Factor V Leiden, MTHFR, and FXIIIVal34Leu gene polymorphisms and their association with clinical features and risk of diabetic retinopathy in patients with type 2 diabetes

Background

Diabetic retinopathy (DR) is expanding to epidemic levels globally due to the progressing prevalence of diabetes mellitus (DM). In this study, the association between factor V Leiden (FVL), MTHFRC677T, and FXIIIVal34Leu polymorphisms and diabetic retinopathy was investigated in Eastern Iran.

Methods

This case-control study enlisted the participation of 300 people (diabetic patients=100, diabetic retinopathy patients=100, healthy controls=100), and polymorphisms were examined by Tetra primer ARMS-PCR.

Results

The frequency of FVL (p=0.294) and FXIIIVal34Leu (P=0.349) polymorphism showed no significant results between the genotype frequency in the mentioned groups. In contrast, MTHFRC677T SNP was significantly different in diabetic patients and controls (P=0.008). The MTHFRC677T polymorphism was found to be connected with increased systolic blood pressure in patients who had the TT genotype (130.96±11.92mm/Hg; P=0.011).

Conclusion

Our study recommended that the MTHFRC677T polymorphism may offer to DR development. Studies with larger sample sizes and a wider spectrum of populations are authorized to verify this finding.

Association between Factor-V Leiden and occurrence of acute myocardial infarction using a large NIS database

Factor V Leiden is an inheritable pro-thrombotic genetic condition caused by a point mutation at the 506th codon, resulting in activated protein C resistance. APC resistance has been shown to contribute to the development of venous thrombosis. However, the role of FVL in AMI has yet to be well defined in the current literature. To assess whether a mutation carrier is more apt to develop an AMI, we conducted a retrospective observational analysis of two populations aged 18-40 and 18 through end of life. We used ICD-10 codes to search the NIS, an electronic nationwide patient database, to establish our populations and obtain our data. The ICD-10 codes were specific for activated protein C resistance and acute myocardial infarction. Preliminary data indicated that FVL was related to AMI; however, this finding became insignificant in both populations when stratified for age. We concluded there was no association between Factor V Leiden and acute myocardial infarction across both examined populations. Future investigations into this field of research are warranted as there remains a need for more consensus among the scientific community.

BACKGROUND

Medical literature regarding the correlation between Factor V Leiden (FVL) and acute myocardial infarctions (AMI) is controversial. We aim to investigate the association between FVL and AMI.

MATERIALS AND METHODS

Using the Nationwide Inpatient Sample database, we evaluated any association between Factor V Leiden and acute myocardial infarction in 2016 using ICD-10 codes.

RESULTS

Univariate analysis (18-40) showed an increase of AMI in patients with FVL 0.6% vs. 0.4%. However, after adjustment for age and comorbid conditions in multivariate analysis, FVL was not significantly associated with acute myocardial infarction (OR 1.44 (95% CI 0.913-2.273, p-value 0.117)). Univariate analysis (all patients over 18 years old) found that 2.9% of patients with FVL experienced AMI vs. 4.4% without the mutation. Multivariate analysis of the entire population ultimately showed no correlation between FVL and AMI.

CONCLUSION

In a population over 18, Factor V Leiden did not correlate with an increased risk of acute myocardial infarction in our studied population.

Combined Parental Thrombophilia Gene Mutation Defects in Couples with Repeated Pregnancy Loss

Background

Several genetic mutations in female thrombotic defects have recently been shown to affect recurrent pregnancy loss (RPL); however, it is unclear which common parental mutations are involved in thrombosis-associated repeated pregnancy loss RPL.

Aims

In this study, the prevalence of some combined parental thrombophilia gene mutation defects was studied in couples with RPL.

Settings and Design

The observational study was done in babol infertility research center (Iran) in 2022.

Materials and Methods

Sixty-two infertile women with a history of RPL and their male partners (124 individuals) participated in this study. The frequencies of common defects associated with methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, factor V Leiden, protein C, protein S and homocysteine were analysed in these couples.

Statistical analysis used

The data were statistically analysed using the Mann-Whitney test.

Results

Sixty-two couples (124 individuals) were analysed. 56.2% of couples with a history of RPL had MTHFR C677T and 23.1% had MTHFR A1298C. Forty percent of couples showed homocysteine deficiency and 12.5% protein C deficiency. Other genes tested were only observed in the mother or father but not both.

Conclusions

Results obtained with RPL couples demonstrate the importance of further investigating combined parental thrombophilia gene mutation defects (not only maternal).

Cancer-associated thrombosis by cancer sites and inherited factors in a prospective population-based cohort

Cancer-associated thrombosis (CAT) is common and associated with mortality. We estimated CAT rate by cancer sites and inherited factors among cancer patients from the UK Biobank (N =70,406). The 12-month CAT rate after cancer diagnosis was 2.37% overall but varied considerably among cancer sites. Among the 10 cancer sites classified as 'high-risk' of CAT by the National Comprehensive Cancer Network guidelines, 6 had CAT rate <5%. In contrast, 5 cancer sites classified as 'average-risk' by the guidelines had CAT rate >5%. For inherited risk factors, both known mutation carriers in two genes (F5/F2) and polygenic score for venous thromboembolism (VTE) (PGSVTE) were independently associated with increased CAT risk. While F5/F2 identified 6% patients with high genetic-risk for CAT, adding PGSVTE identified 13 % patients at equivalent/higher genetic-risk to CAT than that of F5/F2 mutations. Findings from this large prospective study, if confirmed, provide critical data to update guidelines for CAT risk assessment.

Ghost Cell Odontogenic Carcinoma: A Case Report and Literature Review

Ghost cell odontogenic carcinoma (GCOC) is an exceptionally rare malignant odontogenic neoplasm with a significant potential for aggressive growth. Although the literature on this tumor is limited, its high recurrence rates suggest that early and multimodal intervention may be beneficial. This study reports a case of GCOC of the mandible that was successfully treated with surgical resection, reconstruction, and radiation. A comprehensive literature review was performed, and the relevant genomic and histopathological characteristics of this malignancy were determined. Laryngoscope, 133:830-833, 2023.

Massive Left Ventricular Thrombus After ST-Segment Elevation Myocardial Infarction in a Young Man With Factor V Leiden

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STEMI caused by obstructive CAD is uncommon in young adults.

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Factor V Leiden and antipsychotic medication use may increase the risk for ACS.

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LV thrombus is a common complication of acute anterior STEMI.

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TTE is the most common imaging modality used in diagnosing LV thrombus.

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Anticoagulation therapy for LV thrombus should be individually tailored.

Contribution of genotypes in Prothrombin and Factor V Leiden to COVID-19 and disease severity in patients at high risk for hereditary thrombophilia

Thrombotic and microangiopathic effects have been reported in COVID-19 patients. This study examined the contribution of the hereditary thrombophilia factors Prothrombin (FII) and Factor V Leiden (FVL) genotypes to the severity of COVID-19 disease and the development of thrombosis. This study investigated FII and FVL alleles in a cohort of 9508 patients (2606 male and 6902 female) with thrombophilia. It was observed that 930 of these patients had been infected by SARS-CoV-2 causing COVID-19. The demographic characteristics of the patients and their COVID-19 medical history were recorded. Detailed clinical manifestations were analyzed in a group of cases (n = 4092). This subgroup was age and gender-matched. FII and FVL frequency data of healthy populations without thrombophilia risk were obtained from Bursa Uludag University Medical Genetic Department's Exome Databank. The ratio of males (31.08%; 27.01%) and the mean age (36.85 ± 15.20; 33.89 ± 14.14) were higher among COVID-19 patients compared to non-COVID-19 patients. The prevalence of FVL and computerized tomography (CT) positivity in COVID-19 patients was statistically significant in the thrombotic subgroup (p < 0.05). FVL prevalence, CT positivity rate, history of thrombosis, and pulmonary thromboembolism complication were found to be higher in deceased COVID-19 patients (p < 0.05). Disease severity was mainly affected by FVL and not related to genotypes at the Prothrombin mutations. Overall, disease severity and development of thrombosis in COVID-19 are mainly affected by the variation within the FVL gene. Possible FVL mutation should be investigated in COVID-19 patients and appropriate treatment should be started earlier in FVL-positive patients.

Evaluation of Activated Protein C Resistance Using Thrombin Generation Test

Activated protein C (APC) resistance (APCR) has been identified as a risk factor of venous thromboembolism (VTE). A mutation at the level of factor (F) V has at first permitted the description of this phenotypic pattern and corresponded to a transition (guanine to adenine) at nucleotide 1691 in the gene coding for factor V, resulting in the replacement of arginine at position 506 by a glutamine. This confers to this mutated FV a resistance toward the proteolytic action of the complex formed by activated protein C with protein S. However, many other factors also lead to APCR, such as other F5 mutations (e.g., FV Hong Kong and FV Cambridge), protein S deficiency, elevated factor VIII, exogenous hormone use, pregnancy, and postpartum. All these conditions lead to the phenotypic expression of APCR and are associated with an increased risk of VTE. Considering the large population affected, the proper detection of this phenotype is a public health challenge. Currently, two types of tests are available: clotting time-based assays and their multiple variants and a thrombin generation-based assays and the endogenous thrombin potential (ETP)-based APCR assay. As APCR was thought to be uniquely related to the FV Leiden mutation, clotting time-based assays were specifically designed to detect this inherited condition. Nevertheless, other APCR conditions have been reported but were not captured by these clotting methods. Thus, the ETP-based APCR assay has been proposed as a global coagulation test able to these multiple APCR conditions, as it provides much more information, which makes it a potential candidate for screening coagulopathic conditions before therapeutic interventions. This chapter will describe the current method used for the realization of the ETP-based APC resistance assay.

Testing for Factor V Leiden (FVL) and Prothrombin G20210A Genetic Variants

Laboratory testing for Factor V Leiden and Prothrombin G20210A genetic variants permits defining the increased relative risk for venous thromboembolism in selected patients. Laboratory DNA testing for these variants may be undertaken by a variety of methods, including fluorescence-based quantitative real-time PCR (qPCR). This is a rapid, simple, robust, and reliable method to identify genotypes of interest. This chapter describes the method that employs PCR amplification of the patient DNA region of interest and genotyping by allele-specific discrimination technology on a quantitative real-time PCR (qPCR) instrument.

The prognostic role of extended preoperative hypercoagulability work-up in high-risk microsurgical free flaps: a single-center retrospective case series of patients with heterozygotic factor V Leiden thrombophilia

INTRODUCTION

Hypercoagulability is associated with an increased risk of microvascular complications and free flap failures. The authors present their experience and approach to diagnosing and treating patients with heterozygotic factor V Leiden (hFVL) thrombophilia undergoing free flap reconstruction.

METHODS

Between November 2009 and June 2018, 23 free flap surgeries were performed in 15 hypercoagulable patients with hFVL. According to the timing of perioperative hypercoagulability work-up, they were grouped into flaps with established diagnoses prior to surgery (Group A) versus flaps with unknown diagnoses prior to surgery (Group B). Baseline characteristics and perioperative complications were compared between both groups, including revision surgeries due to microvascular thromboses, acute bleedings, hematomas, flap necroses, and reconstructive failures.

RESULTS

HFVL mutations had been confirmed preoperatively in 14 free flap surgeries (61%, Group A), whereas in 9 free flap surgeries (39%, Group B), mutations were only diagnosed postoperatively after the occurrence of microvascular thromboses had warranted extended hypercoagulability work-up. The overall rate of intraoperative flap thromboses was 9% (n = 2), whereas the overall rate of postoperative flap thromboses was 43% (n = 10). The corresponding salvage rates were 100% (n = 2/2) for intraoperative and 40% (n = 4/10) for postoperative pedicle thromboses. A total of five free flaps were lost (22%). Upon comparison, flaps with an unconfirmed diagnosis prior to surgery were at ten times higher risk for developing total necroses (flaps lost in Group B = 4/9 versus Group A = 1/14; OR: 10.4; 95% CI 1.0, 134.7; p = 0.03).

CONCLUSION

Meticulous preoperative work-up of patients with any history of hypercoagulability can help reduce free flap loss rates, thus improving surgical outcomes and increasing patient safety.

Factor V Leiden and the 10-year incidence of depression: A retrospective cohort study conducted in Germany

There is limited literature on the long-term relationship between the diagnosis of factor V Leiden (FVL) and depression. Therefore, the aim of this retrospective cohort study was to investigate the association between FVL and the 10-year incidence of depression in Germany. Patients diagnosed with FVL for the first time in one of 1,274 general practices in Germany between 2000 and 2019 were included in this study (index date). Patients without FVL were matched (1:5) to those with FVL by sex, age, index year, and the average number of consultations per year. In individuals without FVL, index date corresponded to a randomly selected visit date between 2000 and 2019. The association between the diagnosis of FVL and the 10-year incidence of depression was analyzed using Kaplan-Meier curves and Cox regression models. This study included 1,070 patients with and 5,350 patients without FVL (64.9% women; 46.0 [16.5] years). Ten years after the index date, 21.4% and 14.1% of individuals with and without FVL were diagnosed with depression, respectively (log-rank p-value<0.001). After adjusting for thromboembolic events, the Cox regression analysis further showed that FVL was associated with a significant increase in the incidence of depression (HR = 1.61, 95% CI = 1.33-1.95). In this study conducted in Germany, FVL was identified as a long-term risk factor for depression. More research is needed to confirm or refute the present findings in other settings.

A case-control study on factor V Leiden: an independent, gender-dependent risk factor for venous thromboembolism

BACKGROUND

Activated protein C resistance (APCR) due to factor V Leiden (FVL) mutation (R506Q) is a major risk factor in patients with venous thromboembolism (VTE). The present study investigated the clinical manifestations and the risk of venous thromboembolism regarding multiple clinical, laboratory, and demographic properties in FVL patients.

MATERIAL AND METHODS

A retrospective cross-sectional analysis was conducted on a total of 288 FVL patients with VTE according to APCR. In addition, 288 VET control samples, without FVL mutation, were also randomly selected. Demographic information, clinical manifestations, family and treatment history were recorded, and specific tests including t-test, chi-square and uni- and multi-variable regression tests applied.

RESULTS

APCR was found to be 2.3 times significantly more likely in men (OR: 2.1, p < 0.05) than women. The risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) in APCR patients was 4.5 and 3.2 times more than the control group, respectively (p < 0.05). However, APCR could not be an independent risk factor for arterial thrombosis (AT) and pregnancy complications. Moreover, patients were evaluated for thrombophilia panel tests and showed significantly lower protein C and S than the control group and patients without DVT (p < 0.0001).

CONCLUSION

FVL mutation and APCR abnormality are noticeable risk factors for VTE. Screening strategies for FVL mutation in patients undergoing surgery, oral contraceptive medication, and pregnancy cannot be recommended, but a phenotypic test for activated protein C resistance should be endorsed in patients with VTE.

Prevalence of rare F5 variants in general population from Bosnia and Herzegovina

Human gene F5, encoding coagulation factor V, was previously reported to be highly polymorphic. Apart from FV Leiden, several other rare variants have been detected in clinical practice and associated with thrombotic events, especially in cases when patient's phenotype and FV Leiden genotype were not in agreement. In this study, the prevalence of 17 rare F5 variants has been studied on a sample of 130 healthy adult individuals from the general Bosnian-Herzegovinian population. DNA was isolated from buccal swab samples, while genotyping was performed using MALDI-TOF MS method. The results have shown that Asp2194Gly and Met2120Thr are polymorphic in the study population with minor allele frequencies of 0.077 and 0.073, respectively. Additionally, these two variants were mutually exclusive with FV Leiden and none of them was positively associated with participants' family history of cardiovascular or cerebrovascular diseases. While the obtained results are in agreement with previously reported data for the general Caucasian populations, it is worth noting that only two rare F5 variants were detected in the study population, albeit at considerable frequencies. Still, scientific information on rare F5 variants is rather scarce and further studies aiming to assess functional importance of these variants, as well as their role as prothrombotic factors are necessary.

Homozygous Factor V Leiden presenting as irreversible chronic colon ischemia resulting from inferior mesenteric vein thrombosis

A 42-year-old man presented with 6 months of unexplained left lower quadrant abdominal pain and hematochezia accompanied by weight loss despite extensive evaluations. Stool studies for pathogens were unrevealing, but an abdominal contrast-enhanced computed tomography revealed findings of chronic inferior mesenteric vein thrombosis. Colonoscopy demonstrated ulcerated strictures and gangrene confined to the sigmoid and descending colons, and biopsies confirmed changes of chronic irreversible colon ischemia. A homozygous Factor V Leiden mutation was diagnosed. The patient underwent colectomy and was treated with lifelong anticoagulation. While mesenteric venous thrombosis is a well-recognized cause of colon ischemia in hypercoagulable states, thrombosis of the inferior mesenteric vein is uncommon; when chronic it is rarely clinically apparent. Similarly, while Factor V Leiden mutation is a common hereditary thrombophilia, it uncommonly causes mesenteric venous thrombosis, and homozygotes of the mutation typically present earlier in the fourth decade and with non-mesenteric venous thromboembolism. This case is valuable and adds to the existing literature in describing a rare, clinically atypical, and late index presentation of homozygous Factor V Leiden mutation as chronic inferior mesenteric vein thrombosis yielding irreversible colon ischemia.

Targeted next-generation sequencing reveals novel and known variants of thrombophilia associated genes in Saudi patients with venous thromboembolism

BACKGROUND

Thrombophilia is a substantial source of indisposition and mortality in several countries, including Arab populations. Deep venous thrombosis (DVT) with or without pulmonary embolism (PE) is the prevalent clinical manifestation of thrombophilia. While many genetic risk factors for DVT are known, almost all associated with hemostasis, many genetic factors remain unexplained. Nowadays, Next Generation Sequencing (NGS) offers a potential solution that allows several candidate genes to be analyzed simultaneously at a reasonable expense.

METHODS

We performed variant screening in the thrombophilia associated genes in Factor V Leiden (FVL) mutation-negative patients using Ion Torrent Next-generation sequencing (NGS). Ion AmpliSeq panel for 18 genes was designed. Twenty-nine unrelated patients with idiopathic VTE were recruited for NGS.

RESULTS

We were able to identify 19 variants (1 novel and 18 previously reported) in 10 out of 18 targeted genes. Pathogenic variants were identified in 22 patients demonstrating mutation detection rates of 76%. Previously reported variants in the F5, MTHFR, PROS1, PROC, F8, F9, SERPINA10, SERPIND1, and HRG genes were recognized in 21 patients. More than one variant in the targeted genes was detected in some of the patients with VTE. We identified SERPINA10 recurrent variant p.(R88*) in seven patients representing 32% of VTE cases. Additionally, we report one novel variant c.356G > T, p.(G119V) in the F7 gene, considered to be pathogenic in this study.

CONCLUSIONS

Our studies finding illustrates the ability of targeted next-generation sequencing to uncover uncommon/unknown genetic variants that may predispose to thrombophilia. The finding of the novel variant in the F7 gene extends the spectrum of variants affecting thrombosis. While a comparatively small number of subjects have been included in our cohort, the findings summarize the possible genetic features of thrombophilia.

Ruptured idiopathic hepatic artery pseudoaneurysm causing portal vein thrombosis with portal hypertension and variceal bleeding

Portal vein thrombosis (PVT) is an important cause of noncirrhotic portal hypertension. Noncancerous extrinsic compression of portal vein to drive PVT formation is rare, but important to identify. A 64-year-old female with idiopathic hepatic artery pseudoaneurysm (HAPA) rupture 7 months prior presented with acute-onset hematemesis and melena and was found to have prehepatic portal hypertensive variceal bleeding. Her HAPA-related retroperitoneal hematoma had resulted in portal vein compression, thrombosis, and cavernous transformation despite prompt stent graft placement across the ruptured HAPA, and required definitive treatment by transjugular intrahepatic portosystemic shunt creation with portal vein reconstruction utilizing a trans-splenic access. This case highlights the importance of interval abdominal imaging and hypercoagulability screening for noncirrhotic patients at-risk for PVT, which identified the patient as a heterozygous carrier of Factor V Leiden.

Education Case: Hereditary Thrombophilia With Double Heterozygous Factor V Leiden and Factor II c.*97G>A Mutations

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.¹.

Impact of double heterozygosity for Factor V Leiden and Prothrombin G20210A on the thrombotic phenotype

INTRODUCTION

Because of the rarity of double heterozygosity for Factor V Leiden (FVL) and Prothrombin (FII) G20210A, little is known about the thrombotic phenotype in double heterozygotes.

MATERIAL AND METHODS

In a retrospective cohort study of patients referred for a thrombophilia work-up, we investigated whether double heterozygotes (n = 138) exhibit a more severe thrombotic phenotype compared with single FVL or FIIG20210A heterozygotes, single FVL homozygotes, or wildtype carriers.

RESULTS

The risk of venous thromboembolism (VTE) was higher for female but not male double heterozygotes compared with single heterozygotes (FVL: 2.51, 95%CI 1.55-4.08, FIIG20210A: 1.75, 95%CI 1.14-2.68) and wildtype carriers (HR 2.53, 95%CI 1.58-4.05) but not compared with FVL homozygotes (HR 1.31, 95%CI 0.94-1.83). Female double heterozygotes developed VTE nearly a decade earlier than wildtype carriers and FVL heterozygotes (mean 44.2 vs. 52.6 and 52.2 years), most often in association with oral contraceptives. Spontaneous VTE and arterial thromboembolic events were not more frequent in double heterozygotes compared with the other genotype groups. Deep vein thrombosis (DVT) of the lower limb was the predominant VTE location in double heterozygotes, atypical vein thrombosis was rare. A phenomenon that has been described as the FVL paradox, a higher proportion of isolated DVT than pulmonary embolism, was also found for double heterozygotes.

CONCLUSION

The thrombotic phenotype in double heterozygotes resembles the appearance of the thrombotic phenotype in FVL carriers but the thrombotic risk is aggravated by women-specific risk factors.

Head and neck free tissue transfer in a patient with factor V Leiden: case report and review of the literature

Hypercoagulable disorders can compromise success of free flap reconstruction. Factor V Leiden is one such disorder for which only one previously reported case of successful free tissue transfer in the head and neck has been described. We report a 70-year-old woman with factor V Leiden treated for stage IVA squamous cell carcinoma of the mandible with a composite resection and reconstruction with an osteocutaneous scapular free tissue transfer. The free tissue transfer occurred without complications, in the setting of intraoperative heparin, postoperative aspirin, and enoxaparin. The free tissue transfer continues to be viable at her most recent follow-up appointment. The hypercoagulable patient represents a diverse presentation of increased coagulation risk in the perioperative period. Considering a patient's history and understanding available treatment adjuncts can factor heavily in a patient with factor V Leiden successfully undergoing free tissue transfer for head and neck defects.

Association of venous thromboembolism and myocardial infarction with Factor V Leiden and Factor II gene mutations among Libyan patients

Factor V Leiden G1691A (FVL) and Factor II prothrombin G20210A (PGM) mutations are the leading causes of thrombophilia. In this study, we have investigated the prevalence of the FVL G1691A and PGM G20210A single nucleotide polymorphisms (SNPs) among Libyan deep vein thrombosis (DVT) and myocardial infarction (MI) patients. SNP genotyping was performed using high-resolution melt analysis (HRM) and DNA sequencing. Biochemical parameters conducted on 112 males and 93 females showed no significant difference in means between the control group and the deep vein thrombosis and myocardial infarction groups. For Factor V Leiden, 40 samples were genotyped. Of the 40 samples, 6 (15.0%) of them were heterozygous and no one was homozygous. As for Factor II SNP, 59 samples were genotyped and only 2 (3.3%) were heterozygous. All the heterozygous samples showed 100% concordance between the HRM-PCR and DNA sequence analysis. Our study showed, for the first time, that both the FVL and PGM mutations are present among Libyan DVT and MI patients and that the FVL mutation is significantly associated with DVT but not with MI. However, our results do not support the association of PGM G20210A mutation with DVT or MI.

Anti-β2-glycoprotein I autoantibodies influence thrombin generation parameters via various mechanisms

INTRODUCTION

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterised by recurrent thrombotic events, pregnancy loss and thrombocytopenia and the presence of antiphospholipid antibodies (APL). The exact pathomechanism of APS is still unknown, thus we investigated the effect of anti-β₂-glycoprotein I (anti-β₂GPI) on thrombin generation in different plasma samples.

METHODS

For the separation of anti-β₂GPI IgG, overall 12 APS patients were selected. The criteria were the existence of lupus anticoagulant, and the presence of anti-CL and anti-β₂GPI, the latter exceeding at least 25 times the upper reference limit. We purified anti-β₂GPI IgG antibodies from APS patients by affinity chromatography and added the antibodies to normal pooled, and heterozygous forms of inherited thrombophilia plasma samples (prothrombin G20210A, factor V Leiden). To further specify the mechanism of the effect, we also used factor deficient plasmas in the thrombin generation assay.

RESULTS

In normal pooled plasma, the anti-β₂GPI significantly prolonged Lag Time according to the lupus anticoagulant effect, in contrast, it also elevated Peak Thrombin significantly, which suggests a procoagulant effect. The antibody was also able to exert this multi-faceted effect both in FV_Leiden heterozygous plasma and prothrombin G20210A heterozygous polymorphism, however, the prolonging effect was more remarkable in the latter. By using factor deficient plasmas, it was found that FVII is required for the prolongation, while intrinsic factors are needed for the elevation of the Peak Thrombin.

CONCLUSION

The anti-β₂GPI autoantibodies exert their effect in both normal and thrombophilic plasmas via various mechanisms.

Prevalence of Factor V Leiden in a healthy population in Santa Catarina, Southern Brazil

Thrombophilic disorders are found in 50% of patients with venous thromboembolism, and factor V Leiden (FVL) is the most common genetic risk factor for the development of these conditions. FVL prevalence varies according to population group. In Europe, many countries have a high prevalence of the mutation, including Portugal, Germany, and Italy. Santa Catarina State, southern Brazil, was colonized by different European nations; most inhabitants are descendants of Portuguese, Italian, and German immigrants. There are, however, no data on the prevalence of FVL in the state. This study aimed to determine FVL prevalence in a healthy population in Santa Catarina and assess whether there is an association between the mutation and demographic characteristics, thereby contributing to the understanding of the heterogeneity of prevalence of this important VTE risk factor and racial or geographical differences in the incidence of thrombotic diseases. Analysis of the FVL mutation was performed on 400 blood donors using the PCR technique followed by enzymatic digestion. The findings show that 2.5% of the participants were heterozygous for FVL, and none were homozygous. No association was found between the presence of FVL in heterozygosis and individual characteristics. In conclusion, this study found a prevalence of FVL in heterozygosis of 2.5% among healthy individuals in Santa Catarina, Brazil. Further studies are needed to assess the prevalence of FVL in other regions of the country, determine the distribution of the mutation among population groups, and evaluate how these factors affect the incidence of thrombotic diseases.

ARMS TaqMan real-time PCR for genotyping factor V Leiden mutation in Han Chinese

Factor V Leiden (FV_Leiden ) is a missense mutation of 1691 position (G1691A) in exon 10 of FV gene, and being a genetic risk for venous thrombosis. Currently, there are several PCR-based methods for detecting FV_Leiden mutation; however, these methods have disadvantages such as time-consuming, cumbersome steps and potentially hazardous gels. The aims of present study were to develop a simple, time-saving, accurate, and gel-free method, called amplification refractory mutation system (ARMS) TaqMan real-time PCR, for detecting FV_Leiden mutation. We severally designed two specific reverse primers for mutant and wild-type through intentional introduction of mismatched nucleotide at the penultimate 3' position. Although target amplicon amplification efficiency is reduced, but another corresponding amplicon is almost completely inhibited. Then, specific TaqMan-probe was designed to detect target amplicon. Established method was used to detect 500 unselected samples in Han Chinese, the results showed 499 cases of wild-type and one heterozygote. Afterward, 50 randomly picked wild-type cases and one heterozygote were reexamined by bidirectional DNA sequencing, which is considered as "Gold standard method." Exhilaratingly, the results detected by the two methods were completely consistent. At last, allelic frequency of FV_Leiden was calculated the in Han Chinese. Given the above results, A FV_Leiden heterozygote has been found in 500 random samples in Han Chinese, and the allelic frequency was 0.1%. In conclusion, the ARMS TaqMan real-time PCR is an ideal detecting system for genotyping FV_Leiden mutation in clinical application, and FV_Leiden mutation exists in Han Chinese despite extremely low prevalence.

Factor V Leiden 1691G > A mutation and the risk of recurrent pregnancy loss (RPL): systematic review and meta-analysis

Background

Although numerous replication case-control studies have attempted to determine the association between Factor V Leiden (FVL) 1691G > A mutation and susceptibility to Recurrent pregnancy loss (RPL), there have been confliction among the results of various ethnic groups. To address this limitation, here we implemented first meta-analysis to provide with consistent conclusion of the association between FVL 1691G > A mutation and RPL risk.

Methods

After a systematic literature search, pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were used to evaluate the strength of the association. Additionally, meta-regression analyses were performed to find potential source of heterogeneity.

Results

In this meta-analysis, 62 studies, containing 10,410 cases and 9406 controls, were included in quantitative analysis. Overall population analysis revealed a significant positive association in the dominant (OR = 2.15, 95% CI = 1.84-2.50, P < 0.001), over-dominant (OR = 1.88, 95% CI = 1.61-2.19, P < 0.001), allelic (OR = 2.05, 95% CI = 1.79-2.35, P < 0.001), and heterozygote (OR = 1.97, 95% CI = 1.68-2.30, P < 0.001) models. Moreover, a significant association of dominant (OR = 3.04, 95% CI = 2.04-4.54, P < 0.001), over-dominant (OR = 2.65, 95% CI = 1.74-4.05, P < 0.001), and heterozygote (OR = 2.67, 95% CI = 1.81-4.22, P < 0.001) models was found in the Iranian population. The subgroup analysis indicated strong significant association in Asian, European, Africa population, and case-control studies but not in South Americans and cohort studies.

Conclusion

The FVL 1691G > A mutation and the risk of RPL confers a genetic contributing factor in increasing the risk of RPL, particularly in Iranians, except for South Americans.

Loop-mediated isothermal amplification (LAMP)-based method for detecting factor V Leiden and factor II G20210A common variants

Automated methodologies allowing for rapid detection of Factor V Leiden and Factor II G20210A variants are desirable, due to a high number of tested patients. Here, we report a preliminary validation of a CE-marked in vitro diagnostic (IVD) certified method for simultaneous detection of Factor V Leiden and Factor II G20210A variants on whole blood samples. The novel method is based on Loop-mediated isothermal AMPlification (LAMP) applied for a duplex detection of Factor V Leiden and Factor II G20210A variants without requiring prior DNA extraction, whereas the routine one is a TaqMan SNP genotyping targeting genomic DNA. We tested routine patients for both variants using novel and current methods and estimated concordance rate. Patients were tested under similar laboratory procedures. One hundred and eight patients referred for the thrombophilia testing in the period between 9th December 2019 to 27th February 2020 represented the study population. We routinely identified for the Factor V Leiden variant 163 wild-type, 17 heterozygotes and no homozygote. Concerning the Factor II G20210A variant, we identified 170 wild-type, nine heterozygotes and one homozygous carrier. Two heterozygotes carried both variants (double heterozygotes). The LAMP method showed a 100% concordance rate, detecting rightly all genotypes. The LAMP for a duplex detection of common thrombophilia variants shows analytic performances as good as those of the standard method.

Interaction of thrombophilic SNPs in patients with unexplained infertility-multifactor dimensionality reduction (MDR) model analysis

PURPOSE

Our aim was to evaluate the frequency and SNP-SNP interactions between factor V Leiden (FVL) G1691A, prothrombin G20210A mutation, and C677T MTHFR and PAI-1 4G/5G gene polymorphisms in female IVF patients with unexplained infertility (UI) by using a multifactor dimensionality reduction (MDR) model analysis.

METHODS

A total of 225 subjects were enrolled in the study. There were 105 females in UI group and 120 healthy controls. Designated SNPs were determined by using allele-specific PCR methods. The difference in thrombophilia prevalence was assessed by a chi-square test and logistic regression analysis. Four-locus SNP interaction model was tested using the MDR approach. A ten-fold cross-validation consistency (CVC) and permutation testing were performed.

RESULTS

There was a significant difference of MTHFR C677T polymorphism frequency between the groups. Significantly less UI patients had MTHFR CC genotype (p = 0.005), while the risk allele T was more frequent (OR = 1.83, p = 0.0018). Logistic regression determined a significant association only for MTHFR C677T in our patients (TT genotype OR = 2.99). The MDR analysis confirmed the significance of a single-locus model for MTHFR C677T polymorphism (p = 0.015; OR = 2.93). However, the best, significant predictive model was the two-locus model comprising MTHFR C677T and FVL (CVC = 10/10, testing accuracy = 60.95%, p = 0.013; OR = 3.02).

CONCLUSION

The MTHFR C677T polymorphism was significantly associated with UI, with minor allele T being more frequent. Additionally, there was a significantly increased presence of MTHFR C677T with FVL mutation in these patients. Therefore, MTHFR and its interaction with FVL should be recognized as contributing factors in the pathogenesis of infertility.

Transient Familial Factor V Leiden-Linked Hip Osteoporosis

INTRODUCTION

Transient osteoporosis of the hip (THO) is a rare disease of unknown pathogenesis that has traditionally been considered an early and reversible stage of avascular necrosis (AN). Thrombophilia or familial hypofibrinolysis is considered a risk factor for the development of AN and THO. Factor V Leiden is one of the most common hereditary hypercoagulability disorders.

CLINICAL CASES

Case series study. The development and course of 3THO cases in 3siblings (two males and one female) aged between 40 and 43 years are described consecutively. Clinical and nuclear magnetic resonance imaging (MRI) studies confirmed the diagnosis of THO and ruled out the presence of AN. The G1691A mutation of factor v Leiden was positive in all cases. The clinical and radiological outcome was favourable, with healing without sequelae and disappearance of bone oedema on control MRI at 6 months in all cases.

DISCUSSION

The results of this study support the ischaemic aetiology and establish HTO as an early and reversable stage of hip AN. Factor V Leiden causes a state of hypercoagulability and hypofibrinolysis that encourages the development of THO due to ischaemic causes.

CONCLUSIONS

This study outlines the first familiar description of factor v Leiden-linked THO.

The association between activated protein C ratio and Factor V Leiden are gender-dependent

Background The most common cause of activated protein C (aPC) resistance is a missense substitution (Arg506Gln), known as Factor V Leiden (FVL). Due to its low cost, many laboratories use the aPC ratio as a primary test with a unisex cut-off. However, the association between the aPC ratio and FVL including any relation to gender has been sparsely investigated. Methods Results of the aPC ratio and FVL analyses from 1081 patients referred to the Thrombophilia Clinic at Odense University Hospital were compared. Results In 153 FVL positive patients, the mean aPC ratio was 2.1 ± 0.3, which differed from 2.7 ± 0.4 in FVL negative individuals (p < 0.01). The receiver operating characteristics (ROC), with area under the curve (AUC) of 0.93, indicated the optimal aPC cut-off at 2.3-2.4, with sensitivity 89%-94%, specificity 71%-84%, positive predictive value 35%-48% and negative predictive value 98%-99%. In FVL positive females, the mean aPC ratio was 2.0 ± 0.3, which differed from males (2.1 ± 0.3, p < 0.05). In FVL negative females, the mean aPC ratio was 2.6 ± 0.4, also different from males (2.8 ± 0.5, p < 0.01). Of note, 35% of FVL negative females had an aPC ratio ≤2.4 against 18% in males (p < 0.01). Conclusions Our results indicate that the aPC ratio is lower in females than in males. Due to a high negative predictive value the aPC ratio can be used as a first line test for FVL, but those found positive must be confirmed with a DNA test.

Simple Laboratory Test Utilization Interventions to Reduce Inappropriate Specialty Coagulation Testing

OBJECTIVES

The naming convention in coagulation may cause confusion in electronic ordering systems, leading to inappropriate test orders. We implemented test utilization efforts and studied utilization before and after interventions for two specialty coagulation assays.

METHODS

Two interventions were implemented: test names were changed from factor assay to activity, and residents reviewed all factor V and X requests. A retrospective review of factor V and X activity orders was performed for the period 1 year before and after interventions.

RESULTS

After interventions, factor V and X activity orders decreased by approximately 40%. Resulted tests decreased by 53.8% and 47.8%, corresponding to reductions of $2,493.05 and $1,867.80 per year in laboratory charges for factor V and factor X activity, respectively. Abnormal factor V activity results increased from 45% to 59%. Factor V activity orders from outpatient clinics decreased by 21.6%.

CONCLUSIONS

Simple interventions can reduce inappropriate specialty coagulation test orders and unnecessary costs.

Evaluation of Factor V Leiden and prothrombin G20210A mutations in Sudanese women with severe preeclampsia

BACKGROUND

Preeclampsia (PE) is a common pregnancy complication and one of the main causes of maternal and fetal morbidity and mortality, worldwide. While the pathogenesis of PE is unclear, it has been suggested that hypercoagulability due to Factor V Leiden (FVL) and prothrombin gene mutation (FII G20210A) play a role in its progression.

PURPOSE

This study aimed to determine if there is an association between FVL and FII G20210A mutations and severe PE.

PATIENTS AND METHODS

This case-control study enrolled 50 women with severe PE and 50 healthy pregnant women as the control, at Khartoum North Teaching Hospital, in Khartoum State, Sudan, from January 2017 to June 2017. The presence of point mutations in FVL and FII G20210A were determined for each of the participants. Deoxyribonucleic acid (DNA) was extracted, and then an allele-specific polymerase chain reaction (PCR) was used to detect the point mutations in FVL and FII G20210A.

RESULTS

The results revealed a significant difference between the subjects in the severe PE group and the control group for the means of parity, gestational age/ week and hemoglobin concentration (P < 0.05). No statistically significant body mass index (BMI) differences were found between the groups (P > 0.05). Women with severe PE were found to have a significant difference in FVL (16%; P value = 0.0058; OR: 20.20; 95%CI: 1.132-360.5) and FII G20210A (14%; P value = 0.0125; OR: 17.41; 95%CI: 0.9659-314.0) in comparison to the women in the control group (0%).

CONCLUSION

Our findings intensely indicate that there is a statistically proven significant association between FVL, FII G20210A mutations and the development of severe preeclampsia in Sudanese pregnant women.

New D-dimer threshold for Japanese patients with suspected pulmonary embolism: a retrospective cohort study

Background

In the diagnosis of pulmonary embolism (PE), the d-dimer threshold is based on studies conducted in Western countries, where the incidence rate is 5 times higher than that in Asian countries, including Japan. If we could elevate the d-dimer threshold based on the low pre-test probability in the Japanese population, we could omit the computed tomography pulmonary angiography (CTPA) which might lead to radiation exposure and contrast-induced nephropathy. Therefore, we aimed to determine a new d-dimer threshold specific to Japanese individuals.

Methods

We conducted a retrospective cohort study at an emergency department in Japan, using medical charts collected from January 2013 to July 2017. We included patients whose d-dimer were measured for suspicion of PE with low or intermediate probability of PE and CTPA were performed. The primary outcome was failure rate of the new d-dimer threshold, defined as the rate of PE detected by CTPA among patients with d-dimer under the new threshold ranging from 1000 to 1500 μg/L by 100. The new d-dimer threshold was appropriate if the upper limit of 95% confidence interval of the failure rate of PE was approximately 3%.

Results

In 395 patients included, the number of patients with PE was 24 (the prevalence was 6.1%). If the d-dimer threshold was 1100 μg/L, the failure rate was 0% (0/119), the upper limit of the 95% confidence interval of the failure rate was 3.1%, and 30% (119/395) of the CTPA might be omitted.

Conclusion

The new d-dimer threshold could safely exclude PE. This result can be generalized to other Asian populations with a lower incidence of PE. Further prospective studies will be needed.

Acute mesenteric ischemia in an African American patient with heterozygous factor V Leiden deficiency

It is well documented that factor V Leiden mutation (FVL) is a common hypercoagulable risk factor in the Caucasian population. Patients with homozygous FVL mutation have an increased risk for venous thromboembolism. However, there have been few cases of heterozygous FVL mutation associated with arterial thrombosis described in the literature. Our case report presents an African American (AA) female with heterozygous FVL mutation who presented with acute arterial mesenteric ischemia.

Isolated pulmonary embolism in a patient with progestin intrauterine device and factor V Leiden

The risk of venous thromboembolism (VTE) in patients using estrogen contraception is well known. However, the association of progestin-only contraception (POC) and the risk of thrombosis is poorly investigated. Few studies on this topic have failed to prove a significant increase in VTE in patients using POC, including patients with a medical condition associated with an increased risk of thrombosis. Therefore, no specific consideration is warranted when using a POC in healthy young females, regardless of an inherited thrombophilia. We present a case of a young woman who has Factor V Leiden (FVL), presenting with an isolated pulmonary embolism (PE) while using a progesterone containing intrauterine device (IUD). The risk of VTE in FVL carriers seems to outweigh the benefit of contraception even when using progestin-only contraception. Therefore, non-hormonal contraception, such as copper IUD, seems to be the only safe alternative for contraception in this population. Further studies are needed to elucidate this observation. Abbreviation: PE: pulmonary embolism; FVL: factor V Leiden; VTE: venous thromboembolism; POC: progestin only contraception; CBC: complete blood count; CMP: complete metabolic panel; ABG: arterial Blood gas; CTPA: CT pulmonary angiography.

Recurrent pregnancy loss: can factor V Leiden mutations be a cause

The role of Factor V Leiden (FVL) mutation in recurrent miscarriages has been disputed. It has been hypothesized that FVL mutation in patients with recurrent miscarriages is treatable. In this study, we evaluated 78 pregnant women for FVL mutations, among whom 50 had a history of recurrent miscarriages. Only 1 (2%) of the woman was positive for heterozygous FVL mutation. The incidence of FVL mutations in patients with recurrent pregnancy loss had an odds ratio of 1.72 (95% confidence interval, 0.0681–43.8257; P>0.05). However, the findings were not statistically significant. Thus, we suggest that FVL mutation study may not be included in the battery of tests for recurrent miscarriages in the Indian population.

Ischemic colitis due to antiphospholipid antibody syndrome

Introduction

Portal system ischemia may present insidiously which may aggravates the prognosis.

Case presentation

A 26-year old man presented with watery diarrhea and generalized abdominal pain for 3 months. On physical examination, moderate splenomegaly was noticeable. Stool exam and culture was negative except for blood in stool. Colonoscopy was in favor of inflammatory bowel disease although the patient symptoms have worsened despite treatment. Abdominopelvic computed tomography (CT) showed thromboses in portal and superior mesenteric veins and as the ill patient evolved signs of peritonitis, he underwent laparotomy during which, total colectomy was performed due to significant bowel necrosis. The cause of venous thrombosis of the portal system revealed to be Factor V Leiden and the presence of antiphospholipid syndrome.

Conclusion

High mortality rates of portal and mesenteric thromboses despite therapy urge the need for early clinical suspicion, careful assessment of the differential diagnoses and timely treatment for fewer adverse events. Although the therapeutic plan is challenging, anticoagulation, angiography and surgical resection increase survival.

SERPINC1 variants causing hereditary antithrombin deficiency in a Danish population

INTRODUCTION

Antithrombin deficiency is associated with increased risk of venous thromboembolism (VTE). We aimed to identify variants causing antithrombin deficiency in a Danish population.

MATERIALS AND METHODS

We performed Sanger sequencing and, in relevant cases, multiplex ligation-dependent probe amplification analyses, in 46 individuals (23 index cases) with and 9 relatives without antithrombin deficiency. Furthermore, in order to explore whether a combination of antithrombin type II heparin binding site (HBS) deficiency and factor V Leiden single nucleotide variant (SNV) conferred a higher risk of VTE than either risk factor alone, we performed genotyping for factor V Leiden in most of the carriers of type II HBS deficiency (n = 25).

RESULTS

We detected causal variants in all 46 carriers: three large and two small deletions, all causing type I antithrombin deficiency, and seven SNVs: one causing type I, one causing type II reactive site (RS), four causing type II HBS and one causing pleiotropic effect (PE) type II antithrombin deficiency. None of the relatives without antithrombin deficiency had the family variant. All detected SNVs have been reported previously. Majority (n = 27) of carriers had type II HBS deficiency, most often caused by the p.(Pro73Leu) SNV (n = 19). Heterozygosity for factor V Leiden was observed in three (3/25 = 12%) carriers of type II HBS deficiency. Only four (4/25 = 16%) carriers of type II HBS antithrombin deficiency experienced VTE, and two of these were heterozygous for factor V Leiden.

CONCLUSIONS

In a systematic search to identify variants causing hereditary antithrombin deficiency in a Danish population, we achieved a variant detection rate of 100%.

Direct blood PCR: TaqMan-probe based detection of the venous thromboembolism associated mutations factor V Leiden and prothrombin c.20210G>A without DNA extraction

BACKGROUND

Practically, the initial step of genetic analysis is the extraction of DNA from blood or other cells, which is often time consuming and cost-intensive. We aimed at establishing a real-time PCR protocol for the detection of the venous thromboembolism associated mutations factor V Leiden (F5 c.1691G>A; p.R506Q) and prothrombin (F2) c.20210G>A from whole blood, without DNA extraction.

METHODS

F5 c.1691G>A (p.R506Q) and F2 c.20210G>A mutations were determined in 205 EDTA anti-coagulated whole blood samples from patients who underwent routine clinical genotyping using the DirectBlood Genotyping PCR Kit (myPOLS Biotec, Konstanz, Germany) together with in-house developed TaqMan primer-probe assays.

RESULTS

Validity score values of genotype calls using whole blood were similar and did not significantly differ compared to those using genomic DNA as substrate in PCR. Mutation analysis of 205 whole blood samples showed a negligible PCR dropout rate (one in 410 reactions) and were in 100% concordance with results obtained by conventional genotyping.

CONCLUSION

We successfully established a robust and valid real-time PCR protocol for the detection of the venous thromboembolism associated mutations F5 c.1691G>A (p.R506Q) and F2 c.20210G>A directly from whole blood.

Genetics of Hypercoagulable and Hypocoagulable States

Hemostasis is the normal process of blood coagulation in vivo to stop pathologic bleeding. Virchow triad includes venous stasis, hypercoagulability, and vascular injury. Natural anticoagulants include protein C, protein S, and antithrombin. Factor V Leiden is the most common inherited thrombophilia, followed by prothrombin gene mutation. All inherited thrombophilias are passed down in an autosomal dominant fashion. Patients harboring the antiphospholipid antibodies have an increased risk for thrombosis. von Willebrand disease is the most common inherited bleeding disorder; the pattern of inheritance is autosomal. Hemophilia A and B are the only hereditary bleeding disorders inherited in a sex-linked recessive pattern.

Multiplex testing for Factor II and Factor V mutations in thrombophilia: technical verification and clinical validation of the cobas® Factor II and Factor V test

Laboratory testing for thrombophilia is complicated but essential for diagnosis. In 2017, the cobas® Factor II and Factor V Test (cobas F2F5 test) was launched for use with the cobas z 480 analyzer. This qualitative polymerase chain reaction test enables multiplex Factor II and Factor V testing with flexible reporting and workflow efficiency. Here, we report the results from studies investigating the performance of the cobas F2F5 test. Technical performance verification, clinical validation, external laboratory performance, and workflow comparison studies were performed. Fresh and frozen whole-blood and genomic DNA (gDNA) samples were tested, and several manual and automated DNA isolation methods were used. Bidirectional Sanger sequencing was used to verify genotypes identified by the cobas F2F5 test. One hundred percent agreement between the cobas F2F5 test and Sanger sequencing was observed for all genotypes. An external laboratory using remnant clinical samples also yielded 100% agreement between cobas F2F5 test results and their routine testing method. The cobas F2F5 test reduced the total sample processing time compared with the LightCycler® 1.2 platform (98.6 vs 420.2 min; 96 samples). Hemoglobin, extraction buffer, and ethanol contamination of the gDNA sample can lead to invalid results. The cobas F2F5 test has a high degree of accuracy for identification of Factor II and Factor V genotypes. This multiplex testing with short sample processing time can reduce handling errors and increase efficiency. Both manual and automated DNA isolation methods can be used with the cobas F2F5 test.

Prevalence of common hereditary risk factors for thrombophilia in Somalia and identification of a novel Gln544Arg mutation in coagulation factor V

Thrombophilia, commonly manifested as venous thromboembolism (VTE), is a worldwide concern but little is known on its genetic epidemiology in many parts of the globe particularly in the developing countries. Here we employed TaqMan genotyping and pyrosequencing to evaluate the prevalence of known common nucleotide polymorphisms associated with thrombophilia in a Somali population in the Puntland region of Somalia. We also employed next generation sequencing (NGS) to investigate other genetic variants in a Somali patient with deep venous thrombosis (DVT). As expected, we found no existence of factor V Leiden (rs6025) and prothrombin G20210A (rs1799963) in the Somali population. The G allele of ABO [261G/delG] polymorphism (rs8176719) was found at a frequency of 29%, similar to that observed in other African populations. We found the lowest so far reported frequency of MTHFR C677T (rs1801133) polymorphism in the Somali population (T allele frequency 1.5%). A novel and deleterious single nucleotide variation in exon 11 of coagulation factor V (c.1631A>G) causing Gln544Arg exchange in factor V was identified in a 29 years old Somali female with DVT. The same patient was heterozygous to VKORC1 Asp36Tyr polymorphism (rs61742245) that predisposes to warfarin resistance. In conclusion, this study shows that common hereditary factors for thromboembolism found in Caucasians are either less frequent or absent in the Somali population-similar to the situation in other Africans. NGS is possibly a better choice to detect genetic risk variants for thrombosis in this ethnic group.

Xanthine calculi in a patient with Lesch-Nyhan syndrome and factor V Leiden treated with allopurinol: case report

Background

Lesch-Nyhan syndrome is a rare inborn error of purine metabolism marked by a complete deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). Inherited as an X-linked recessive genetic disorder that primarily affects males, patients with Lesch-Nyhan syndrome exhibit severe neurological impairments, including choreoathetosis, ballismus, cognitive dysfunction, and self-injurious behavior. Uric acid levels are usually abnormally high, leading to kidney and bladder stones which often necessitate urological intervention. Factor V Leiden is an autosomal dominant disorder of blood clotting associated with hypercoagulability, thrombophilia, and renal disease.

Case presentation

We present the first reported case of xanthine calculi in a patient with Lesch-Nyhan syndrome and Factor V Leiden who was treated with allopurinol. A renal ultrasound and CT scan demonstrated bilateral staghorn calculi in the kidneys as well as nephrocalcinosis. Two years earlier the patient underwent cystoscopy with bilateral ureteroscopy and laser lithotripsy, and he was stone free afterwards. The patient subsequently underwent bilateral percutaneous nephrolithotomy (PCNL) and was stone free following the procedure. Patients with endogenous overproduction of uric acid who are being treated with allopurinol have a higher chance of developing xanthine stones.

Conclusions

Pediatricians treating these children should be aware of these rare conditions and promptly manage the potential complications that may require medical or surgical intervention.

High prevalence of factor V Leiden and prothrombin G20101A mutations in Kashmiri patients with venous thromboembolism

AIM

The genetic variants of the factor V (G1691A), prothrombin (G20210A) and MTHFR (C677T) genes have been widely implicated as inherited risk factors for developing venous thrombosis. This study was undertaken to reveal the frequency of these mutations in Kashmiri patients with venous thromboembolism.

METHODOLOGY

A case-control study was designed with 250 VTE patients and 250 healthy controls. The mutations were analysed using ARMS-PCR and PCR-RFLP approach.

RESULT

The factor V Leiden G1691A mutation was found in 17/250 (6.8%) VTE patients and prothrombin G20210A mutation was found in 7/250 (2.8%) VTE patients while no mutation was found in any of the healthy controls. Both the mutations were found to be significantly associated with the increased risk of VTE (p = 0.0001 and 0.0150 respectively) while no association of VTE risk with MTHFR C677T polymorphism was found (p = 0.53).

CONCLUSION

The increased frequency of factor V Leiden G1691A and prothrombin G20210A mutation in VTE patients indicates a significant role of these mutations in the development of VTE in our population. We therefore suggest the routine screening of these two mutations as thrombophilic markers in Kashmiri patients with venous thromboembolism.

Does exist a correlation between endometriosis and thrombophilic disorders? A pilot study

OBJECTIVE

At present, there is growing evidence of the existence of a genetic predisposition in both thrombophilic disorders and endometriosis. The aim of our study was to evaluate for the first time the prevalence of some thrombophilic disorders in patients with endometriosis.

MATERIALS AND METHODS

We conducted a retrospective study on 138 patients with endometriosis and 278 healthy control women. All women were subjected to a blood examination testing for thrombophilic screening and the variables examinated were: hyperhomocysteinemia, factor V Leiden and factor II prothrombin G20210A mutations in heterozygosis and homozigosis.

RESULTS

A significant reduced prevalence (p < 0.05) of factor V Leiden mutation in endometriosis patients was found, whereas no significant differences (p = NS) for factor II and hyperhomocysteinemia were observed.

CONCLUSION

Our preliminary data do not show any association between thrombophilic condition and endometriosis. Before assuming hormonal therapies, a thrombophilic plasmatic screening seems to be unnecessary in patients affected by endometriosis.

Factor V Leiden G1691A and prothrombin G20210A mutations among Palestinian patients with sickle cell disease

Background

Vascular thrombosis is an important pathophysiological aspect of sickle cell disease (SCD). This study aimed to investigate the prevalence and clinical impact of factor V Leiden G1691A (FVL) and prothrombin G20210A mutations among Palestinian sickle cell disease (SCD) patients.

Methods

A total of 117 SCD patients, including 59 patients with sickle cell anemia (SS), 33 patients with sickle β-thalassemia and 25 individuals with sickle cell trait (AS) were studied. The control group consisted of 118 healthy individuals. FVL and prothrombin G20210A mutations were determined by RFLP PCR.

Results

Analysis of the clinical history of SCD patients revealed that seven patients have had vascular complications such as ischemic stroke or deep vein thrombosis. In SCD patients, the inheritance of the FVL mutation showed a significantly higher incidence of pain in joints, chest and abdomen as well as regular dependence on blood transfusion compared to SCD with the wild type. Age- and sex-adjusted logistic regression analysis revealed a significant association between FVL and sickle cell anemia with an odds ratio (OR) of 5.6 (95% confidence intervals [CI] of 1.91–39.4, P = 0.039) in SS patients. However, increased prevalence of the FVL in AS subjects and sickle β-thalassemia patients was not statistically significant compared to controls (OR 3.97, 95% CI 0.51–28.6, P = 0.17 and OR 3.59, 95% CI 0.35–41.6, P = 0.26, respectively). The distribution of prothrombin G20210A mutation among SCD patients compared to controls was not significantly different, thus our findings do not support an association of this mutation with SCD.

Conclusions

FVL was more prevalent among SS patients compared to controls and it was associated with higher incidence of disease complications among SCD patients.

Investigation of methylenetetrahydrofolate reductase C677T and factor V Leiden mutation as a genetic marker for retinal vein occlusion

PURPOSE:

Thromboembolic phenomenon is one of the causes of retinal vein occlusion (RVO) which is in fact a multifactorial disease. Therefore, we aimed to study methylenetetrahydrofolate reductase gene polymorphism (MTHFR C677T) and factor V Leiden as genetic risk factors of RVO.

MATERIALS AND METHODS:

A total of 50 (19 males and 31 females) cases of RVO were compared with 50 age- and sex-matched (21 males and 29 females) controls. Complete ocular examination was done for all samples. The diagnosis of RVO was made clinically; however, fundus fluorescein angiography and optical coherence tomography were performed when needed. Serum homocysteine levels were estimated by automatic chemiluminescence analyzer, whereas MTHFR C677T and factor V Leiden mutations were detected by polymerase chain reaction–restriction fragment length polymorphism method.

RESULTS:

The mean age of RVO cases and controls was 54.62 ± 13.92 years and 58.72 ± 11.20 years, respectively. 48.3% of cases and 51.7% of controls were diabetic. 65.3% of cases were hypertensive proving hypertension as a strong risk factor (P = 0.003) of RVO. Serum homocysteine was also found significantly high (P = 0.025) with mean values of 19.98 ± 9.03 μmol/L and 16.98 ± 8.29 μmol/L in cases and controls, respectively. The MTHFR genotype (CT) was found in 83.3% patients of central RVO group and 78.6% cases of branch RVO group that was significantly associated with high serum homocysteine levels. Factor V Leiden mutation was absent in all individuals.

CONCLUSION:

Hyperhomocysteinemia is an important risk factor for RVO, especially in patients with MTHFR C677T gene polymorphism.

Sensitized mutagenesis screen in Factor V Leiden mice identifies thrombosis suppressor loci

Factor V Leiden (F5^L ) is a common genetic risk factor for venous thromboembolism in humans. We conducted a sensitized N-ethyl-N-nitrosourea (ENU) mutagenesis screen for dominant thrombosuppressor genes based on perinatal lethal thrombosis in mice homozygous for F5^L (F5^L/L ) and haploinsufficient for tissue factor pathway inhibitor (Tfpi^+/- ). F8 deficiency enhanced the survival of F5^L/LTfpi^+/- mice, demonstrating that F5^L/LTfpi^+/- lethality is genetically suppressible. ENU-mutagenized F5^L/L males and F5^L/+Tfpi^+/- females were crossed to generate 6,729 progeny, with 98 F5^L/LTfpi^+/- offspring surviving until weaning. Sixteen lines, referred to as "modifier of Factor 5 Leiden (MF5L1-16)," exhibited transmission of a putative thrombosuppressor to subsequent generations. Linkage analysis in MF5L6 identified a chromosome 3 locus containing the tissue factor gene (F3). Although no ENU-induced F3 mutation was identified, haploinsufficiency for F3 (F3^+/- ) suppressed F5^L/LTfpi^+/- lethality. Whole-exome sequencing in MF5L12 identified an Actr2 gene point mutation (p.R258G) as the sole candidate. Inheritance of this variant is associated with suppression of F5^L/LTfpi^+/- lethality (P = 1.7 × 10^-6), suggesting that Actr2^p.R258G is thrombosuppressive. CRISPR/Cas9 experiments to generate an independent Actr2 knockin/knockout demonstrated that Actr2 haploinsufficiency is lethal, supporting a hypomorphic or gain-of-function mechanism of action for Actr2^p.R258G Our findings identify F8 and the Tfpi/F3 axis as key regulators in determining thrombosis balance in the setting of F5^L and also suggest a role for Actr2 in this process.

Diagnostic Testing Approaches for Activated Protein C Resistance and Factor V Leiden: A Comparison of Institutional and National Provider Practices

OBJECTIVES

To analyze the economic impact of testing for activated protein C resistance (APC-R) due to factor V Leiden (FVL) mutation with APC-R with reflexive FVL genotyping (algorithmic approach) or genotyping alone.

METHODS

OptumLabs Data Warehouse (OLDW) data were used to assess testing approaches. Insurance claims for APC-R and FVL in 2013 were compared with the Mayo Clinic database. Centers for Medicare & Medicaid Services diagnostic fee schedules were used to assign costs.

RESULTS

Of 19.3 million OLDW-covered individuals, 74,242 (0.385%) received 75,608 tests: APC-R, 2,265 (2.9%); FVL genotyping, 70,619 (90.1%); and both APC-R and FVL, 2,724 (7.0%). In total, 1,317 tests were performed at Mayo Clinic: APC-R with reflex FVL (1,256; 95.4%) and FVL alone (61; 4.6%). Costs per evaluated individual and per total population (person/year) in OLDW and algorithmic approach were $83.77 vs $36.38 and $0.32 vs $0.14, respectively.

CONCLUSIONS

The cost-optimized algorithmic approach reduces health care costs.

A Case Series of Young Patients with Completely Reversed Severe Pulmonary Hypertension

Pulmonary Arterial Hypertension (PAH) is a progressive symptomatic disorder, which may ultimately lead to death if left untreated. Although majority of PAH cases are idiopathic, pulmonary hypertension resulting due to certain underlying conditions are also observed frequently. In such cases, it becomes essential to identify any potentially treatable or reversible causes for PAH. There have been significant advances in the medical management of PAH and various medicines have been approved by US Food and Drug Administration (FDA) for various stages of PAH. With these therapies, there can be varying degrees of improvement in the pulmonary artery pressures and hemodynamic profile. Therefore, physiologic reversal can and does occur, sometimes to the point of normalization. We hereby present three such cases of severe PAH in patients below 50 years of age due to various aetiologies like left heart disease, isolated unilateral absence of right pulmonary artery with hypoplastic right lung and factor V Leiden mutation associated pulmonary thromboembolism, all of whose pulmonary artery pressures are completely normalised with adequate treatment of the underlying disease and with optimised medications for PAH, ultimately leading to tapering and stoppage of PAH medications.

Gender-related differences in the outcome of patients with venous thromboembolism and thrombophilia

BACKGROUND

In patients with venous thromboembolism (VTE) and factor V Leiden (FVL) or prothrombin 20210G-A mutation (PTM), the influence of gender on outcome has not been consistently studied.

METHODS

We used the RIETE (Registro Informatizado Enfermedad TromboEmbolica) database to assess the existence of gender differences in the rate of VTE recurrences (deep vein thrombosis [DVT] or pulmonary embolism [PE]) or major bleeding during the course of anticoagulation and after its discontinuation in FVL and PTM carriers.

RESULTS

From March 2001 to September 2016, 11,224 VTE patients underwent thrombophilia testing. Of these, 1,563 were FVL carriers (863 men and 700 women) and 1,231 were PTM carriers (659 men and 572 women). During the course of anticoagulant therapy, men with FVL had a 6-fold higher rate of VTE recurrences than major bleeds (31 vs. 5 events). In women with FVL, the rate of VTE recurrences was 2-fold higher (16 vs. 8), as was in men (17 vs. 8) or women (17 vs. 9) with PTM. After discontinuing anticoagulation, men with FVL had a 3-fold higher rate of DVT recurrences than women (hazard ratio [HR]: 3.13; 95% CI: 1.79-5.67), with no differences in PE recurrences. Among patients with PTM, there were no gender differences in the rate of DVT (HR: 1.89; 95% CI: 1.00-3.65) or PE recurrences (HR: 1.82; 95% CI: 0.83-4.12).

CONCLUSIONS

During the anticoagulation course, men with FVL are at a much higher risk for VTE recurrences than bleeding. After discontinuing anticoagulation, men with FVL are at an increased risk for DVT recurrences.