OBJECTIVETo analyze the phenotype and genotype of a family with inherited dysfibrinogenemia.

METHODSAssays of coagulation, including activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT), were carried out with Stago Compact in the proband and his family members. The activity and antigen of fibrinogen in plasma were determined by Clauss and immunoturbidimetry, respectively. Fibrinogen and its constituent were analyzed by Western blot with nonreducing 4%-20% SDS-polyacrylamide gel electrophoresis (PAGE). All exons and exon-intron boundaries of fibringen genes FGA, FGB and FGG were analyzed by PCR and then direct sequencing.

RESULTSThe proband had normal APTT and PT, but prolonged TT. The activity of fibrinogen in plasma was decreased while its antigen level was normal. These abnormalities were also found in his mother and a sister. Genetic analysis revealed heterozygous G1233A in the exon 2 of FGA originating from his mother, which resulted in Arg16His missense mutation.

CONCLUSIONInherited dysfibrinogenemia was caused by Arg16His mutation in exon 2 of FGA, and this is the first case reported in a Chinese family.

Fibrinogen ; genetics ; Genotype ; Humans ; Mutation ; Pedigree ; Phenotype

OBJECTIVETo analyze clinical manifestation and genetic mutations in 8 Chinese pedigrees featuring hereditary dysfibrinogenemia.

METHODSProthrombin 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.

RESULTSAll 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.

CONCLUSIONp.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.

Afibrinogenemia ; blood ; genetics ; Fibrin Fibrinogen Degradation Products ; analysis ; Fibrinogen ; analysis ; genetics ; Humans ; Pedigree

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.
Humans ; Afibrinogenemia/genetics* ; Codon, Nonsense ; Pedigree ; Phenotype ; Fibrinogen/genetics* ; Genotype

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.
Afibrinogenemia/genetics* ; Aged ; Fibrinogen/genetics* ; Heterozygote ; Humans ; Mutation ; Pedigree

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.
Afibrinogenemia ; genetics ; DNA Mutational Analysis ; Female ; Fibrinogen ; genetics ; Fibrinogens, Abnormal ; genetics ; Humans ; Male ; Mutation ; Pedigree

OBJECTIVETo construct the siRNA plasmid for mfgl2 gene, which has been reported to be involved in a variety of disease developments including fulminant viral hepatitis, acute rejection of allo/zero transplantation and fetal loss syndrome, and to investigate its inhibitory effects on mfgl2 expression in vitro.

METHODSA plasmid p-mfgl2shRNA complimentary to the sequence responsible for the functional domain of mouse fgl2 (mfgl2) was constructed. The pcDNA3.1 mfgl2 expression construct was able to show a satisfactory fgl2 protein expression. The plasmid expression pEGFP and a construct expressing irrelevant shRNA with a random combination of the p-mfgl2shRNA sequence were used as controls. A pEGFP-mfgl2 expressing mfgl2-EGFP fusion protein was also constructed for screening of the effect of p-mfgl2shRNA on the mfgl2 expression.

RESULTSCotransfection of p-mfgl2shRNA with pEGFP-mfgl2 decreased green fluorescent cells and the lightness of fluorescence within the cells at the 24 h, 48 h and 72 h post-transfection when compared with that in the control groups which were solely transfected with pEGFP-mfgl2. Furthermore the mfgl2 expression was significantly reduced when the pcDNA3.1 mfgl2 expression construct was cotransfected with p-mfgl2shRNA both at mRNA level by RT-PCR and protein level by RT-PCR, immunohistochemistry staining and FACS in both CHO cell and Hela cell lines.

CONCLUSIONSThe study demonstrated that the construct of p-mfgl2shRNA successfully interfered in the mfgl2 expression in vitro. It provides a basis for a further investigation of effect in vivo.

Animals ; Fibrinogen ; biosynthesis ; genetics ; Gene Expression ; Mice ; Plasmids ; genetics ; RNA Interference ; RNA, Small Interfering ; genetics

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 (<0.1 g/L). His young sister and parents showed slightly prolonged TT (18.20-18.50 s) and decreased fibrinogen activity (1.27-1.54 g/L) and fibrinogen antigenic content (1.34-1.56 g/L). Genetic testing revealed that the proband has carried homozygous IVS7-12A>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.
Adult ; Afibrinogenemia/genetics* ; Female ; Fibrinogen/genetics* ; Heterozygote ; Humans ; Male ; Mutation ; Pedigree

Inherited afibrinogenemia is a rare autosomal recessive bleeding disease characterized by complete absence of fibrinogen in blood. To identify the genotype in a Chinese family with inherited afibrinogenemia, the samples of peripheral blood were collected from 6 members of 3 generations. The activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (Fg, clauss) were tested. Fg was also analyzed by using immunoturbidimetry method. DNAs of six members were extracted by using a DNA extract kit. All the exons and exon-intron boundaries of the three fibrinogen genes were amplified by using PCR and analyzed by direct sequencing. The results showed that the parents of proband were 3 degree consanguinity. A homozygous c.934_935insA in FGA was found in proband which results in the change of protein p.Ser312fsX42. The parents, grandmother, maternal grandmother and father's sister were all detected with heterozygous mutation which was same as that in proband. In conclusion homozygous c.934_935insA in FGA is a cause of inherited afibrinogenemia and a novel mutation being reported.
Afibrinogenemia ; etiology ; genetics ; Child ; Exons ; Female ; Fibrinogen ; genetics ; Frameshift Mutation ; Heterozygote ; Humans ; Male ; Pedigree

OBJECTIVETo explore the genetic basis for a Chinese pedigree affected with congenital hypofibrinogenamia.

METHODSPeripheral 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.

RESULTSThe 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.

CONCLUSIONThe heterozygous Ser313Ile mutation probably underlies the hypofibrinogenemia in this pedigree.

Adult ; Afibrinogenemia ; genetics ; Female ; Fibrinogen ; chemistry ; genetics ; Heterozygote ; Humans ; Male ; Middle Aged ; Mutation ; Pedigree

OBJECTIVEThe results of studies on association between -148C/T polymorphism in promoter region of beta-fibrinogen gene and susceptibility to cerebral infarction in Chinese population are controversial. In this study, we summarize the results of published works in this field by a meta-analysis. Data sources Genetic association studies evaluating the beta-fibrinogen gene -148C/T polymorphisms and cerebral infarction involving Chinese population published before December 2005 were collected from PubMed, EMBASE and CNKI. Study selection Case control studies involving unrelated, Han subjects aged from 18 to 80 years, and the internationally recognized diagnostic standard of cerebral infarction and genotype frequencies in control group consistent with Hardy-Weinberg equilibrium were used. Publication bias was tested by funnel plot and the odds ratios of all studies were combined dependent on the result of heterogeneity test among the individual studies. The software Review Manager (Version 4.2) was used for meta-analysis.

RESULTSEleven studies including 1223 patients and 1433 controls met the selection criteria. There was no heterogeneity among the odds ratios (ORs) of individual studies (chi(2) = 17.82, P = 0.06). The combined OR of susceptibility to cerebral infarction in -148T allele carriers compared to the wild homozygote was 1.32 (95% CI 1.12 to 1.55, P = 0.0008). In the patients with cerebral infarction, the average plasma fibrinogen level of allele T carrier was 0.42 g/L (95% CI 0.29 to 0.54, P < 0.001), higher than that of -148C/C homozygous ones.

CONCLUSIONSbeta-fibrinogen gene -148C/T polymorphism might contribute to susceptibility to cerebral infarction in Han Chinese. To reach a definitive conclusion, further gene to gene and gene to environment interactions studies on beta-fibrinogen polymorphisms and cerebral infarction with large sample size are required.

Cerebral Infarction ; genetics ; China ; ethnology ; Fibrinogen ; analysis ; genetics ; Genetic Predisposition to Disease ; Humans ; Polymorphism, Genetic