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Seminars in Thrombosis and Hemostasis Mar 2022The congenital dysfibrinogenemias, most often associated with bleeding disorders, encompass mutations in the amino-terminal end of fibrinogen α-chain consisting of... (Review)
Review
The congenital dysfibrinogenemias, most often associated with bleeding disorders, encompass mutations in the amino-terminal end of fibrinogen α-chain consisting of Gly17-Pro18-Arg19-Val20, known as knob A, which is a critical site for fibrin polymerization. Here we review the studies reporting dysfibrinogenemia due to mutations affecting fibrinogen knob A and identified 29 papers. The number of reports on dysfibrinogenemias related to residues Gly17, Pro18, Arg19, and Val20 is 5, 4, 18, and 2, respectively. Dysfibrinogenemias related to residues Gly17, Pro18, and Val20 are exclusively associated with bleeding tendency. However, the clinical picture associated with dysfibrinogenemia related to residue Arg19 varies, with most patients suffering from bleeding tendencies, but also transitory ischemic attacks and retinal thrombosis may occur. The reason for this variation is unclear. To elaborate the genotype-phenotype associations further, we studied a Danish family with knob A-related dysfibrinogenemia caused by the Aα Arg19Gly (p.Arg19Gly) mutation using whole-exome sequencing and fibrin structure analysis. Our family is the first reported carrying the p.Arg19Gly mutation combined with one or more single nucleotide polymorphisms (SNP)s in , , and/or and increased fibrin fiber thickness and fibrin mass-to-length ratio suffering from pulmonary emboli, suggesting that compound genotypes may contribute to the thrombogenic phenotype of these patients. Our review, accordingly, focuses on significance of SNPs, compound genotypes, and fibrin structure measures affecting the genotype-phenotype associations in fibrinogen knob A mutations.
Topics: Afibrinogenemia; Fibrinogen; Genotype; Hemorrhage; Humans; Thrombosis
PubMed: 34261148
DOI: 10.1055/s-0041-1730358 -
Thrombosis Research Sep 2022Ranging from bleeding to thrombosis, the clinical features of congenital fibrinogen qualitative disorders, including dysfibrinogenemia and hypodysfibrinogenemia, are... (Review)
Review
Ranging from bleeding to thrombosis, the clinical features of congenital fibrinogen qualitative disorders, including dysfibrinogenemia and hypodysfibrinogenemia, are highly heterogeneous. Although the associations between some specific fibrinogen mutations and the thrombotic phenotypes have been well elucidated, the underlying mechanism between fibrinogen variants and bleeding events remains underestimated. After systematically reviewing the literature of (hypo-)dysfibrinogenemia patients with bleeding phenotypes, we identified several well-characterized bleeding-related fibrinogen variants in those patients. Several possible pathomechanisms are proposed to explain the genotype-phenotype associations: 1, mutations in the NH-terminal portion of the Aα chain hamper fibrinogen fitting into the active site cleft of thrombin and drastically slow the conversion of fibrinogen into monomeric fibrin; 2, mutations adding new N-linked glycosylation sites introduce bulky and negatively charged carbohydrate side chains and undermine the alignment of fibrin monomers during polymerization; 3, mutations generating unpaired cysteine form extra disulfide bonds between the abnormal fibrinogen chains and produce highly branched and fragile fibrin networks; 4, truncation mutations in the fibrinogen αC regions impair the lateral fibril aggregation, as well as factor XIII crosslinking, endothelial cell and platelet binding. These established relationships between specific variants and the bleeding tendency will help manage (hypo-)dysfibrinogenemia patients to avoid adverse bleeding outcomes.
Topics: Afibrinogenemia; Blood Coagulation Tests; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Hemorrhage; Humans; Thrombosis
PubMed: 35853369
DOI: 10.1016/j.thromres.2022.07.005 -
Clinica Chimica Acta; International... Mar 2022Congenital dysfibrinogenemia is characterized by qualitatively abnormal fibrinogens with resultant blood coagulation dysfunction. The clinical manifestations are high... (Review)
Review
BACKGROUND
Congenital dysfibrinogenemia is characterized by qualitatively abnormal fibrinogens with resultant blood coagulation dysfunction. The clinical manifestations are high heterogeneity. Treatment for dysfibrinogenemia should be personalized. Here, we reported four congenital dysfibrinogenemia patients with the major surgery, in order to discuss the treatment and diagnosis of congenital dysfibrinogenemia.
METHODS
We reported four asymptomatic congenital dysfibrinogenemia patients with the major surgery (valve replacement, brain surgery, tumorectomy, hysterectomy) in our study. Routine coagulation tests, hepatorenal function and gene analysis, thrombelastogram were performed.
RESULTS
Four congenital dysfibrinogenemia patients all showed prolonged TT, low level of activity fibrinogen and normal fibrinogen antigen. Case1 showed a heterozygous mutation in exon 2 of the FGA, c.1223G > C, which turns the codon for residue Aα Gly13 into Arg (p. Gly13Arg). DNA sequencing of case2 showed that a heterozygous mutation in exon 8 of the FGG (c.5877G > A) with being responsible for the Arg → His substitution at position 301 of the γ chain (p. Arg301His). Case3 and case 4 failed to do genetic testing for other reason. Four congenital dysfibrinogenemia patients were asymptomatic in the daily life. Personal and family history revealed no abnormal bleeding or thrombotic events. These four patients did not receive special treatment and management before surgery. They all had a smooth operation.
CONCLUSIONS
Misdiagnosis and unnecessary infusion bring huge health risks to patients. Correct diagnosis of congenital dysfibrinogenemia is the key to avoid misdiagnosis or unnecessary infusion. Asymptomatic patients with congenital dysfibrinogenemia do not need cryoprecipitate or fibrinogen input before major surgery.
Topics: Afibrinogenemia; Blood Coagulation Tests; Female; Fibrinogen; Fibrinogens, Abnormal; Humans; Sequence Analysis, DNA
PubMed: 35063457
DOI: 10.1016/j.cca.2022.01.009 -
Seminars in Thrombosis and Hemostasis 1999Congenital abnormal fibrinogen molecules (dysfibrinogenemias) are due to structural defects in the molecule. The molecular structure of the fibrinogen molecule is to a... (Review)
Review
Congenital abnormal fibrinogen molecules (dysfibrinogenemias) are due to structural defects in the molecule. The molecular structure of the fibrinogen molecule is to a great extent known and this has allowed identification of the abnormalities at a molecular level. While most patients with dysfibrinogenemia are clinically asymptomatic, some present with a bleeding diathesis, others with thrombophilia, and occasionally with both, bleeding and thromboembolism. In principle, the dysfibrinogenemias are due to either impaired release of the fibrinopeptides, defective fibrin polymerization, or abnormal cross-linking by factor XIIIa. Dysfibrinogenemias associated with thrombophilia have been reported in those related to abnormal fibrinopeptide release or defective polymerization. In addition, abnormal interactions with platelets, defective fibrinolysis, defective assembly of the fibrinolytic system, and abnormal calcium binding have been described. The presently identified dysfibrinogenemias associated with thrombosis and their molecular defects are described in this review. It must also be recognized that some patients with abnormal fibrinogen molecules have additional hemostasis defects, such as abnormalities of antithrombin, protein C, protein S, factor V Leiden, and others. On rare occasions, dysfibrinogenemias can be associated with hypofibrinogenemia.
Topics: Fibrinogens, Abnormal; Humans; Thrombophilia; Thrombosis
PubMed: 10443961
DOI: 10.1055/s-2007-994933 -
Research and Practice in Thrombosis and... Aug 2021Hypodysfibrinogenemia (HD) is a heterogeneous disorder in which plasma fibrinogen antigen and function are both reduced but discordant. This report addresses the key...
Hypodysfibrinogenemia (HD) is a heterogeneous disorder in which plasma fibrinogen antigen and function are both reduced but discordant. This report addresses the key clinical question of whether genetic analysis enables clinically useful subclassification of patients with HD. We report a new case and identify a further eight previously documented cases that have the laboratory features of HD but biallelic inheritance of quantitative and qualitative fibrinogen gene variants. The cases displayed both bleeding and thrombosis and sometimes had undetectable fibrinogen activity. In all cases, the predicted effect of the coinherited variants is reduced levels of circulating fibrinogen that is all dysfunctional. We propose the term for this subtype of recessively inherited HD that is distinct from the more commonly recognized monoallelic HD caused by a single fibrinogen gene variant.
PubMed: 34458664
DOI: 10.1002/rth2.12568 -
Archives of Pathology & Laboratory... Nov 2002To review the state of the art relating to congenital dysfibrinogenemia as a potential risk factor for thrombosis, as reflected by the medical literature and the... (Review)
Review
OBJECTIVES
To review the state of the art relating to congenital dysfibrinogenemia as a potential risk factor for thrombosis, as reflected by the medical literature and the consensus opinion of recognized experts in the field, and to make recommendations for the use of laboratory assays for assessing this thrombotic risk in individual patients.
DATA SOURCES
Review of the medical literature, primarily from the last 10 years.
DATA EXTRACTION AND SYNTHESIS
After an initial assessment of the literature, key points were identified. Experts were assigned to do an in-depth review of the literature and to prepare a summary of their findings and recommendations. A draft manuscript was prepared and circulated to every participant in the College of American Pathologists Conference on Diagnostic Issues in Thrombophilia. Each of the key points and associated recommendations were then presented for discussion at the conference. Recommendations were accepted if a consensus of experts attending the conference was reached. The results of the discussion were used to revise the manuscript into its final form.
CONCLUSIONS
Consensus was reached on 5 conclusions and 2 recommendations concerning the use of testing for dysfibrinogens in the assessment of thrombotic risk in individual patients. Detailed discussion of the rationale for each of these recommendations is found in the text of this article. Compared with the other, more common hereditary thrombophilias, dysfibrinogenemia encompasses a diverse group of defects with varied clinical expressions. Congenital dysfibrinogenemia is a relatively rare cause of thrombophilia. Therefore, routine testing for this disorder is not recommended as part of the laboratory evaluation of a thrombophilic patient. This is an evolving area of research, and further clinical studies may change these recommendations in the future.
Topics: Afibrinogenemia; Blood Coagulation Tests; Evidence-Based Medicine; Fibrinogens, Abnormal; Humans; Practice Guidelines as Topic; Risk Assessment; Risk Factors; Thrombophilia; Thrombosis
PubMed: 12421146
DOI: 10.5858/2002-126-1387-DAT -
Current Opinion in Hematology Sep 1997Fibrinogen abnormalities can be classified as congenital or acquired. Each class manifests quantitative or qualitative alterations; the latter are known as... (Review)
Review
Fibrinogen abnormalities can be classified as congenital or acquired. Each class manifests quantitative or qualitative alterations; the latter are known as dysfibrinogenemias. In dysfibrinogenemias, structural defects cause alterations in the conversion of fibrinogen to fibrin. Approximately 300 abnormal fibrinogens have been reported, and about 83 structural defects have been identified. The most common structural defect involve the fibrinopeptides and their cleavage sites, and the second most common involves the gamma-chain polymerization region. Approximately half of the mutants are clinically silent, whereas hemorrhage and thrombosis occur in almost equal numbers of cases. Study of the abnormal fibrinogens has provided insight into fibrinogen structure and fibrin formation and dissolution. Some of the structural abnormalities exhibit defective assembly and activation of components of the fibrinolytic system on the abnormal fibrin, resulting in impaired dissolution of fibrin, clinically associated with thrombosis.
Topics: Afibrinogenemia; Fibrinogen; Fibrinogens, Abnormal; Humans; Models, Molecular; Thrombosis; Wound Healing
PubMed: 9288470
DOI: 10.1097/00062752-199704050-00010 -
Clinical Advances in Hematology &... Sep 2018
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Polskie Archiwum Medycyny Wewnetrznej Sep 2011Acquired qualitative abnormalities of fibrinogen molecules, termed acquired dysfibrinogenemia, have been demonstrated in several disease states mostly related to... (Review)
Review
Acquired qualitative abnormalities of fibrinogen molecules, termed acquired dysfibrinogenemia, have been demonstrated in several disease states mostly related to prothrombotic tendency, including multiple myeloma and liver disease. Fibrin is abundant in atherosclerotic plaques. Altered plasma fibrin properties, reflected usually by reduced clot permeability and impaired fibrinolysis, have been reported in patients with acute or prior myocardial infarction, ischemic stroke, and peripheral artery disease. Moreover, prothrombotic clot phenotype has been observed in patients with previous no-reflow phenomenon and stent thrombosis. Growing evidence indicates that acquired dysfibrinogenemia contributes to the progression of atherosclerotic vascular disease and the occurrence of its thrombotic manifestations. The review summarizes current knowledge on the links between fibrin clot phenotype and atherosclerotic vascular disease and describes a wide spectrum of cardiovascular risk factors as modifiers of fibrin network characteristics.
Topics: Atherosclerosis; Fibrin; Fibrinogens, Abnormal; Humans; Plaque, Atherosclerotic; Risk Factors
PubMed: 21952526
DOI: No ID Found -
Journal of Thrombosis and Haemostasis :... Jun 2015Congenital dysfibrinogenemia is a qualitative congenital fibrinogen disorder characterized by normal antigen levels of a dysfunctional fibrinogen. The diagnosis is... (Review)
Review
Congenital dysfibrinogenemia is a qualitative congenital fibrinogen disorder characterized by normal antigen levels of a dysfunctional fibrinogen. The diagnosis is usually based on discrepancies between fibrinogen activity and antigen levels, but could require more specialized techniques for the assessment of fibrinogen function, owing to some limitations in routine assays. Molecular abnormalities, which are frequently heterozygous missense mutations localized in exon 2 of FGA and exon 8 of FGG, lead to defects in one or more phases of fibrinogen to fibrin conversion, fibrin network formation, and other important functions of fibrinogen. The clinical phenotype is highly heterogeneous, from no manifestations to bleeding and/or thrombotic events. Asymptomatic propositi and relatives with the predisposing genotype are at risk of developing adverse outcomes during the natural course of the disease. Correlations between genotype and phenotype have not yet been clearly established, with the exception of some abnormal fibrinogens that severely increase the risk of thrombosis. Functional analysis of polymerization and fibrinolysis, structural studies of the fibrin network and the viscoelastic properties of fibrin clot could help to predict the phenotype of congenital dysfibrinogenemia, but have not yet been evaluated in detail. The management is essentially based on personal and family history; however, even individuals who are still asymptomatic and without a family history should be carefully assessed and monitored. Particular situations, such as pregnancy, delivery, and surgery, require a multidisciplinary approach.
Topics: Afibrinogenemia; Animals; Blood Coagulation; Blood Coagulation Tests; DNA Mutational Analysis; Female; Fibrinogens, Abnormal; Genetic Predisposition to Disease; Humans; Male; Molecular Diagnostic Techniques; Mutation; Phenotype; Predictive Value of Tests; Pregnancy; Pregnancy Complications, Hematologic; Prognosis; Risk Factors; Thrombosis
PubMed: 25816717
DOI: 10.1111/jth.12916