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Genotype and allele frequencies for thrombogenic mutations in the general Greek Cypriot population
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This study was performed to establish the allele, genotype and genotype combination/SNP (single nucleotide polymorphism) profile frequencies in the general population of Cyprus for 6 genes implicated in thrombotic disorders. The genes with their respective functional polymorphisms were the following: factor V (G1691A), prothrombin/factor II (G20210...
Citations
... Is it main-ly of ethnic origin, is it a consequence of population mixture or migration during history? Or, is it a founder effect depending on our search, study design and exploratory methods (14)(15)(16)? There are still many unanswered questions (Table II). ...
Introduction. In search for explanations of the clinical heterogeneity in patients with haemophilia (PwH) with the same mutation or degree of factor VIII deficiency, the coexistence of single or associated prothrombotic risk mutations has been widely evaluated. Objective. The evaluation of the frequency of prothrombotic risk mutations and polymorphisms in PwH in comparison with the general population. Method. The study was performed on 113 consecutive PwH consisting of PCR technology aiming to detect: factor V Leiden - G 1691A (FVL) and prothrombin (PT) - G 20210 A mutations, methylentetrahydrofolat - reductase (MTHFR) and plasminogen activator inhibitor type 1 (PAI-1) polymorphisms. Results. Within the whole study group, 52.21% patients have been identified with associated prothrombotic risk mutations or polymorphisms, 40.70% with one and 7.08% without any such alterations. The global frequency was characterized by the predominance of PAI-1 polymorphism present in 82.29% and MTHFR in 52.21% of patients. Heterozygous variants of PT G20210A, FV G1691A, MTHFR and PAI-1 were found in 7.96%, 9.73%, 39.82% and 53.98% cases, respectively. According to the disease severity, in 89 patients with severe hemophilia, the following frequencies of polymorphisms were found: for MTHFR 52.80%, for FV G1691A 5.61%, for PT G20210A 8.99% and for PAI-1 polymorphism 79.77%. Conclusions. The frequency of FV, PT and PAI-1 genes alterations in our group of hemophilia patients is higher than in the normal population. Nevertheless, considering their uneven distribution in different ethnic groups and geographical regions, more studies on a larger age- and sex-matched patient population are needed.
... Several studies have shown that all FV Leiden carriers share one and the same FV gene haplotype [8,64,[110][111][112], which suggests that they have The data have been extracted from the following sources: Albania [202], Austria [203], Azerbaijan [204], Belarus [205], Bulgaria [206], Croatia [207], Cyprus [64,208], Denmark [209], Finland [210], France [211][212][213], Germany [214,215], Greece [216], Holland [217], Hungary [218], Iceland [219], Ireland [220], Italy [221,222], Macedonia [202], Norway [223], Poland [224], Portugal [225], Serbia [226], Slovakia [227], Spain [228,229], Sweden [230,231], Turkey [232,233], and United Kingdom [234]. ...
This chapter describes some of the strategies developed in our group for designing, constructing and structurally and functionally characterizing tethered bimolecular lipid membranes (tBLM). We introduce this platform as a novel model membrane system that complements the existing ones, for example, Langmuir monolayers, vesicular liposomal dispersions and bimolecular ("black") lipid membranes. Moreover, it offers the additional advantage of allowing for studies of the influence of membrane structure and order on the function of integral proteins, for example, on how the composition and organization of lipids in a mixed membrane influence the ion translocation activity of integral channel proteins. The first strategy that we introduce concerns the preparation of tethered monolayers by the self-assembly of telechelics. Their molecular architecture with a headgroup, a spacer unit (the "tether") and the amphiphile that mimics the lipid molecule allows them to bind specifically to the solid support thus forming the proximal layer of the final architecture. After fusion of vesicles that could contain reconstituted proteins from a liposomal dispersion in contact to this monolayer the tethered bimolecular lipid membrane is obtained. This can then be characterized by a broad range of surface analytical techniques, including surface plasmon spectroscopies, the quartz crystal microbalance, fluorescence and IR spectroscopies, and electrochemical techniques, to mention a few. It is shown that this concept allows for the construction of tethered lipid bilayers with outstanding electrical properties including resistivities in excess of 10 MOmega cm2. A modified strategy uses the assembly of peptides as spacers that couple covalently via their engineered sulfhydryl or lipoic acid groups at the N-terminus to the employed gold substrate, while their C-terminus is being activated afterward for the coupling of, for example, dimyristoylphosphatidylethanol amine (DMPE) lipid molecules via the NH2 moiety of their headgroups. It is demonstrated that these membranes are well suited for the in situ synthesis of membrane protein by a cell-free expression approach. The vectorial integration of an in vitro synthesized odorant receptor, OR5 from the rat, is demonstrated by means of antibodies that specifically bind to a tag at the N-terminus of the receptor and is read out by surface plasmon fluorescence spectroscopy. A completely different strategy employs his-tagged membrane proteins in their solubilized form binding to a surface-attached Ni(+)-NTA monolayer generating a well-oriented protein layer the density of which can be easily controlled by online monitoring the binding (assembly) step by surface plasmon spectroscopy. Moreover, the attachment of the his-tag to either the C- or the N-terminus allows for the complete control of the protein orientation. After the exchange of the detergent micelle by a lipid bilayer via a surface dialysis procedure an electrically very well isolating protein-tethered membrane is formed. We show that this "wiring" of the functional units allows for the (external) manipulation of the oxidation state of the redox-protein cytochrome c Oxidase by the control of the potential applied to the gold substrate which is used as the working electrode in an electrochemical attachment.
... 165,166 The Factor V Leiden allele frequency in a random population in Greece (2.5-2.7%) is lower than that in Cyprus (4-7%). 162,168,169,179 Another study in the Greek population reported a frequency of 2.4% in controls and 16% in patients with DVT. 167 APC resistance was found to be present in 21% of women with recurrent abortions compared to 12% in normal pregnancies. ...
... This mutation has an allele frequency of 1.3-2.2% in the general population of Greece and 2-3.9% in Cyprus. 162,168,169,179 In Greece, the frequency of this mutant allele in patients with DVT (3.4%) was significantly higher than in controls (1.3%). 169 Southern Italian allele frequencies were 7.1% for DVT cases and 2.2% for the general population. ...
Thrombophilia is the term now used to describe predisposition to increased risk of venous and occasionally arterial thromboembolism due to hematological abnormalities. It can be a multifactorial disorder where congenital defects of anticoagulant or procoagulant factors may be combined with acquired hematological abnormalities. It should be considered in patients with a documented unexplained thrombotic episode or a positive family history. The aim of this document is to provide guidelines for investigation and management of patients with thrombophilia in the presence or absence of venous thromboembolism (VTE).
Congenital prothrombin deficiency is an extremely rare hemorrhagic disorder with estimated prevalence of 1 per 2,000,000 in the general population. Since the disorder is an autosomal recessive disorder, the disorder is more frequent in areas with high rate of consanguinity. Clinical manifestations of disorder are highly variable ranging from mild bleeding episodes to severe life-threatening hemorrhages. The disorder can be diagnosed based on routine and specific tests. No specific factor II concentrate is available, but patients can receive fresh frozen plasma and prothrombin complex concentrate (PCC). Traditionally patients with prothrombin deficiency receive on-demand therapy, but secondary prophylaxis can be used for those patients with high risk of severe life-threatening bleeding. With timely diagnosis and appropriate management of disorder, the quality of life in these patients can significantly improve.
Keywords: Prothrombin deficiency, Clinical manifestations, Diagnosis, Treatment
Coronary artery bypass grafting is one of the most common surgeries performed among all elective cardiac surgery operations. Starting from the first operations, thrombosis not only in the coronary arteries, but also in the venous system was the subject of attention. Over the past two decades it has become evident that the hypercoagulable state, or socalled thrombophilia is multifactorial, genetically determined disorder of the hemostatic system. This article provides an overview of studies on the role of genetic polymorphisms in the development of thrombosis after coronary artery bypass grafting.
Distribution of hereditary thrombophilic gene mutations differs globally. Prothrombin gene mutation G20210A is a common prothrombotic single-nucleotide polymorphism. In this systematic review, we provide a comprehensive report of the prevalence of prothrombin G20210A across the globe. Databases [Pubmed, Web of Science, Embase] were interrogated from their inception through December 2015 for articles reporting prothrombin G20210A prevalence rates and ethnicity. Prevalence rates were organized by continent and ethnoracial ancestry. A total of 113 articles were included with a total 61 876 participants tested for prothrombin G20210A. Reported prevalence rates varied from 0 to 15.9% among ethnic groups, with higher rates seen in the thromboembolism affected cohort compared with the unaffected cohort. Carrier rate distribution is supported by known historical migration patterns of global populations. This review of prothrombin G20210A prevalence may guide resourceful screening for identification of hereditary thrombophilia in female populations of interest with hypercoagulable states.
Activated protein C (APC) proteolytically inactivates factors Va (FVa) and VIIIa (FVIIIa), which in turn control two key steps of the coagulation cascade. The pathophysiological importance of this anticoagulant mechanism is illustrated by the severe prothrombotic diathesis associated with the congenital deficiencies of protein C and its cofactor protein S. A poor anticoagulant response of plasma to APC (APC resistance) was first described in a thrombotic patient in 1993 and soon recognized as the most common risk factor for venous thrombosis. The underlying genetic defect was identified one year later as the FV Arg506Gln mutation (FV Leiden), which abolishes one of the APC-cleavage sites on FVa. These ground-breaking discoveries have stimulated numerous researches into the workings of the proteinC pathway, the molecular mechanisms of APC resistance in carriers and noncarriers of FV Leiden, and the clinical significance of APC resistance. This chapter reviews the most important findings, summarizes the state of the art, and discusses new developments in this rapidly evolving research area.
Genetic association studies have revealed a correlation between DNA variations in genes encoding factors of the haemostatic system and thrombosis-related disease. This study investigated the prevalence of 13 such genetic risk factors in a sample (N=400 alleles) of the Hellenic population of Greece. Some of these polymorphisms [coagulation factor V (F5) Leiden, coagulation factor II (F2) G20210A, 5,10-methylene tetrahydrofolate reductase (MTHFR) C677T, coagulation factor XIII A1 subunit (F13A1) Val34Leu, serpine1 (SERPINE1) 4G/5G, angiotensin I-converting enzyme (ACE) I/D, angiotensinogen (AGT) Met325Thr, integrin A2 (ITGA2) C807T] have been previously studied in Hellenic populations of Greece and Cyprus, while others such as coagulation factor XII (F12) C46T, plasma carboxypeptidase B2 (CPB2) C1040T, platelet glycoprotein Ib α polypeptide (GP1BA) VNTR, thrombomodulin (THBD) -A33G and protein Z (PROZ) - A13G have not. Most of the allelic frequencies observed are similar to those reported for other Southern European populations. Knowledge of the prevalence of these variations in a given population may assist in the design of effective preventive measures against cardiovascular disease.
There are many genetic and acquired risk factors that are known to cause venous thromboembolic disorders (VTE). One of these is the Prothrombin G20210A mutation, which has been identified in 1996. Prothrombin G20210A mutation causes higher levels of the clotting factor prothrombin in the blood of carriers, which creates a higher tendency towards blood clotting (hypercoagulability), and therefore the carriers become at higher risk of developing VTE. High prevalence of Prothrombin G20210A mutation was reported in Caucasian populations, but the prevalence was almost absent in non-Caucasians. That was most obvious in countries of South Europe and the Mediterranean region. This review article discusses Prothrombin G20210A mutation, how it causes VTE, the origin of the mutation, and its distribution worldwide with special concentration on the Mediterranean area.
To determine the risk of an association with some genetic polymorphisms involved in venous thromboembolism (VTE) gene variations (FVL, FV H1299R, FII G20210A, MTHFR C677T, MTHFR A1298C, PAI-1 4G/5G, β-fibrinogen -455 G → A, FXIII Val34Leu and GpIIIa HPA-1a) in cancer patients.
Among 78 cancer patients, 28 who had proven first episode of VTE were selected as the patient group, with 50 control samples selected from age-, sex- and body mass index-matched healthy volunteers (healthy group). The differences in frequency of genetic polymorphisms were found to be statistically insignificant between these two groups.
Logistic regression analysis after adjustment for age, sex, smoking and hypertension showed no difference. The screened mutations of these genes were not significantly associated with VTE risk.
There is no possible benefit from genetic screening tests regarding VTE in cancer patients.
