Rare inherited coagulation disorders(RCD) are defined as diseases caused by deficiency of coagulation factor/factors, other than factor Ⅷ,factor Ⅸ or von Willebrand factor.RCD are mainly autosomal recessive inheritance disorders with prevalences from 1 in 50 0000 to 1 in 200 0000.The clinical manifestations of RCD are heterogeneous, mainly characterized by bleeding, but thrombosis or no clinical manifestations can also occur. Accurate understanding and diagnosis of RCD is of great significance for clinical treatment.

Objective:To study the clinical and molecular characteristics of a family with familial hypercholesterolemia (FH) with LDLRAP1 and ABCG8 gene abnormality.Methods:In September 2020, one case of FH was included in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine; peripheral venous blood samples of members of the family were collected to detect serum total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) indicators; use high-performance liquid chromatography to detect serum stigmasterol and sitosterol content; perform second-generation gene sequencing to detect gene mutations in probands and family members; use Pymol software to detect gene mutations point for pathogenicity analysis, and use Uniprot Modelling software to perform protein structure modeling.Results:The patient presented with anemia, multiple xanthomas and early-onset acute coronary syndrome. The coronary angiography showed severe coronary artery lesions; abdominal ultrasound showed splenomegaly; blood smear showed shaped erythrocytes and large platelets. The level of serum TC, LDL-C, stigmasterol and sitosterol was 8.54 mmol/L (2.3-5.7 mmol/L), 4.84 mmol/L (range of normal value 1.3-4.3 mmol/L), 44 μmol/L (1.0-10 μmol/L), 28 μmol/L (1.0-15 μmol/L), respectively; LDLRAP1 gene mutation was found: exon4 c.415C>T:p.Q139X; the truncated protein formed by this homozygous mutation lost multiple stable protein structure regions, which can not have a normal function. At the same time, ABCG8 gene mutations were also found: exon13 c.1895T>C (p.V632A) and exon8 c.1199C>A:p.T400K . Two cases of family members had a mild increase in HDL-C (Ⅱ5: 2.33 mmol/L, Ⅱ6∶2.96 mmol/L), 3 cases carrying the ABCG8 gene mutations had a slight increase in stigmasterol (Ⅱ8: 23 μmol/L, Ⅱ7: 24 μmol/L, Ⅰ2: 18 μmol/L) and sitosterol (Ⅱ8: 41 μmol/L, Ⅱ7: 33 μmol/L, Ⅰ2: 45 μmol/L), suggesting that its association with the concentration of plant sterols. Conclusions:FH patients with LDLRAP1 and ABCG8 gene abnormalities may have abnormal plant sterol concentrations, and their clinical manifestations are more complicated. Therefore, family history, LDL-C, plant sterol levels, and genetic test results should be considered comprehensively.

Objective:To analyze the phenotype and genotype of a Chinese pedigree with congenital dysfibrinogenemia and investigate the molecular mechanism of the disease.Methods:Pedigree analysis. Peripheral blood samples were collected from 7 members of the pedigree and routine coagulation tests were conducted. The activity of fibrinogen was measured using Clauss method, and fibrinogen antigen was measured by immunoturbidimetry. All the exons and exon-intron boundaries of FGA, FGB and FGG genes were amplified using PCR, which was followed by direct sequencing. Electrophoretic and immunological analysis of fibrinogen, fibrinogen clottability measurement, fibrin polymerization measurement and scanning electron microscopy were used to investigate the pathogenesis of this disease. Results:The proband showed normal activated partial thromboplastin time (APTT) , prolonged prothrombin time(PT), thrombin time (TT),and reptilase time (RT).The antigen level of fibrinogen in the proband (1.6 g/L) decreased slightly, while the activity level of fibrinogen (0.7 g/L) decreased significantly. His father and grandmother showed normal APTT and PT, prolonged TT and RT. The antigen levels of fibrinogen in both of them were normal (2.0 g/L and 2.2 g/L, respectively), while the activity levels of fibrinogen were low (1.0 g/L and 1.1 g/L, respectively). The results of other members from the pedigree were all within the normal range. Genetic analysis revealed a heterozygous A>G mutation at nucleotide 4774 in exon 6 of FGG gene in the proband, which was predicated to be a novel Gln195Arg mutation. The mutation was also found in his father and grandmother.Western blot results showed that no abnormal bands of plasma fibrinogen were found in the proband, his father and grandmother. The fibrinogen clottability in the proband was 49.3%, while that in the heathy control was 98.9%. Both thrombin-induced fibrin polymerization and reptilase-induced fibrin polymerization were significantly impaired in the proband, compared to that in the heathy control. Scanning electron microscopy revealed that compared with the heathy control, the average fiber diameters of the fibrin clot in the proband increased significantly ( P<0.001), while the density of fibers decreased and the arrangement of fibers was sparse. Conclusions:The heterozygous Arg19Gly mutation, which probably damages functions of fibrinogen, should be responsible for the congenital dysfibrinogenemia in this pedigree. This mutation has not been reported.

Objective: To analyze the phenotype and genotype of a Chinese pedigree with inherited dysfibrinogenaemia and investigate the molecular mechanism of the disease. Methods: Venous blood samples were collected from all family members, and routine coagulation tests were conducted. Functional fibrinogen in venous blood samples was measured by Clauss method, and the antigen level of fibrinogen in plasma was measured by immunoturbidimetry assay. All the exons and exon-intron boundaries of the three fibrinogen genes were analyzed by direct sequencing. Fibrinogen electrophoresis, fibrinogen clottability measurement, fibrin polymerisation measurement and electron microscopy scanning were also used to investigate the molecular characteristics and pathogenesis. Results: The proband had normal activated partial thromboplastin time, prothrombin time and plasma fibrinogen antigen, but prolonged thrombin time, prolonged reptilase time and reduced fibrinogen activity level, which were also found in his father. The sequencing results of the proband revealed heterozygous A1211G in the exon 2 of FGA gene originating from his father, which caused Arg19Gly missense mutation. The western-blot results showed that no abnormal bands of plasma fibrinogen were found in the proband and his father. Both thrombin-induced fibrin polymerisation and reptilase induced fibrin polymerisation were significantly impaired compared to normal control. Fibrinogen clottability measurement showed that only about 20.8% molecules of plasma fibrinogen in the proband were involved in the clot formation. Scanning electron microscopy revealed that the proband′s average fibre diameters were found to be significantly thicker than that of the control(P＜0.001), and the density was smaller than that of normal control. Conclusion The Arg19Gly mutation should be responsible for the proband′s dysfibrinogenaemia and the relevant clinical symptoms.

Anemia, Sideroblastic ; diagnosis ; genetics ; Asian Continental Ancestry Group ; Genetic Diseases, X-Linked ; diagnosis ; genetics ; Humans ; Pedigree

OBJECTIVETo perform phenotypic diagnosis, genetic diagnosis and prenatal diagnosis of inherited coagulation factor XIII (FXIII)deficiency in a Chinese family also provide a review of inherited coagulation F XIII deficiency.

METHODSThe activity levels of F XIII (F XIII:C) of proband and family members were measured by clot solubility test and REA-chrom F XIII kit. The antigen levels of F XIII(FXIII:Ag) were measured by enzyme-linked immunosorbent assay. Thrombelastography (TEG) test was used to make a comprehensive evaluation of coagulation status in the proband. All 15 exons and exon-intron boundaries of the F13A1 gene were amplified by PCR, and DNA sequencing was performed then. The mutation identified in the proband was screened in the family members. Furthermore, the related literatures were reviewed to provide a profile of clinical manifestation, gene mutations, the relationship between the mutations and phenotype, and treatments of inherited coagulation F XIII deficient cases.

RESULTSThe clot solubility test was positive in the proband. The FXIII:Ag level of the proband was less than 1% and the FXIII:C level was below the lower limit of detection (<3%). Two compound heterozygous missense mutations (p.Arg662* and p.Trp665*) were identified in the proband. Family study showed that the two mutations were both inherited from the parents. The fetus also carried two compound heterozygous mutations, the same as the proband, and was diagnosed with severe F XIII deficiency. As reported in the literatures, most mutations were missense mutations and nonsense mutations, and no hot spot was found. The clinical pattern of F XIII deficiency varied among patients, with potentially fatal consequences from severe bleeding complications.

CONCLUSIONBetter understanding of F XIII biochemical properties and function and developing of FXIII laboratory assays and genetic detection could prevent missed diagnosis, and patients moght benefit from better care.

Asian Continental Ancestry Group ; Base Sequence ; DNA Mutational Analysis ; Enzyme-Linked Immunosorbent Assay ; Exons ; Factor XIII ; genetics ; Factor XIII Deficiency ; genetics ; Female ; Heterozygote ; Humans ; Introns ; Mutation, Missense ; Pedigree ; Phenotype ; Polymerase Chain Reaction ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo study the molecular mechanisms of inherited antithrombin (AT) deficiency caused by AT L99 mutation.

METHODSWild type (WT), L99V, L99A, L99I and L99S AT were purified from drosophila expression system. The binding capacity of AT and the low molecular weight heparin sodium was analyzed by the heparin binding assay. Surface plasmon resonance (SPR) was used to detect the binding ability of AT to thrombin (FIIa) or AT to coagulation factor Xa (FXa). The activity of AT(AT∶A)was detected by chromogenic assay.

RESULTSThe purified WT and mutant AT were at the same size. No additional band was observed by coomassie blue staining and western blot assay. Compared to the WT AT, the binding abilities of the low molecular weight heparin sodium to the AT L99V, L99A, L99I and L99S were (44.8±3.6)%, (118.9±14.0)%, (15.2±8.8)%, and(23.0±8.2)%, respectively. The binding abilities of FIIa to AT L99V, L99A, L99I and L99S were 13%, 57%, 3%, and 29%, while the binding of FXa to AT L99V, L99A, L99I and L99S were 7%, 51%, 1%, and 25%. The AT∶A of WT, L99V, L99A, L99I and L99S AT were 146.5%, 21.4%, 120.9%, 10.8%, and 39.0%, respectively.

CONCLUSIONThe binding abilities of AT to heparin, FIIa and FXa were damaged by the L99 mutation, which resulted in decreased AT∶A and inherited AT deficiency.

Amino Acids ; genetics ; Animals ; Antithrombin III ; genetics ; Antithrombin III Deficiency ; genetics ; Antithrombins ; Drosophila ; Factor Xa ; genetics ; Genetic Vectors ; Humans ; Mutation

OBJECTIVETo disclose the impact of Trp1707Ser mutation on the binding mechanism of rFVIII light chain (rFVIII LC) with VWF.

METHODSUsing long-chain PCR technique, we constructed rFVIII LC plasmids of both wild type and Trp1707Ser mutant type. BL21 competent cells were used for protein expression. Gradient renaturation was employed to refold protein. SDS-PAGE and Western blot were performed to identify the molecular weight of expressed protein. GST-Sefinose was used for protein purification and surface plasmon resonance (SPR) was employed to detect binding of B-domain-deleted rFVIII (BDD-rFVIII), wild and mutant rFVIII LC with VWF, respectively.

RESULTSThe results of SDS-PAGE and Western blot showed a molecular weight of 110×10(3) of expressed proteins, which were consistent with objective proteins. The expression quantity of wild type was higher than that of mutant type. A concentration-dependent combination of the 3 testing proteins with VWF was found. The KD value of BDDrFVIII (12.2) was lower than that of both rFVIII LCs (wild type 48.9 and mutant type 46.3), whereas there was no discrepancy between wild rFVIII LC and mutant rFVIII LC.

CONCLUSIONTrp1707Ser mutation didn't impact the binding of rFVIII LC expressed by BL21 competent cells with VWF. The heavy chain played a more important role in impacting the binding of FVIII with VWF.

Mutation ; von Willebrand Factor ; genetics

Objective To analyze the phenotype and genotype of a Chinese family with inherited hypofibrinogenemia,and to investigate its molecular mechanism.Methods Peripheral blood was collected from seven people of this family and then plasma was separated.Activated partial thromboplastin time ( APTT),prothrombin time ( PT),thrombin time ( TT),reptilase time ( RT),the activities of antithrombin( AT∶ A ),protein C ( PC ∶ A ) and protein S ( PS ∶ A ) were tested.The activity and antigen of plasma fibrinogen were analyzed by Clauss method and immunoturbidimetry method,respectively.The fibrinogen peptide chain of the proband was semiquantitatively assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).Thrombin generation test was performed by calibrated automated thromhogram.The dynamic process of blood coagulation was evaluated by the thrombelastography (TEG).Genomic DNA was extracted from the peripheral blood.The sequences of all the exons and exon-intron boundaries of the three fibrinogen genes FGA,FGB and FGG were amplified by polymerase chain reaction ( PCR ) and analyzed by direct sequen(c)ing.Results The activity and the antigen levels of the proband' s plasma fibrinogen were reduced to 0.48 g/L and 0.68 g/L,respectively.TT prolonged to 29.2 s and RT prolonged to 75.8 s.The assays of SDS-PAGE showed no abnormal molecular weight of fibrinogen.Peak height of thrombin generation was reduced to 249.93 nmol/L and endogenous thrombin potential was reduced to 1007.0 nmol · L-1 · min.Hypocoagulability state of the whole blood was found by TEG test.The coagulation index was - 8.6.The proband was diagnosed as inherited hypofibrinogenemia by phenotype analysis.Two mutations (Gln143Pro and g.4642delC) were found in the proband's fibrinogen Aa-chain gene,Gln143Pro came from her mother and g.4642delC came form her father.Conclusion Compound Heterozygous Mutations (Gln143Pro and g.4642delC ) of fibrinogen Aa-chain causes the proband congenital hypofibrinogenemia.

Objective To analyze the phenotype and genotype of three patients with yon Willebrand disease (vWD),and to explore its molecular pathogenesis.Methods Bleeding time (BT),APTT,ristocetin induced platelet aggregation (RIPA),von Willebrand factor (vWF):ristocetin cofactor (Rco)(vWF∶ Rco),vWF antigen (vWF∶ Ag),vWF activity (vWF∶ A) test,vWF collagen binding assay (vWF∶ CB) and multimer analysis were detected for phenotype diagnosis.The dynamic process of blood coagulation was evaluated by using the thrombelastography.Genomic DNA was extracted from the peripheral blood.The vWF gene mutation was detected by sequencing.Results APTT,BT were prolonged in the three probands.Plasma vWF∶ Rco,vWF∶ Ag,vWF∶ A and vWF∶ CB were decreased in different degrees.RIPA was reduced in probands B and C.vWF multimer analysis found the lost of the large molecular weight multimers in proband B,while basically normal in probands A and C.The dynamic process of blood coagulation of proband C presented obvious hypocoagulability by using the thrombelastography.Heterozygous missense mutation g.106782G ＞ T resulting in Cys1130Phe in exon 26,g.110988G ＞ A resulting in Gly1579Arg in exon 28 and g.110373C ＞T resulting in Arg1374Cys in exon 28 were found in the probands A,B and C,respectively.Conclusion Three probands were diagnosed as type 1,type 2A or type 2MvWD by phenotype detection.Heterozygous missense mutation Cys1130Phe,Gly1579Arg and Arg1374Cys induced vWD of three probands,respectively.