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.
Afibrinogenemia ; genetics ; Blood Coagulation Disorders ; genetics ; Humans ; Mutation

OBJECTIVETo investigate the gene defect in a hereditary coagulation factor V (FV) deficiency family.

METHODSThe plasma FV actigen was measured by one-stage clotting assay. The FV antigen was assayed by Biotin-Avidin enzyme linked immunosorbent assay (BA-ELISA). The full length of exon 1 to exon 25 and the 5' untranslated sequence of FV genomic DNA were analyzed by polymerase chain reaction (PCR) and direct sequencing of the amplified fragments, meanwhile the defect was identified by T/A cloning sequencing.

RESULTSThe plasma coagulant activity and amount of FV of the proband were marked deficient (1% and 1.54%, respectively). DNA sequence analysis for the proband revealed a causative mutation in a heterozygous status. It was one base pair deletion in exon 4 at nucleotide 675 inherited from her mother.

CONCLUSIONSA novel mutation in the FV gene was identified in the proband with congenital FV deficiency. The mutation was 675delA in exon 4 resulting in a frameshift and a premature termination codon.

Adolescent ; Blood Coagulation ; Factor V ; analysis ; genetics ; Factor V Deficiency ; blood ; genetics ; Female ; Humans ; Mutation

OBJECTIVETo investigate the gene mutations in a pedigree with inherited prothrombin (FII) deficiency.

METHODSThe activated partial thromboplastin time (APTT), prothrombin time (PT), FII activity (FII:C) and FII antigen (FII:Ag) test were used for phenotype diagnosis. The genomic DNA was extracted from the peripheral blood of the propositus. All the 14 exons, intron/exon boundaries and the 5' and 3' untranslated regions (UTR) of the prothrombin gene were amplified by polymerase chain reaction (PCR). The PCR products were screened by direct sequencing and the mutations detected were further confirmed by restricted enzyme digestion. One hundred and three healthy blood donors were used as controls.

RESULTSThe phenotype of the propositus was prothrombin deficiency (type I). With reference to the prothrombin nucleotide sequence published by Degen & Dacie, three variations were found in the FII gene of the propositus. Among them, the novel mutation was a homozygous A601G subtitution in exon 2.

CONCLUSIONThe prothrombin deficiency of the propositus is caused by a homozygous Glu29 to Gly mutation in the prothrombin gene.

Blood Coagulation ; Child ; Female ; Humans ; Hypoprothrombinemias ; blood ; genetics ; Point Mutation ; Prothrombin ; genetics

OBJECTIVE: To screen better promoters and provide more powerful tools for basic research and gene therapy of hemophilia. METHODS: Bioinformatics methods were used to analyze the promoters expressing housekeeping genes with high abundance, so as to select potential candidate promoters. The GFP reporter gene vector was constructed, and the packaging efficiency of the novel promoter was investigated with EF1 α promoter as control, and the transcription and activities of the reporter gene were investigated too. The activity of the candidate promoter was investigated by loading F9 gene. RESULTS: The most potential RPS6 promoter was obtained by screening. There was no difference in lentiviral packaging between EF1 α-LV and RPS6-LV, and their virus titer were consistent. In 293T cells, the transduction efficiency and mean fluorescence intensity of RPS6pro-LV and EF1 αpro-LV were proportional to the lentiviral dose. The transfection efficiency of both promoters in different types of cells was in the following order: 293T>HEL>MSC; Compared with EF1 αpro-LV, RPS6pro-LV could obtain a higher fluorescence intensity in MSC cells, and RPS6pro-LV was more stable in long-term cultured HEL cells infected with two lentiviruses respectively. The results of RT-qPCR, Western blot and FIX activity (FIX∶C) detection of K562 cell culture supernatant showed that FIX expression in the EF1 α-F9 and RPS6-F9 groups was higher than that in the unloaded control group, and there was no significant difference in FIX expression between the EF1 α-F9 and RPS6-F9 groups. CONCLUSION After screening and optimization, a promoter was obtained, which can be widely used for exogenous gene expression. The high stability and viability of the promoter were confirmed by long-term culture and active gene expression, which providing a powerful tool for basic research and clinical gene therapy of hemophilia.
Humans ; Transduction, Genetic ; Genetic Vectors ; Hemophilia A/genetics* ; Transfection ; Blood Coagulation Factors/genetics* ; Lentivirus/genetics*

Objective To investigate the correlation between the polymorphism of 4 coagulation-related genes, rs1799963 （coagulation factor V gene Leiden）, rs6025 （prothrombin gene G20210A）, rs1042579 （thrombomodulin protein gene c.1418C>T） and rs1801131 （methylenetetrahydroflate reductase gene） and lower extremity deep venous thrombosis （LEDVT）. Methods The 4 genotypes mentioned above of 150 LEDVT patients and 153 healthy controls were detected by the kompetitive allele specific polymerase chain reaction （KASP）, then related blood biochemical indicators were collected, binary Logistic regression was established to screen the independent risk factors of LEDVT, and the correlation between polymorphism of 4 coagulation-related genes and LEDVT and its indicators under different genetic modes after adjusting confounding factors were analyzed. Results Five variables, D-dimer, fibrinogen degradation product, homocysteine, sex and age might be the risk factors of LEDVT. These variables were put into 4 genetic inheritance models, and adjusted in binary Logistic regression. The results suggested that the mutations of rs1042579 were correlated with LEDVT under dominant inheritance mode. Conclusion The gene polymorphism of rs1799963, rs6025 and rs1801131 has no significant correlation with the formation of LEDVT. The gene polymorphism of rs1042579 plays a role under dominant inheritance mode, and might be an independent risk factor for formation of LEDVT.
Blood Coagulation/genetics* ; Humans ; Lower Extremity ; Polymorphism, Genetic ; Risk Factors ; Venous Thrombosis/genetics*

Adolescent ; Adult ; Aged ; Blood Coagulation ; Factor XII ; genetics ; Factor XII Deficiency ; blood ; genetics ; Female ; Humans ; Male ; Point Mutation

OBJECTIVETo determine the cut-off value for coagulation factor Ⅷ activity (FⅧ:C) to von Willebrand factor antigen (vWFAg) ratio which can classify obligatory carriers of hemophilia A and normal females, and assess its feasibility to diagnose suspected carriers in affected families through comparison with the method of gene diagnosis.

METHODSFⅧ:C assay was carried out by a one-stage method in both obligatory carriers and normal females. vWF antigen was measured with ELISA assay. The FⅧ:C/vWF ratio was calculated. Statistic analysis was carried out to determine the cut-off value which can classify the two groups. The ratio was then used to diagnose suspected carriers from families affected with hemophilia A. The results were compared with that by long distance polymerase chain reaction, genetic linkage analysis and/or direct sequencing.

RESULTSThe FⅧ:C/vWFAg value for 90.6% of obligatory carriers was under 0.82. Should 0.82 be selected as the cut-off value to diagnose the 42 suspected carriers, most of them can be readily diagnosed. The results were all in agreement with that of genetic analysis.

CONCLUSIONCut-off value of FⅧ:C/vWFAg may be used for initial diagnose of the suspected carriers from families affected with hemophilia A. The method is quite convenient and reliable.

Blood Coagulation Tests ; methods ; Factor VIII ; genetics ; Female ; Genetic Linkage ; Hemophilia A ; diagnosis ; genetics ; Humans ; Male ; von Willebrand Factor ; genetics

OBJECTIVE: To analysis clinical phenotype and potential genetic cause of a family affected with hereditary coagulation factor Ⅻ deficiency. METHODS: The prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-Dimer (D-D), coagulation factor Ⅻ activity (FⅫ:C) and coagulation factor Ⅻ antigen (FⅫ:Ag) were determined for phenotype diagnosis of the proband and his family members(3 generations and 5 people). Targeted capture and whole exome sequencing were performed in peripheral blood sample of the proband. Possible disease-causing mutations of F12 gene were obtained and further confirmed by Sanger sequencing. The corresponding mutation sites of the family members were analyzed afterwards. The online bioinformatics software AutoPVS1 and Mutation Taster was used to predict the effects of mutation sites on protein function. RESULTS: The APTT of the proband was significantly prolonged, reaching 180.9s. FⅫ:C and FⅫ:Ag of the proband was significantly reduced to 0.8% and 4.17%, respectively. The results of whole exome sequencing displayed that there were compound heterozygous mutations in F12 gene of the proband, including the c.1261G＞T heterozygous nonsense mutation in exon 11 (causing p.Glu421*) and the c.251dupG heterozygous frameshift mutation in exon 4 (causing p.Trp85Metfs*53). Both mutations are loss of function mutations with very strong pathogenicity, leading to premature termination of the protein. AutoPVS1 and Mutation Taster software predicted both mutations as pathogenic mutations. The results of Sanger sequencing revealed that c.1261G＞T heterozygous mutation of the proband was inherited from his mother, for which his brother and his daughter were c.1261G＞T heterozygous carriers. Genotype-phenotype cosegregation was observed in this family. CONCLUSION The c.1261G＞T heterozygous nonsense mutation in exon 11 and the c.251dupG heterozygous frameshift mutation in exon 4 of the F12 gene probably account for coagulation factor Ⅻ deficiency in this family. This study reports two novel pathogenic F12 mutations for the first time worldwide.
Blood Coagulation Disorders ; Codon, Nonsense ; Factor XII/genetics* ; Female ; Heterozygote ; Humans ; Male ; Mutation ; Pedigree

Thrombophilia that is common among Caucasians is caused by genetic polymorphisms of coagulation factor V Leiden (R506Q) and prothrombin G20210A. Unlike that in Caucasians, thrombophilia that is common in the Japanese and Chinese involve dysfunction of the activated protein C (APC) anticoagulant system caused by abnormal protein S and protein C molecules. Approximately 50% of Japanese and Chinese individuals who develop venous thrombosis have reduced activities of protein S. The abnormal sites causing the protein S molecule abnormalities are distributed throughout the protein S gene, PROS1. One of the most common abnormalities is protein S Tokushima (K155E), which accounts for about 30% of the protein S molecule abnormalities in the Japanese. Whether APC dysfunction occurs in other Asian countries is an important aspect of mapping thrombophilia among Asians. International surveys using an accurate assay system are needed to determine this.
Asian Continental Ancestry Group ; Blood Coagulation ; Blood Proteins/genetics/metabolism ; Humans ; Protein C/genetics/*metabolism ; Protein S/chemistry/genetics/metabolism ; Thrombophilia/epidemiology/*etiology ; Venous Thrombosis/etiology/genetics

OBJECTIVETo investigate the antithrombin (AT) activity (AT: A) and AT antigen (AT: Ag) level in a Chinese family with type I antithrombin (AT) deficiency, and to explore the molecular mechanism of AT deficiency.

METHODSImmuno-nephelometry and chromogenic assay were used to detect the plasma level of AT: A and AT: Ag, respectively. Genomic DNA was isolated from the peripheral blood, and all the seven exons and exon-intron boundaries of AT gene were amplified by PCR and direct sequencing.

RESULTSThe plasma levels of AT: A and AT: Ag of the proband were 45% and 97 mg/L, respectively, which led to a type I AT deficiency. A heterozygous T to A mutation was found at nucleotide 9833 in exon 5 resulting in a Tyr363Stop nonsense mutation. The sequencing results from the pedigree indicated that four other members also had this mutation.

CONCLUSIONThis heterozygous nonsense mutation of T9833A in exon 5 resulting in venous thrombosis is a novel genetic defect of hereditary AT deficiency, which has not been described before.

Antithrombin III Deficiency ; genetics ; Antithrombins ; genetics ; Blood Coagulation Tests ; Female ; Humans ; Male ; Mutation ; Pedigree ; Polymerase Chain Reaction ; Sequence Analysis, DNA