence of the MTHFR 677 mutation gene both in normal controls (78%) and thrombophilic patients (61%) does not support a role of this mutation in the thrombogenesis of Mexican mestizo patients.