Analysis of inherited dysfibrinogenemia pedigree associated with a heterozygous and deletion mutantion in the FGG gene / 中华检验医学杂志

Objective To analyze the phenotype and genotype of inherited dysfibrinogenemia pedigree associated with a novel heterozygous and deletion mutation in the FGG gene,and to investigate its molecular mechanism.Methods The clinical data were collected from the proband found at our hospital and her family members in April 2016.The activity plasma fibrinogen(Fg:C), activated partial thromboplastin time(APTT),prothrombin time(PT), thrombin time(TT)were detected by coagulation method and the antigen plasma fibrinogen(Fg:Ag), D-Dimer(D-D), fibrinogen degradation products (FDPs)were analyzed by immunoturbidimetry method.All of the exons and exon-intron boundaries of the genes of FGA, FGB and FGG with the fibrinogen(Fg)were amplified by PCR and followed by direct sequencing.And further verification were performed by cloning sequence and non-denatured polyacrylamide gel electrophoresis and silver staining.The conservatism of mutated gene locus were analyzed by ClustalX-2.1-win.The change of the protein spatial structure and the intermolecular forces with mutation were analyzed by Pymol.Results The Fg:C of the proband was significantly reduced(0.30 g/L)and the Fg:Ag of the proband was normal(2.00 g/L).Their Fg:C were both significantly reduced and the Fg:Ag were both normal(0.42 g/L,2.09 g/L & 0.47 g/L,2.42 g/L, respectively), these were found in her mother and grandma.Genetic analysis revealed a novel heterozygous and deletion mutation with c.944 _c.952 delCCTTTGATG in exon 8 of FGG gene in the proband,predicting a heterozygous 289_291delAla,Phe,Asp mutation.The same mutations were carried by her mother and grandma, but her father and grandpa were normal.Homology analysis indicated that the Ala 289,Phe290 and Asp291 were maintained highly conservative in homogenous species.Protein model analysis found that the original hydrogen bonds were disappeared when the deletion mutation happened with the Ala 289,Phe290 and Asp291.Conclusion The heterozygous and deletion mutation with 289_291delAla,Phe,Asp in the γchain of fibrinogen were identified that could cause the rearrangement of the Fg molecular space structure and the reduction of the structure stability,so the mutation probably underly the dysfibrinogenemia in this pedigree.(Chin J Lab Med,2018, 41:305-311)

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>

Phenotype and genotype analysis for a consanguineous pedigree with combined coagulation factor VII and X deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutations and explore the molecular mechanism underlying combined inherited coagulation factors VII(FVII) and X(FX) deficiency for a family featuring consanguineous marriage between maternal cousins.</p><p><b>METHODS</b>Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, FVII activity (FVII:C), FX activity (FX:C), FVII antigen (FVII:Ag), FX antigen (FX:Ag) and other coagulant parameters of the proband and 5 family members were measured. Potential mutations in exons, exon-intron boundaries and 5', 3' untranslated sequences of F7 and F10 genes were screened by polymerase chain reaction and direct sequencing. Suspected mutations were confirmed by sequencing the opposite strand.</p><p><b>RESULTS</b>PT and APTT of the proband were obviously prolonged to become 76.4 s and 60.2 s, respectively. FVII:C, FVII:Ag,FX:C and FX:Ag of the proband were obviously reduced to become 4%, 6%, 6% and 33%, respectively. Both PT and APTT of her grandmother, father, mother and daughter were slightly prolonged, which have measured 16.4 s, 15.8 s,16.9 s, 16.5 s, and 44.0 s, 42.1 s, 41.1 s, 43.5 s, respectively. And their FVII:C (34%, 39%, 31%, 40%, respectively), FX:C (50%, 58%, 47%, 42%, respectively) and FX:Ag (51%, 54%, 58%, 47%, respectively) were slightly reduced, while FVII:Ag was in the normal range. The coagulant parameters of her younger brother were within normal range. Two homozygous mutations, g.11267C to T in exon 8 of F7 gene, which resulted in an Arg277Cys substitution, and g.28139G to T in exon 8 of F10 gene which led to a Val384Phe substitution, were identified in the proband. The proband's grandmother, parents and daughter were heterozygous for both Arg277Cys and Val384Phe mutationss. Wild-type alleles of both F7 and F10 genes were also found in the younger brother.</p><p><b>CONCLUSION</b>A homozygous Arg277Cys mutation and a Val384Phe mutation have been respectively identified in the F7 and F10 genes, which can explain the low levels of FVII and FX in this family. The former has been inherited from the consanguineous parents.</p>

Molecular mechanism of a pedigree with inherited coagulation factor Ⅶ deficiency / 中华检验医学杂志

Objective To identify gene mutations and explore the molecular mechanism of a pedigree with inherited coagulation F Ⅶ deficiency. Methods The levels of F Ⅶ: Ag in the proband and other family members were measured by ELISA assay. The values of PT, F Ⅶ: C and other coagulant parameters were determined by one-stage clotting for laboratory phenotype diagnosis. All the exons,exon-intron boundaries and 5',3' untranslated sequences of F7 gene were amplified by direct sequencing. The detected mutations were further confirmed by sequencing the other stand. The CLC Protein Workbench software was used to analyze the species conservation of the mutated site and the protein secondary structure. 100 healthy individuals were selected to exclude gene polymorphism. Results PT, FⅦ∶C and FⅦ: Ag in the proband and his sister were abnormal, which were 36. 3 s, 5.0%, 40. 7% and 33.4 s,5. 0%, 37.4%, respectively. Both PT and FⅦ∶C in the proband's father, mother, daughter and niece were slightly abnormal, which were 14.9 s, 14. 6 s, 15.5 s, 14. 6 s and 70%, 85%, 59%, 79%, respectively.The heterozygous mutations c. 784T ＞ C and c. 964T ＞ G in exon 8 of F7 gene were found in the proband,resulting in the substitutions of Ser269Pro and Cys329Gly respectively. Compound heterozygous mutations c. 784T ＞ C and c. 964T ＞ G were found in the proband's sister. The proband's mother was heterozygous for c. 784T ＞ C. His father, daughter and niece were heterozygous for c. 964T ＞ G. The protein biological characteristics analysis revealed that the Cys329Gly caused the change of spatial configuration, and Ser269Pro led to the change of amino acid polarity and hydrophobicity. Conclusion Compound heterozygous mutations of Cys329Gly and Ser269 Pro in F7 gene may be the underlying molecule mechanism of FⅦ deficiency in this pedigree.

The variety of the neutrophil volume and cytoplasm-nucleus complex and their significance in acute bacterial infection and stringency diseases / 中华检验医学杂志

Objective To investigate the variety and clinical value of the neutrophil volume and cytoplasm-nucleus complex in patients with bacterial infection, cardiovascular or cerebrovascular accident and major surgery operation. Methods 125 patients with bacterial infection, 64 patients with acute cardiovascular or cerebrovascular accident, 66 patients after major surgery operation and 69 normal subjects were selected in the study. Total WBC counts (WBC), percentage of neutrophils (NE), and the VCS parameters of neutrephils including the mean channels of cell volume ( NEV), conductivity ( NEC), light scatter(NES) and the SD of these parameters( NEVSD, NECSD, NESSD)were measured by automatic blood cell analyzing instrument. The sensitivity and specificity of the WBC, NE and the VCS parameters of neutrophils were analyzed with receive operating characteristic (ROC) curve. Results The levels of NEV, NES and NEVSD in acute bacterial infection group were 154.3 ± 15.2, 135.7 ± 9.9, 26.8 ± 4.2 respectively. The levels of NEV, NES and NEVSD in post major surgery operation group were 147.2±8.9, 141.5 ± 7.7, 23.0 ± 2. 8 respectively. The levels of NEV, NES and NEVSD in acute cardiovascular or cerebruvascular accident group were 144.9 ± 5. 2, 146.0 ±5.0, 19. 6±1.6 respectively. The levels of NEV, NES and NEVSD in healthy control group were 139.7±4.6, 145.0±3.8, 18.2±1.3 respectively. The differences of these parameters among these groups had statistical significance ( F = 17. 650, 38. 122, 54. 604,P<0. 05). And the changes of NEV, NES and NEVSD in bacterial infection group were most obvious among those three groups. The levels of NEV, NES and NEVSD were 146.5±9.5, 144.3 ± 9.4, 21.3 ± 3.3 respectively in stress diseases groups which included acute cardiovascular or cerebrovascular accident group and post major surgery operation group. The differences of these parameters between stress diseases group and acute bacterial infection group had statistical significance ( t = - 2.840, 7.533, - 8.999,P<0.01). The areas under the ROC curve of NEVSD, NEC, NES and NECSD were 0.893, 0. 845, 0. 833 and 0. 849 respectively. The sensitivity of 83. 3% and specificity of 82. 0% could be achieved by selecting the cut-off equal to or greater than 24. 0. Conclusions The variety of neutrophil volume, nuclear size and cytoplasmic granularity changed obviously in patients with acute bacterial infection and common stress diseases, and the variety in acute bacterial infection is more obvious than that in common stress diseases. The sensitivity and specificity of VCS parameters of neutrophils are higher than those of WBC or NE for predicting infection, and the NEVSD is the most predictable indicator of acute bacterial infection.