Phenotype and genotype analyses of two pedigrees with inherited fibrinogen deficiency / 中华血液学杂志

Objective: To analyze the phenotype and genotype of two pedigrees with inherited fibrinogen (Fg) deficiency caused by two heterozygous mutations. We also preliminarily probed the molecular pathogenesis. Methods: The prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and plasma fibrinogen activity (Fg∶C) of all family members (nine people across three generations and three people across two generations) were measured by the clotting method. Fibrinogen antigen (Fg:Ag) was measured by immunoturbidimetry. Direct DNA sequencing was performed to analyze all exons, flanking sequences, and mutated sites of FGA, FGB, and FGG for all members. Thrombin-catalyzed fibrinogen polymerization was performed. ClustalX 2.1 software was used to analyze the conservatism of the mutated sites. MutationTaster, PolyPhen-2, PROVEAN, SIFT, and LRT online bioinformatics software were applied to predict pathogenicity. Swiss PDB Viewer 4.0.1 was used to analyze the changes in protein spatial structure and molecular forces before and after mutation. Results: The Fg∶C of two probands decreased (1.28 g/L and 0.98 g/L, respectively). The Fg∶Ag of proband 1 was in the normal range of 2.20 g/L, while it was decreased to 1.01 g/L in proband 2. Through genetic analysis, we identified a heterozygous missense mutation (c.293C>A; p.BβAla98Asp) in exon 2 of proband 1 and a heterozygous nonsense mutation (c.1418C>G; p.BβSer473*) in exon 8 of proband 2. The conservatism analysis revealed that Ala98 and Ser473 presented different conservative states among homologous species. Online bioinformatics software predicted that p.BβAla98Asp and p.BβSer473* were pathogenic. Protein models demonstrated that the p.BβAla98Asp mutation influenced hydrogen bonds between amino acids, and the p.BβSer473* mutation resulted in protein truncation. Conclusion: The dysfibrinogenemia of proband 1 and the hypofibrinogenemia of proband 2 appeared to be related to the p.BβAla98Asp heterozygous missense mutation and the p.BβSer473* heterozygous nonsense mutation, respectively. This is the first ever report of these mutations.

A Family with Congenital Dysfibrinogenemia and Blood Transfusion / 中国实验血液学杂志

OBJECTIVE@#To investigate a family with congenital dysfibrinogenemia, and analyze the risk of hemorrhage and thrombosis and blood transfusion strategies.@*METHODS@#Prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) of the proband and her family members were detected by automatic coagulometer, fibrinogen (Fg) activity and antigen were detected by Clauss method and PT algorithm respectively. Meanwhile, thromboelastometry was analyzed for proband and her family members. Then, peripheral blood samples of the proband and her family members were collected, and all exons of FGA, FGB and FGG and their flanks were amplified by PCR and sequenced to search for gene mutations.@*RESULTS@#The proband had normal APTT and PT, slightly prolonged TT, reduced level of Fg activity (Clauss method). The Fg of the proband's aunt, son and daughter all decreased to varying degrees. The results of thromboelastogram indicated that Fg function of the proband and her family members (except her son) was basically normal. Gene analysis showed that there were 6233 G/A (p.AαArg35His) heterozygous mutations in exon 2 of FGA gene in the proband, her children and aunt. In addition, 2 polymorphic loci were found in the family, they were FGA gene g.9308A/G (p.AαThr331Ala) and FGB gene g.12628G/A (p.BβArg478Iys) polymorphism, respectively. The proband was injected with 10 units of cryoprecipitate 2 hours before delivery to prevent bleeding, and no obvious bleeding occurred during and after delivery.@*CONCLUSION@#Heterozygous mutation of 6233G/A (p.AαArg35His) of FGA gene is the biogenetic basis of the disease in this family with congenital dysfibrinogenemia.

Genetic analysis of a Chinese pedigree affected with Congenital dysfibrinogenemia due to variant of FGG gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the coagulation deficit and genetic basis for a Chinese pedigree affected with Congenital dysfibrinogenemia (CD).@*METHODS@#Peripheral venous blood samples of the proband and her family members (including 4 individuals from three generations) were subjected to routine blood test and assays of liver and kidney functions and viral hepatitis to exclude related diseases. Clauss method and DFg-PT method were used to determine the fibrinogen activity (Fg:C), and an immunoturbidimetric assay was used to determine the level of fibrinogen antigen (Fg:Ag). All of the exons (22 in total) and their flanking sequences of the FGA, FGB and FGG genes were amplified by PCR and directly sequenced. Variants in the coding regions of the three genes and transcriptional splicing sites were screened by using Mutation SurveyorTM software.@*RESULTS@#The Clauss method showed that Fg:C was significantly reduced in the proband and her father, whilst her mother and son were normal. With the DFg-PT method, the proband, her parents and son were all within the normal range. The Fg:C/Fg:Ag ratio of the proband and her father was lower than 0.7, whilst her mother and son were above 0.7. No significant change in the prothrombin time, activated partial thromboplastin clotting time and thrombin time was noted. Two genetic variants were detected, which included a homozygous missense variant in the FGA gene [c.991A>G (p.Thr331Ala)], which was predicted to be benign, and a heterozygous missense variant of the γ chain of the FGG gene [c.1211C>G (p.Ser404Phe)], which is located in a conserved region and unreported in the CLINVAR/HGMD/EXAC/1000G databases and literature.@*CONCLUSION@#This pedigree has conformed to the autosomal dominant inheritance of CD. The c.1211C>T (p.Ser404Phe) missense variant of the γ chain of the FGG gene probably underlay the pathogenesis of CD in this pedigree. The variant was unreported previously and named as "Fibrinogen Harbin II Ser404Phe".

Genetic analysis of two Chinese pedigrees affected with Hereditary hypofibrinemia due to missense variants / 中华医学遗传学杂志

OBJECTIVE@#To retrospectively analyze the clinical phenotypes and genetic variants in two Chinese pedigrees affected with Hereditary hypofibrinemia (IFD) and explore their molecular pathogenesis.@*METHODS@#Two probands and their pedigree members were admitted to the First Affiliated Hospital of Wenzhou Medical University on March 30, 2021 and May 27, 2021, respectively. Clinical phenotypes of the probands were collected, and blood clotting indexes of the probands and their pedigree members were determined. Variants of the FGA, FGB and FGG genes were analyzed by Sanger sequencing, and candidate variants were verified by sequence comparison. Bioinformatic software was used to analyze the conservation of the amino acids and pathogenicity of the proteins. Alteration in protein structure and intermolecular force before and after the variant was analyzed by simulating the protein model.@*RESULTS@#Proband 1, a 18-year-old male, had significantly low plasma fibrinogen activity (Fg:C) and plasma fibrinogen antigen (Fg:Ag), respectively at 0.80 g/L and 1.00 g/L. Proband 2, a 43-year-old male, had slightly low Fg:C and Fg:Ag at 1.35 g/L and 1.30 g/L, respectively. The Fg:C and Fg:Ag of proband 1's father, proband 2's father and son were also below the normal level. Genetic testing showed that proband 1 had harbored a heterozygous missense variant of c.688T>G (p.Phe230Val) in exon 7 of the FGG gene, which was inherited from his father. Proband 2, his father and son all had harbored a heterozygous variant of c.2516A>C (p.Asn839Thr) in exon 6 of the FGA gene. Homology analysis showed that the Phe230 and Asn839 residues were highly conserved among homologous species. Bioinformatic analysis predicted that both p.Phe230Val and p.Asn839Thr were pathogenic variants.@*CONCLUSION@#Analysis of protein simulation model showed that the p.Asn839Thr variant has changed the hydrogen bo`nd between the amino acids, thus affecting the stability of the protein structure. The heterozygous missense variants of p.Phe230Val and p.Asn839Thr probably underlay the IFD in the two pedigrees.

Research Advance of the Mechanisms, Clinical Characteristics and Treatment Strategy of Coagulation Dysfunction in Hemophagocytic Lymphohistiocytosis --Review / 中国实验血液学杂志

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease caused by uncontrolled proliferation of activated macrophage, and secreting high amounts of inflammatory cytokines which lead to multi-organ dysfunction syndrome. HLH patients often show different clinical characteristics during the disease was progressed, in which coagulopathy were the most common, including thrombocytopenia and hypofibrinogenemia, those are the major cause of death in patients, and the clinicians should increase awareness of the mechanisms, clinical characteristics, prognosis and treatment. In this review, the above problems are briefly summarized, to deepen understanding of the HLH related coagulation dysfunctions, and early identification and treatment to reduce mortality, so as to provide more opportunities for HLH patients to recieve subsequent treatment.

Aetiology of pancytopenia: Experience of a South African tertiary academic centre

Background: Pancytopenia is a manifestation of numerous disease entities. The causes of pancytopenia differ with geographic region, socio-economic factors and HIV prevalence. Awareness of the common causes of pancytopenia may aid timely diagnosis. Objective: This study aimed to determine the aetiology of pancytopenia in a South African population.Methods: A retrospective observational study of adult patients presenting with pancytopenia at Tygerberg Academic Hospital, South Africa, from January 2016 to December 2017 was performed. Data on pancytopenia cases were obtained from the laboratory information system and utilised to determine the causes of pancytopenia. Results: A total of 673 cases of pancytopenia were identified. The most common causes of pancytopenia were chemoradiation therapy (25%), sepsis (18%), haematological malignancy (9%), advanced HIV (7%), and megaloblastic anaemia (6%). The diagnostic yield of bone marrow examinations (BME) was 57% (n = 52/91). The aetiology of pancytopenia differed according to age, with malignancy being a more common cause of pancytopenia among the elderly. Conclusion: Several easily recognisable and treatable conditions can manifest as pancytopenia. Prompt management of such conditions, notably sepsis and megaloblastic anaemia, can result in the resolution of the cytopenias and negate the need for a BME. However, haematological malignancy and unexplained pancytopenia strongly rely on a BME to establish a diagnosis. Pancytopenia investigations, when guided by appropriate clinic-laboratory findings, can promptly identify the underlying aetiology, while also identifying cases where an expedited BME is required. This is valuable in resource-conscious medicine

Uso de concentrados de fibrinógeno para el tratamiento de la hipofibrinogenemia adquirida / Use of Fibrinogen Concentrates for the Treatment of Acquired Hypofibrinogenemia

Resumen Introducción: Un adecuado manejo del sangrado debe incluir la correcta valoración y eventual reposición de fibrinógeno. Las fuentes tradicionales de este elemento hemostático incluyen el plasma fresco congelado y los crioprecipitados. Los concentrados liofilizados de fibrinógeno humano (CFH) son una alternativa terapéutica novedosa en el mercado chileno. Objetivo: Este estudio describe el curso clínico de los primeros pacientes en nuestra institución requirentes de CFH, dentro de un algoritmo de reposición hemostática por metas. Materiales y Método: Serie de pacientes con hipofibrinogenemia secundaria a sangrado perioperatorio severo, en los que se utilizó CFH como método de reposición de fibrinógeno. Se utilizó tromboelastometría para definir dosis. Se registraron variables demográficas, operatorias, complicaciones y seguimiento hasta los 3 meses. Resultados: Se utilizaron CFH en 18 pacientes. La mediana de edad fue 40,7 (56,5-63) años y dos tercios de los pacientes fueron de sexo masculino. Fallecieron 5 pacientes de la serie. Todos los pacientes requirieron manejo posoperatorio en una unidad de cuidados intensivos. Ocho pacientes fueron sometidos a cirugía cardiaca. El uso de hemocomponentes y concentrados liofilizados fue heterogéneo, pero en todos los casos su uso fue determinado por tromboelastometría. Ningún paciente fue reintervenido a causa de sangrado posoperatorio. Conclusión: El uso de concentrados de fibrinógeno humano dentro de un algoritmo de manejo de sangrado guiado por tromboelastometría, es un recurso hemostático factible en la realidad nacional. El impacto clínico de esta intervención requiere una subsiguiente evaluación basada en la evidencia.

Introduction: An adequate bleeding management should include a proper assessment of fibrinogen values and consequent replacement. Traditional sources for this hemostatic element include fresh frozen plasma and cryoprecipitates. Lyophilized human fibrinogen concentrates are a novel therapeutic alternative for the chilean market. Aim: This study aims to describe the clinical course of the first patients in our institution receiving fibrinogen concentrates, included in a goal directed hemostatic management algorithm. Materials and Method: Case series of patients with hypofibrinogenemia secondary to severe perioperative bleeding, in which fibrinogen concentrate was used for fibrinogen replacement. Thromboelastometry was used to define dose regimens. Demographic and surgical variables, complications and follow-up up to 3 months were registered. Results: Fibrinogen concentrate was used in 18 patients. Median age was 40.7 (56.5-63) years, and two thirds of the patients were male. Five patients died. All of the cases required postoperative intensive care. Eight patients underwent cardiac surgery. There was a heterogenic use of blood derived products and lyophilized concentrates, but in all cases its use was guided by thromboelastometry. No patients needed a secondary exploration due to bleeding. Conclusion: The use of human fibrinogen concentrate included in a bleeding management algorithm is a feasible hemostatic resource in the chilean current situation. The clinical impact of this intervention requires further evidence-based evaluation.

Congenital Fibrinogen Deficiency Caused by Novel FGG Gene Mutation / 中国实验血液学杂志

OBJECTIVE@#To detect and analyze coagulation related indexes and genotypes of a patient with congenital fibrinogen deficiency and his family members, and to investigate the possible molecular pathogenesis.@*METHODS@#Four peripheral blood samples (proband and 3 family members) were collected and the prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fg), D-Dimer and eight coagulation factor indicators were detected. All exons and flanking sequences of the FGA, FGB, and FGG genes encoding the three peptide chains of fibrinogen were sequenced and analyzed by bioinformatics.@*RESULTS@#Among the eight coagulation factors of the proband and the elder sister, F Ⅴ and F Ⅷ were slightly higher, TT was significantly prolonged, and Fg was significantly reduced. Sequencing results showed that c.901C>T heterozygous mutation existed in the FGG gene. Bioinformatics analysis showed that the mutation changed the original protein structure and reduced the number of hydrogen bonds.@*CONCLUSION@#The fibrinogen gamma chain c.901C>T heterozygous mutation is the main cause of congenital fibrinogen deficiency in this family. This mutation is reported for the first time at home and abroad.

Early administration of fibrinogen concentrate in patients with polytrauma with thromboelastometry suggestive of hypofibrinogenemia: A randomized feasibility trial

OBJECTIVE: To evaluate the clinical effects of early administration of fibrinogen concentrate in patients with severe trauma and hypofibrinogenemia. METHODS: We conducted an open randomized feasibility trial between December 2015 and January 2017 in patients with severe trauma admitted to the emergency department of a large trauma center. Patients presented with hypotension, tachycardia, and FIBTEM findings suggestive of hypofibrinogenemia. The intervention group received fibrinogen concentrate (50 mg/kg), and the control group did not receive early fibrinogen replacement. The primary outcome was feasibility assessed as the proportion of patients receiving the allocated treatment within 60 min after randomization. The secondary outcomes were transfusion requirements and other exploratory outcomes. Randomization was performed using sequentially numbered and sealed opaque envelopes. ClinicalTrials.gov: NCT02864875. RESULTS: Thirty-two patients were randomized (16 in each group). All patients received the allocated treatment within 60 min after randomization (100%, 95% confidence interval, 86.7%-100%). The median length of intensive care unit stay was shorter in the intervention group (8 days, interquartile range [IQR] 5.75-10.0 vs. 11 days, IQR 8.5-16.0; p=0.02). There was no difference between the groups in other clinical outcomes. No adverse effects related to treatment were recorded in either group. CONCLUSION: Early fibrinogen replacement with fibrinogen concentrate was feasible. Larger trials are required to properly evaluate clinical outcomes.

A case of inherited afibrinogenemia caused by an IVS7-12A>G splice mutation of FGG gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with inherited afibrinogenemia.@*METHODS@#For the proband and his family members, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), Fibrin(ogen) degradation products (FDPs), D-dimer (D-D), plasminogen activity (PLG:A) and the TT mixed experiment with protamine sulfate were determined with a STAGO-R automatic coagulation analyzer. The activity and antigen of fibrinogen (Fg) in plasma were measured with the Clauss method and immunonephelometry method, respectively. All exons and flanking regions of the fibrinogen genes (FGA, FGB and FGG) were amplified by PCR and directly sequenced. Human Splicing Finder software was used to predict and score the change of splicing site caused by the mutation.@*RESULTS@#The proband showed normal FDPs and D-D but significantly prolonged TT, PT and APTT. The activity and antigen of fibrinogen in plasma were significantly decreased (G (g.4147A>G) mutations of the FGG gene, for which his parents and young sister were heterozygous. As predicted by Human Splicing Finder and Mutation Taster software, the variant may generate a new splicing site which can extend the sequence of exon 7 by 11 bp, with alteration of the coding sequence. PROVEAN suggested the variant to be deleterious.@*CONCLUSION@#The afibrinogenemia of the proband may be attributed to the FGG IVS7-12A>G variant, which was unreported previously.

Analysis of a pedigree affected with congenital dysfibrinogenemia due to a novel Gly31Glu mutation of FGA gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the phenotype and genotype of a pedigree affected with congenital dysfibrinogenemia.@*METHODS@#Liver and kidney functions of the proband and her relatives were determined. Coagulation tests including prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time(TT), fibrin(ogen) degradation products (FDPs), D-dimer(D-D) and the calibration experiment of protamine sulfate of against plasma TT were detected in the proband and her predigree members. The activity and antigen of fibrinogen (Fg) in plasma were measured by Clauss method and immunonephelometry method, respectively. All of the exons and exons-intron boundaries of the three fibrinogen genes (FGA, FGB and FGG) were subjected to PCR amplification and Sanger sequencing. Potential influence of the suspected mutations were analyzed with bioinformatics software including PolyPhen-2, SIFT and Mutation Taster.@*RESULTS@#The proband had normal PT, APTT, FDPs, D-D and prolonged TT (31.8 s). The activity of fibrinogen (Fg) in plasma was significantly decreased but the antigen was normal. Genetic analysis revealed a heterozygous c.92G>A (p.Gly31Glu) mutation in exon 2 of the FGA gene. Family studies revealed that the mother carried the same mutation. Bioinformatic analysis suggested that the mutation may affect the function of Fg Protein.@*CONCLUSION@#The dysfibrinogenemia was probably caused by the novel Gly31Glu mutation of the FGA gene.

Perioperative management of pregnant women combined with congenital fibrinogen deficiency: four cases report and literature review / 北京大学学报(医学版)

Congenital fibrinogen deficiency is an autosomal recessive or dominant disorder in which quantitative (afibrinogenaemia or hypofibrinogenaemia) or qualitative (dysfibrinogenaemia) defects in the fibrinogen Aa, Bb or c protein chains that lead to reduced functional fibrinogen. We now report the perioperative management of 4 pregnant women suffering from hypofibrinogenaemia scheduled for elective caesarean section from December 2012 to October 2016 in Peking University First Hospital and review this disease with reference to classification, symptom, replacement therapy, and selection of the modes of pregnancy termination and anesthesia. The four patients were all asymptomatic, whereas there existed recurrent pregnancy loss (case 3), family history (case 2), and offspring heredity (cases 3 and 4). Routine clotting studies revealed low fibrinogen levels and prolonged thrombin time (TT) during pregnancy and on admission. However, the platelet (PLT) count, prothrombin time (PT) and activated partial thromboplastin time (APTT) were normal. All the patients were administered fibrinogen concentrate perioperatively, and underwent uncomplicated combined spinal-epidural anesthesia and uneventful surgical procedure without postpartum hemorrhage. The replacement therapy of fibrinogen or fresh frozen plasma administration was essential to avoid anesthesia and obstetric complications. Regional blockade could safely be offered in the caesarean section, providing that their coagulation defect was corrected by availability of therapeutic products and adequate response to treatment. In addition, the point-of-care rotational thrombelastometry (ROTEM) or thrombelastogram (TEG) could play an important role in an optimal perioperative management for such patients. Management plans must be tailored to each individual, taking into consideration their bleeding risk as well as potential maternal and neonatal complications.

Mutation analysis of a FGG gene causing hereditary abnormal fibrinogen / 中华医学遗传学杂志

OBJECTIVE@#To study the clinical phenotype and gene mutation analysis of a hereditary abnormal fibrinogenemia family and explore its molecular pathogenesis.@*METHODS@#The STA-R automatic hemagglutination analyzer to detect the proband and its family members (3 generations of 5 people) of prothrombin time(PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen activity (Fg: C), D-dimer (D-D), fibrinogen and fibrin degradation products (FDPs), plasminogen activity (PLG: A); The plasma levels of Fg: C and fibrinogen (Fg: Ag) were measured by Clauss method and immunoturbidimetry respectively. All exons and flanking sequences of FGA, FGB and FGG genes of fibrinogen were amplified by PCR, and the PCR products were purified and sequenced for gene analysis. The model was analyzed by Swiss software.@*RESULTS@#The PT and APTT of the proband, her mother and sister were slightly prolonged, TT was significantly extend, Fg: C decreased significantly, Fg: Ag, PLG: A, D-D and FDPs are within the normal range; Her brother and daughter of the results are normal. Genetic analysis showed that g.7476 G>A heterozygous missense mutation in exon 8 of FGG gene resulted in mutations in arginine at position 275 of fibrinogen gamma D domain to histidine (Arg275His). Her mother and sister have the same Arg275His heterozygous mutation, brother and daughter for the normal wild type.@*CONCLUSION@#The heterozygous missense mutation of FGG gene Arg275His in patients with hereditary dysfibrinogenemia is associated with a decrease in plasma fibrinogen activity.

Analysis of a pedigree affected with congenital hypofibrinogenemia due to heterozygous Ser313Ile mutation of fibrinogen γ chain gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic basis for a Chinese pedigree affected with congenital hypofibrinogenamia.</p><p><b>METHODS</b>Peripheral blood samples were collected from 9 members from the pedigree. Routine coagulation tests including activated partial thromboplastin time (APTT), thrombin time (TT), the prothrombin time (PT) were carried out. The activity of fibrinogen (Fg: C) was measured using Clauss method, and fibrinogen antigen (Fg: Ag) was measured with immunoturbidimetry. All exons and exon-intron boundaries of the fibrinogen Aα, Bβ and γ chain genes were amplified using PCR, which was followed by direct sequencing. Suspected mutation was confirmed by reverse sequencing. The mutant fibrinogen was analyzed with Swiss-PdbViewer.</p><p><b>RESULTS</b>The proband showed prolonged APTT, PT and TT. Her functional fibrinogen (Fg: C) and antigen fibrinogen (Fg: Ag) levels were reduced to 0.69 g/L and 0.72 g/L, respectively. Her mother and grandmother also had a low levels of fibrinogen, which were 0.99 g/L and 0.83 g/L for Fg: C, 1.02 g/L and 0.87 g/L for Fg: Ag, respectively. The results of other members from the pedigree were all within the normal range. Genetic analysis reveled a heterozygous G>T mutation at nucleotide 7590 in exon 8 of γ gene in the proband, which was predicted to be a novel Ser313Ile mutation. The mutation was also found in her mother and grandmother. Model analysis showed that the Ser313Ile mutation disturbed the hydrogen bonds between Ser313, Asn319 and Asp320. Moreover, the mutation also altered the mutual electrostatic force and affected the folding and instability of the mutant fibrinogen.</p><p><b>CONCLUSION</b>The heterozygous Ser313Ile mutation probably underlies the hypofibrinogenemia in this pedigree.</p>

Analysis of a family with congenital dysfibrinogenemia caused by an Arg275His mutation in the gamma chain of fibrinogen / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the clinical phenotype of a family affected with congenital dysfibrinogenemia and potential mutations underlying the disease.</p><p><b>METHODS</b>Coagulation testing and hepatorenal function testing were conducted on 18 individuals from three generations. Plasma fibrinogen was extracted and analyzed with SDS-PAGE electrophoresis. All of the exons and flanking sequences of fibrinogen FGA, FGB, FGG genes were analyzed by PCR, and the products were subjected to Sanger sequencing.</p><p><b>RESULTS</b>Hepatorenal function, prothrombin time and activated partial thromboplastin time of the proband were all normal. However, his thrombin time was significantly prolonged. Fibrinogen activity was decreased, while the concentration of antigen was in the normal range. The results of his mother, brother, and nephew were similar. DNA sequencing has confirmed that the proband, his mother, brother, and nephew have all carried a g.5877G>A mutation in the exon 8 of the FGG gene, which resulted in replacement of arginine (Arg) by histidine (His) at position 275.</p><p><b>CONCLUSION</b>The Arg275His mutation of the fibrinogen gamma chain probably underlies the pathogenesis of congenital dysfibrinogenemia in this family.</p>

Congenital hypofibrinogenemia associated with a novel mutation in FGG gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the genetic mutation underlying congenital hypofibrinogenamia in a Chinese pedigree.</p><p><b>METHODS</b>Standard coagulation tests including the prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), plasminogen activity (PLG:A), D-Dimer (DD) and fibrin degradation products (FDP) were tested with fresh plasma using a STA-R analyzer. The activity of fibrinogen (Fg:C) and fibrinogen antigen (Fg:Ag) were measured respectively with the Clauss method and immunoturbidimetry. All exons and exon-intron boundaries of the fibrinogen Aα-, Bβ-, and γ-chain genes (FGA, FGB and FGG) were amplified by PCR followed by direct sequencing. Suspected mutation was confirmed by reverse sequencing and analyzed with a Swiss-PdbViewer.</p><p><b>RESULTS</b>The PT level in the proband was normal, while the APTT and TT were slightly prolonged. The functional and antigen fibrinogen levels were both significantly reduced (0.91 g/L and 0.95 g/L, respectively). Similar abnormalities were also found in her father, elder sister, son and niece. The coagulant parameters of her mother were all within the normal range. Genetic analysis has reveled a heterozygous A>C change at nucleotide 5864 in exon 7 of γ gene in the proband, predicting a novel Lys232Thr mutation. The proband's father, elder sister, son and niece were all carriers of the same mutation. Protein model analysis indicated that the Lys232Thr mutation did not disrupt the native network of hydrogen bonds, but has changed the mutual electrostatic forces, resulting in increased instability of the protein.</p><p><b>CONCLUSION</b>The heterozygous Lys232Thr mutation identified in the FGG gene probably underlies the hypofibrinogenemia in this pedigree.</p>

Analysis of molecular pathogenesis and clinical phenotypes in 10 probands with inherited fibrinogen deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular pathogenesis and clinical phenotypes in 10 probands with inherited fibrinogen (Fg) deficiency.</p><p><b>METHODS</b>The diagnosis of hereditary Fg deficiency was validated by prothrombin time (PT), thrombin time (TT), Fg activity (Fg:C) and Fg antigen (Fg:Ag) in plasma. All of the exons and their flanking sequences of the Fg gene were analyzed by direct sequencing. Detected mutations were confirmed by reverse sequencing.</p><p><b>RESULTS</b>The ranges of Fg:C and Fg:Ag in the 10 probands were 0.52-0.91 g/L and 0.62-2.98 g/L, respectively. Five of the probands had type I disorders, and 5 had type II disorders. Seven point mutations were identified, among which 6 have located in the D region. γThr277Arg, γAsp316His, γTrp208Leu and Lys232Thr were novel mutations, and αArg19Ser was first reported in Chinese. Four probands had the same mutation site (γArg275). As to the clinical manifestation, probands with type I disorders were asymptomatic or with mild or medium symptoms, while those belonged to type II disorders had moderate or serious symptoms. Two probands have carried an Arg275Cys mutation but had different clinical manifestations.</p><p><b>CONCLUSION</b>Mutations of the Fg gene seem to aggregate to the D region of FGG in our region, and Arg275 is a common mutation. However, no correlation has been found between the mutation site and clinical manifestations.</p>

Massive hemoperitoneum due to a ruptured corpus luteum cyst in a patient with congenital hypofibrinogenemia

Congenital afibrinogenemia/hypofibrinogenemia is a rare inherited hematologic disorder in which a patient lacks or has insufficient level of fibrinogen, the blood coagulation factor I. The incidence of this uncommon disease is 1 to 2 per 1 million individuals. Hence, massive hemoperitoneum caused by ovulation in a woman with congenital afibrogenemia is also a very rare clinical condition. Massive hemoperitoneum usually presents as acute abdominal pain with potential findings of peritonitis including abdominal distention, hypotension and tachycardia with critical consequences. We performed emergent endoscopic surgery for hemoperitoneum caused by a ruptured corpus luteum cyst in a patient with congenital hypofibrinogenemia. To the best of our knowledge, this was the first case report of such treatment in Korea.

Clinical and genetic analysis of 8 Chinese pedigrees with inherited dysfibrinogenemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze clinical manifestation and genetic mutations in 8 Chinese pedigrees featuring hereditary dysfibrinogenemia.</p><p><b>METHODS</b>Prothrombin time(PT), activated partial thromboplastin time(APTT), thrombin time(TT), calibration of plasma protamine sulfate against TT, fibrinogen (Fg) activity, coagulation factors II, V, VII, VIII, IX, X, XI and XII of all probands and their family members were detected with an automatic blood coagulation analyzer; D-dimer(D-D) and fibrin(ogen) degradation products(FDPs) were also dtected by automatic blood coagulation analyzer, Fg antigen were detected with an immunoturbidimetry method. Exons of fibrinogen genes FGA, FGB and FGG and flanking sequences were amplified by polymerase chain reaction(PCR) and sequenced.</p><p><b>RESULTS</b>All of the probands showed normal levels of FDPs, D-dimer(D-D) and activity of coagulation factor II,V,VII, VIII, IX,X,XI, XII. Plasma PT and APTT were normal or slightly prolonged. Prolonged TT was found in all of the probands, whilst TT was not significantly shortened by protamine sulfate. Fg antigen was within the normal range, but Fg activity was significantly decreased. The Fg antigen/activity ratio was greater than 2. One proband has carried a heterozygous variant of the FGA gene g.1233G>A(p.A α Arg35His). Four have carried a heterozygous mutation of the FGB gene g.9692A>G(p.Bβ Asn190Ser). The remaining 3 had heterozygous substitution of FGG gene g.10819G>A(p.γ Arg301His). In addition, 2 polymorphisms (p.A α Thr331Ala) and p.B β Arg478Lys) were identified in FGA and FGB genes.</p><p><b>CONCLUSION</b>p.A α Arg35His, p.B β Asn190Ser and p. γ Arg301His are responsible for the inherited dysfibrinogenemia in the 8 Chinese pedigrees. p.B β Asn190Ser is firstly reported in China. p.B β Asn190Ser and p. γ Arg301His may be mutation hot spot in the Chinese population.</p>

Research progress on hereditary fibrinogen abnormalities / 中国实验血液学杂志

As the most abundant component of coagulation system, fibrinogen not only takes part in clotting, but also works as one of acute phase proteins, which participates in many physiological and pathophysiological processes. Studies of fibrinogen abnormalities contribute to understand the molecular basis of disorders of fibrinogen protein function and metabolism, caused mainly by gene mutation, commonly associated with bleeding, thrombophilia, or both. Diseases affecting fibrinogen could be classified to the acquired or inherited disease. In this review, the research progress on the molecular basis, possible action mechanism of the hereditary fibrinogen abnormalities and its clinical research are summarized.