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.

A study on gene mutation of coagulation factor Ⅺ protein secretion disorder and its mechanism / 中华检验医学杂志

Objective:To investigate the molecular pathogenesis of a newly discovered gene mutation in a family with hereditary coagulation factor Ⅺ(FⅪ) deficiency.Methods:The proband was admitted to the First Affiliated Hospital of Wenzhou Medical University in September 2021 due to "calculus of intrahepatic duct". The patient had no symptoms of spontaneous bleeding.The clinical data and blood samples of the proband and her family members (10 persons in 3 generations) were collected.The activated partial thromboplastin time (APTT) and FⅪ activity (FⅪ:C) were performed by the one-stage clotting assay. FⅪ antigen (FⅪ:Ag) were detected by enzyme linked immunosorbent assay (ELISA). Genomic DNA extracted from peripheral blood cells of subjects was used as template to analyze F11 gene mutation by DNA direct sequencing. Bioinformatics software was used to analyze the effects of mutations on protein structure and function. Wild-type and mutant FⅪ protein expression vectors were constructed and transient transfected into HEK293T cells. The total RNA was extracted from positive transfected cells and then reversely transcribed into cDNA. The mRNA expression level of F11 gene in transfected cells was detected by real-time fluorescence quantitative PCR (qRT-PCR). The content of FⅪ:Ag and the expression of FⅪ protein in transfected cell lysates and culture supernatant were detected by ELISA and western blot.Results:The APTT of the proband was significantly prolonged to 107.9s (reference range 29.0-43.0s), while FⅪ:C and FⅪ:Ag were significantly decreased to 2% (reference range 84%-122%) and 5% (reference range 76%-127%), respectively. Gene sequencing analysis indicated that the proband had c.536C>T (p.Thr161Met) heterozygous missense mutation and c.1556G>A (p.Trp501Ter) heterozygous nonsense mutation in exon 6 and 13 of the F11 gene, respectively. Bioinformatics analysis showed that the amino acids at site 161 of FⅪ protein were threonine (Thr) in the matrix composed of five different species, indicating that Thr161 site was highly conserved among homologous genes in different species. p.Thr161Met heterozygous mutation affected the stability of local intermolecular structure of FⅪ protein. In vitro expression experiments of p.Thr161Met mutation showed that FⅪ protein had a normal synthesis in the cells but secretion dysfunction.Conclusions:c.536C>T (p.Thr161Met) heterozygous missense mutation and c.1556G>A (p.Trp501Ter) heterozygous nonsense mutation were mainly responsible for the decrease of FⅪ in this family. p.Thr161Met mutation was first reported in the world and did not affect the normal synthesis of FⅪ protein, but caused secretion dysfunction.

Analysis of two propositas with inherited hypodysfibrinogenemia / 中华检验医学杂志

Objective:To analyze the phenotype and genotype of two propositi with inherited hypodysfibrinogenaemia caused by compound heterozygous mutations, and investigate the molecular mechanism.Metheds:Two propositi and their family members(7 person in 3 generations and 10 person in 3 generations,respectively) were investigated. The activity of plasma fibrinogen (Fg:C) and thrombin time (TT) were analyzed by coagulation method, the antigen of plasma fibrinogen (Fg:Ag) was detected by immunoturbidimetry. All of the exons and flanking sequences of FGA,FGB,FGG of two propositi were amplified by PCR, followed by direct sequencing. The ClustalX-2, 1-win software was used to analyze the conservatism of mutated gene locus. PROVEAN and Mutation Taster were applied to analyze the pathogenicity of mutated amino acid. The changes of the protein spatial structure and intermolecular interaction were analyzed by Pymol.Results:Fg:C and Fg:Ag of proposita A and B were both significantly decreased (0.74 and 0.78 g/L, 0.96 and 0.94 g/L, respectively). Gene analysis revealed that proposita A and B both carried a heterozygous mutation c.2185G>A(p.AαGlu710Lys) in exon 6 of FGA. Furthermore, proposita A also carried a heterozygous mutation c.701G>T(p.γTrp208Leu) in exon 7 of FGG, and proposita B carried a heterozygous mutation c.1015A>C(p.γSer313Arg) in exon 8 of FGG. Phylogenetic analysis suggested that p.AαGlu710,p.γTrp208 and p.γSer313 were highly conserved among homologous species. All variants were predicted to be deleterious by two online bioinformatic softwares. The protein model analysis indicated that protein spatial structure and intermolecular hydrogen bonds were changed by these variants, which destroyed the stability of Fg.Conclusion:The compound heterozygous mutations of p.AαGlu710Lys and p.γTrp208Leu,p.AαGlu710Lys and p.γSer313Arg might account for the hypodysfibrinogenemia in two propositi.

Phenotypic and genotypic analysis of a pedigree affected with hereditary protein C deficiency due to heterozygous deletional mutation of PROC gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the phenotype and genetic variants of a pedigree affected with hereditary protein C (PC) deficiency.@*METHODS@#The protein C activity (PC:A) of the proband and her family members (a four-generation pedigree including 11 individuals) were tested by chromogenic substrate method, and the protein C antigen (PC:Ag) was detected with an enzyme-linked immunosorbent assay(ELISA). The 9 exons and flanking sequences of the protein C (PROC) gene were amplified by PCR and directly sequenced. Suspected mutation was validated by clone sequencing and in other members of the family. MutationTaster and ClustalX-2.1-win was used to analyze the pathogenicity and conservation of the mutation site,respectively. Three-dimentional protein model and amino acids interaction were analyzed with Swiss-PdbViewer software.@*RESULTS@#The PC: A and PC: Ag of the proband were decreased to 46% (reference range: 70%-130%) and 50% (referencerange:70%-140%), respectively. Her grandmother,aunt, cousin and younger brother also showed declined PC:A and PC:Ag by approximately 50%. Genetic analysis revealed that the above individuals have all carried a deletional mutation c.1212-1212delG (p.Met364TrpfsX15) in exon 9 of the PROC gene which can cause replacement of Methionine at position 364 by Tryptophan and alteration of 15 downstream amino acids, and produce a premature stop codon at position 378. The score of MutationTaster was 1.000, indicating that the variant is pathogenic. Conservative analysis showed that the 15 altered amino acids are located in a conserved region across nine homologous species. Protein model analysis showed that the mutation has disrupted a catalytic domain of protein C thereby affected its function.@*CONCLUSION@#The heterozygous c.1212-1212delG deletional mutation in exon 9 of the PROC gene, which was unreported previously,probably accounts for the decrease of PC:A and PC:Ag in this pedigree.

Identification of novel compound heterozygous variants in a pedigree affected with hereditary coagulation factor XI deficiency / 中华医学遗传学杂志

OBJECTIVE@#To analyze the phenotype and genetic basis for a pedigree affected with hereditary coagulation factor XI deficiency.@*METHODS@#Activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (FIB), FXI activity (FXI:C) and the antigen of FXI (FXI:Ag) were determined for the proband and members from his pedigree. Sanger sequencing was used to analyze all exons, exon-intronic boundaries, as well as the 5'- and 3'- untranslated regions of the F11 gene. Suspected variants were verified in her family members and confirmed by reverse sequencing. The impact of the variants on the protein function was predicted by using PolyPhen-2 and SIFT software. The protein structure and amino acid interaction were analyzed by using Swiss-PdbViewer.@*RESULTS@#The APTT, FXI:C and FXI:Ag of the proband and her sister were significantly reduced to 73.0 s, 10.0%, 15.0% and 87.1 s, 2.0% and 11.5%, respectively. APTT of some family members was slightly prolonged, and FXI:C and FXI:Ag also decreased to various extents. DNA sequencing revealed that the proband and her sister have carried compound heterozygous variants of c.738G>A (p.Trp228stop) and c.938G>T (p.Ser295Ile) respectively in exons 7 and 9 of the F11 gene. Her father, sister and daughter were heterozygous for the c.738G>A (p.Trp228stop) variant, while her mother and nephew were heterozygous for the c.938G>T (p.Ser295Ile). Both PolyPhen-2 and SIFT predicted that the p.Ser295Ile variant is likely to be deleterious and can affect the protein function. Modeling analysis indicated that the p.Ser295Ile variant may lead to disruption of a hydrogen bond, resulting in alteration of protein structure and instability.@*CONCLUSION@#The compound heterozygous c.738G>A (p.Trp228stop) and c.938G>T (p.Ser295Ile) variants of the F11 gene probably underlie the decreased FXI level in this pedigree.

Identification of compound heterozygous variants of F12 gene in a pedigree affected with inherited coagulation factor XII deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular pathogenesis for a pedigree affected with hereditary coagulation factor XII (FXII) deficiency.@*METHODS@#Potential variant of the F12 gene was analyzed by PCR and Sanger sequencing. Expression plasmids were constructed by site-directed mutagenesis based on the wild-type and transiently transfected into 293T cells. FXII:C and FXII:Ag of the expression products were determined in the supernatant and cell lysate. Western blotting was used to verify the identify of the protein.@*RESULTS@#Gene sequencing revealed that the proband has carried 46TT genetype and heterozygous p.Glu502Lys variants in exon 13, and a heterozygous p.Gly542Ser variant in exon 14 of the F12 gene. Transfection experiment suggested that the FXII:C and FXII:Ag of p.Glu502Lys variant in the supernatant were 28% and 24%, compared with the wild-type (100%) and FXII:Ag of cell lysates was 39% compared to the wild-type (100%). The FXII:C and FXII:Ag of p. Gly542Ser variant in the supernatant were 32% and 17% and the FXII:Ag of cell lysates was 59%.@*CONCLUSION@#The 46TT genetype, p.Glu502Lys and p.Gly542Ser variants of the F12 gene probably underlie the low FXII level in the proband. As shown by in vitro experiment, the p.Glu502Lys and p.Gly542Ser variants can both inhibit the synthesis and secrection of the FXII protein.

Analysis of a Chinese pedigree affected with hereditary factor VII deficiency caused by compound heterozygous variants of F7 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular basis for a Chinese pedigree affected with hereditary coagulation factor VII (FVII) deficiency.@*METHODS@#The coding regions of F7 gene were amplified by PCR and sequenced. Suspected variants were confirmed by reverse sequencing and validated in other members from the pedigree. Pathogenicity of the variants was analyzed with multiple bioinformatic tools.@*RESULTS@#Genetic analysis revealed that the proband has carried compound heterozygous c.985T>C (p.Ser329Pro) and c.1091G>A (p.Arg364Gln) variants in exon 8 of the F7 gene. Her mother, brother and son were heterozygous for c.985T>C (p.Ser329Pro), while her father was heterozygous for c.1091G>A (p.Arg364Gln). Phylogenetic analysis suggested that both p.Ser329 and p.Arg364 are highly conserved among homologous species. Online bioinformatic software predicted both variants to be deleterious. Protein model analysis suggested that the Pro329 side chain may form a new hydrogen bond with Leu333. The Pro benzene ring may clash with Glu325 in the p.Ser329Pro variant model. The p.Arg364Gln variant have two additional hydrogen bonds compared with wild type Arg364. Both variants may lead to alteration of the protein structure.@*CONCLUSION@#The p.Ser329Pro and p.Arg364Gln variants in exon 8 of the F7 gene probably account for the reduced FVII in this pedigree.

Clinical characteristics and genetic analysis of a combined inherited antithrombin and factor Ⅶ deficiency pedigree / 中华检验医学杂志

Objective:To study the clinical characteristics and gene mutations in a family with combined inherited antithrombin (AT) and factor Ⅶ (FⅦ) deficiency, and explore the relationship between AT gene, F7 gene mutations and diseases. Methods:Pedigree investigation. Blood samplesand clinical dataswere collected fromthe proband and her family members (a total of 16 people in 3 generations) who admitted to the First Affiliated Hospital of Wenzhou Medical University in November 2018. The prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), antithrombin activity (AT: A), antithrombin antigen (AT: Ag), protein C activity (PC: A), protein S activity (PS: A), FⅦ activity (FⅦ: C), FⅦ antigen (FⅦ: Ag) and other indicators were detectedto confirm the diagnosis. DNA direct sequencing analysis of all exons, flanking sequences, 5′ and 3′ untranslated regions of AT genes and F7 genes, and the mutation sites were confirmed by clone sequencingor reverse sequencing. Results:The AT: A and AT: Ag of the proband were 46% and 135 mg/L, respectively (reference range: 250-360 mg/L), some of her family members′ s (father, aunt, two cousins, younger brother and nephew) AT: A and AT: Ag were reduced to 50% of normal range. Her father (Ⅰ 2), aunt (Ⅰ 4), elder brother (Ⅱ 7), younger brother (Ⅱ 8), and nephew (Ⅲ 3)′s FⅦ: C were 45%, 50%, 48%, 47% and 48%, respectively; and their FⅦ:Ag was within the normal range. Genetic analysis revealed that the proband(Ⅱ 6) and some of her family members (father, aunt, two cousins, younger brother and nephew) took rs3138521 polymorphism in the 5′ untranslated region of AT gene. Her father (Ⅰ 2), aunt (Ⅰ 4), elder brother (Ⅱ 7), younger brother (Ⅱ 8), nephew (Ⅲ 3) took c.1091G>A heterozygous missense mutationin exon 8 of F7 gene, resulting in p.Arg304Gln. Conclusion:The rs3138521 in AT gene and c.1091G>A in F7 gene, which may be the molecular mechanism leading to combined inherited AT and FⅦ deficiency in this family.

Phenotypic and genetic analysis of a pedigree affected with hereditary FⅤ deficiency due to a novel deletional variant of F5 gene / 中华医学遗传学杂志

Objective@#To analyze the phenotype and F5 gene variant in a pedigree affected with hereditary coagulation factor Ⅴ (FⅤ) deficiency.@*Methods@#All of the exons, flanking sequences, and 5′ and 3′ untranslated regions of the F5 gene were subjected to PCR and direct sequencing. Suspected variant sites were confirmed by clone sequencing. Influence of the variants was predicted by using software including ClustalX and Mutation Taster.@*Results@#The prothrombin time (PT) and activated partial thromboplastin time (APTT) of the proband were prolonged to 20.3 s and 59.2 s, respectively, while FⅤ activity (FⅤ∶C) and FⅤ antigen (FⅤ∶Ag) were reduced by 13% and 17%, respectively. The FⅤ∶C and FⅤ∶Ag of his father, sister and daughter were decreased to 35%, 37%, 29% and 42%, 46%, 35%, respectively. The proband was found to carry a heterozygous c. 2851delT variant in exon 13 of the F5 gene, which caused a frameshift and resulted in a truncated protein (p.Ser923LeufsX8). In addition, a heterozygous c. 1538G>A (p.Arg485Lys) variant was found in exon 10. The father, sister and daughter of the proband all carried the p. Ser923LeufsX8 variant, while his mother and son carried the heterozygous p. Arg485Lys polymorphism. His younger brother and wife were of the wild type. Bioinformatic analysis showed that p. Ser923 was highly conserved across various species. Mutation Taster scored 1.00 for the p. Ser923LeufsX8 variant, and the result has predicted a corresponding disease.@*Conclusion@#A heterozygous deletional mutation c. 2851delT in exon 13 of the F5 gene and a heterozygous c. 1538G>A polymorphism harbored by the proband may be associated with the decreased FⅤ level in this pedigree.

Genetic analysis and clinical features of a pedigree affected with hereditary coagulation factor Ⅶ deficiency caused by compound heterozygotic mutations / 中华医学遗传学杂志

Objective@#To detect potential mutations of the coagulation factor Ⅶ (F7) gene in a pedigree affected with hereditary FⅦ deficiency and explore its molecular pathogenesis.@*Methods@#The FⅦ antigen (FⅦ∶Ag) was analyzed by an enzyme-linked immunosorbent assay (ELISA) method. Prothrombin time (PT), FⅦ activity (FⅦ∶C) and other coagulant parameters were quantified with an one-stage clotting assay. The F7 gene was amplified by PCR and sequenced. Mutational sites were confirmed by reverse sequencing. Impact of amino acid substitution was assessed using SIFT and PolyPhen-2 software. Structure of the mutant protein was analyzed using Swiss-pdb Viewer software based on the three-dimensional structure in the Protein Data Bank.@*Results@#The propositus had prolonged PT (36.3 s), with FⅦ∶C and FⅦ∶Ag significantly reduced to 2% and 44%, respectively. Her father, mother, younger sister and daughter had slightly prolonged PT and reduced FⅦ∶C (86%-120%). The FⅦ∶Ag of her father and younger sister were also reduced. DNA sequencing revealed that the propositus has carried compound heterozygous mutations (Lys341Glu and IVS6-1G>A) of the F7 gene. Her father and younger sister were heterozygous for the IVS6-1G>A mutation, while her mother and daughter were heterozygous for the Lys341Glu mutation. Bioinformatics analysis indicated that Lys341Glu mutation may affect the stability and function of the FⅦ protein.@*Conclusion@#The Lys341Glu and IVS6-1G>A mutations probably underlie the reduced activity of FⅦ in this pedigree.

Epidemiological characteristics and short-term epidemiological trend prediction of human brucellosis in Baotou City, Inner Mongolia, 2003-2017 / 中华地方病学杂志

Objective To analyze the epidemiological characteristics of human brucellosis in Baotou City,Inner Mongolia in 2003-2017,conduct short-term forecasting of incidence of brucellosis in 2018-2020,and provide evidence for early warning and scientific prevention of brucellosis.Methods The epidemic data of human brucellosis in Baotou City from 2003 to 2017 came from the Infectious Disease Monitoring Information System of China Disease Prevention and Control Information System,and the demographic data came from the statistical yearbook of Baotou City.Descriptive epidemiological method was used to analyze the prevalence,time distribution,regional distribution,and population distribution of brucellosis.According to the monthly incidence of human brucellosis in 2003-2017,autoregressive integrated moving average (ARIMA) model was established using R language,and the ARIMA model was used to predict the incidence of human brucellosis in Baotou City in 2018-2020.Results From 2003 to 2017,there were 5 180 cases of human brucellosis in Baotou City,among them,354 cases in 2016 and 357 cases in 2017.The age of onset was concentrated in 35-64 years old (4 046 cases);the high-incidence areas were pastoral areas (2 218 cases) and rural areas (1 975 cases);the occupational distribution was dominated by farmers (3 930 cases) and herders (552 cases);the peak incidence was from April to July every year.The prediction model of human brucellosis onset in Baotou City was ARIMA (2,1,2) × (1,0,1)12,and the average absolute scale error predicted by the model was 0.585.The constructed ARIMA model predicted that the annual incidence of human brucellosis in Baotou City will be 349,331,and 324 cases in 2018-2020.Conclusions There are seasonal,regional and population distribution characteristics of human brucellosis in Baotou City.Compared with those of 2016 and 2017,the incidences of human brucellosis in Baotou City are relatively stable in 2018-2020,but the possibility of high incidence is not ruled out.We should pay close attention to the trend of epidemic disease,and adopt comprehensive prevention and treatment measures according to epidemiological characteristics,to effectively control human brucellosis.

Identification of compound heterozygous mutations of F11 gene in a pedigree affected with heriditary coagulation factor XI deficiency / 中华医学遗传学杂志

OBJECTIVE@#To identify potential mutations of F11 gene in a pedigree affected with hereditary coagulation factor XI (FXI) deficiency and explore its molecular pathogenesis.@*METHODS@#Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), coagulation factor VIII activity (FVIIIC), coagulation factor IX activity (FIXC), coagulation factor XI activity (FXIC), coagulation factor XII activity (FXIIC) and lupus anticoagulation (LA) of the proband and eight family members were determined. FXI antigen (FXIAg) was determined by enzyme-linked immunosorbent assay (ELISA). For the proband, potential mutations in the exons, flanking introns and 5'-, 3'-untranslated regions of the F11 gene were screened by direct DNA sequencing. The results were confirmed by reverse sequencing. Suspected mutations were detected in other family members. ClustalX-2.1-win and four online bioinformatic tools (PolyPhen-2, PROVEAN, SIFT, and Mutation Taster) were used to study the conservation and possible impact of the mutations. The structure of the mutational sites was processed with Swiss-PdbViewer.@*RESULTS@#The propositus had prolonged APTT (69.6 s), whose FXIC and FXIAg were reduced to 6.0% and 10.7%, respectively. Her mother, elder sister, one younger sister, little brother, daughter and son showed slightly prolonged APTT and moderate FXIC and FXIAg levels. Gene sequencing revealed that the propositus carried a heterozygous nonsense mutation c.738G>A (p.Trp228stop) in exon 7 and a heterozygous mutation c.1556G>C (p.Trp501Ser) in exon 13. Her mother, elder sister and daughter were heterozygous for the p.Trp228stop mutation, while one younger sister and little brother and son were heterozygous for p.Trp501Ser. Her husband and the youngest sister were of the wild type. Phylogenetic analysis suggested that Trp501 was highly conserved among all homologous species. The p.Trp501Ser was predicted to be "probably damaging","deleterious", "affect protein function" and "disease causing" corresponding to PolyPhen-2, PROVEAN, SIFT and Mutation Taster. Model analysis demonstrated that the non-polar Trp501 has two benzene rings, forming a hydrogen bond with Gln512 in the wild type. Once substituted by Ser501, the side chain may form another hydrogen bond with the benzene of His396. This may affect the normal space conformation and stability of FXI protein.@*CONCLUSION@#The compound heterozygous mutations of the F11 gene probably accounted for the low FXI concentration in this pedigree.

Genetic analysis and clinical features of a pedigree affected with hereditary coagulation factor Ⅶ deficiency caused by compound heterozygotic mutations / 中华医学遗传学杂志

OBJECTIVE@#To detect potential mutations of the coagulation factor Ⅶ (F7) gene in a pedigree affected with hereditary FⅦ deficiency and explore its molecular pathogenesis.@*METHODS@#The FⅦ antigen (FⅦ:Ag) was analyzed by an enzyme-linked immunosorbent assay (ELISA) method. Prothrombin time (PT), FⅦ activity (FⅦ:C) and other coagulant parameters were quantified with an one-stage clotting assay. The F7 gene was amplified by PCR and sequenced. Mutational sites were confirmed by reverse sequencing. Impact of amino acid substitution was assessed using SIFT and PolyPhen-2 software. Structure of the mutant protein was analyzed using Swiss-pdb Viewer software based on the three-dimensional structure in the Protein Data Bank.@*RESULTS@#The propositus had prolonged PT (36.3 s), with FⅦ:C and FⅦ:Ag significantly reduced to 2% and 44%, respectively. Her father, mother, younger sister and daughter had slightly prolonged PT and reduced FⅦ:C (86%-120%). The FⅦ:Ag of her father and younger sister were also reduced. DNA sequencing revealed that the propositus has carried compound heterozygous mutations (Lys341Glu and IVS6-1G>A) of the F7 gene. Her father and younger sister were heterozygous for the IVS6-1G>A mutation, while her mother and daughter were heterozygous for the Lys341Glu mutation. Bioinformatics analysis indicated that Lys341Glu mutation may affect the stability and function of the FⅦ protein.@*CONCLUSION@#The Lys341Glu and IVS6-1G>A mutations probably underlie the reduced activity of FⅦ in this pedigree.

Phenotypic and genetic analysis of a pedigree affected with hereditary FV deficiency due to a novel deletional variant of F5 gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the phenotype and F5 gene variant in a pedigree affected with hereditary coagulation factor V (FV) deficiency.@*METHODS@#All of the exons, flanking sequences, and 5' and 3' untranslated regions of the F5 gene were subjected to PCR and direct sequencing. Suspected variant sites were confirmed by clone sequencing. Influence of the variants was predicted by using software including ClustalX and Mutation Taster.@*RESULTS@#The prothrombin time (PT) and activated partial thromboplastin time (APTT) of the proband were prolonged to 20.3 s and 59.2 s, respectively, while FV activity (FV:C) and FV antigen (FV:Ag) were reduced by 13% and 17%, respectively. The FV:C and FV:Ag of his father, sister and daughter were decreased to 35%, 37%, 29% and 42%, 46%, 35%, respectively. The proband was found to carry a heterozygous c.2851delT variant in exon 13 of the F5 gene, which caused a frameshift and resulted in a truncated protein (p.Ser923LeufsX8). In addition, a heterozygous c.1538G to A (p.Arg485Lys) variant was found in exon 10. The father, sister and daughter of the proband all carried the p.Ser923LeufsX8 variant, while his mother and son carried the heterozygous p.Arg485Lys polymorphism. His younger brother and wife were of the wild type. Bioinformatic analysis showed that p.Ser923 was highly conserved across various species. Mutation Taster scored 1.00 for the p.Ser923LeufsX8 variant, and the result has predicted a corresponding disease.@*CONCLUSION@#A heterozygous deletional mutation c.2851delT in exon 13 of the F5 gene and a heterozygous c.1538G to A polymorphism harbored by the proband may be associated with the decreased FV level in this pedigree.

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)

Phenotypic and mutational analysis of a pedigree affected with hereditary coagulation factor Ⅴ deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular pathogenesis for a pedigree affected with coagulation factor Ⅴ (FⅤ) deficiency.</p><p><b>METHODS</b>Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), coagulation factor Ⅱ activity (FⅡ: C), FⅤ activity (FⅤ: C), coagulation factor Ⅶ activity (FⅦ: C), and coagulation factor Ⅹ activity (FⅩ: C) were determined with a STAGO automatic coagulometer. FⅤ antigen (FⅤ: Ag) was detected with enzyme linked immunosorbent assay (ELISA). All exons and their flanking regions, and 5' and 3' untranslated regions of the F5 gene were analyzed by direct sequencing. Suspected mutation was verified by reverse sequencing as well as testing of family members. ClustalX software was used to analyze the conservative property of the mutation sites. PROVEAN and MutationTaster online software was used to predict the effect of the mutation on the protein function. Swiss-pdbViewer was used to analyze the protein model and interaction of amino acids.</p><p><b>RESULTS</b>The PT and APTT of the proband were slightly prolonged to 15.2 s and 41.8 s, respectively. And the FⅤ: C and FⅤ: Ag measured 55% and 62%, respectively. The FⅤ: C and FⅤ: Ag of his father and son were decreased to various extent (60%, 65% and 31%, 40%, respectively). A c.911G>A heterozygous mutation (Gly276Glu) was detected in exon 6 of the proband, for which her father and son were heterozygotes. The same mutation was not found in her mother, brother and husband. Conservation analysis showed that the Gly276 is highly conserved across various species. By bioinformatic analysis, the PROVEAN (scored -6.214) indicated Gly276Glu was harmful, and MutationTaster (scored 0.976) suggested that it is pathogenic. Model analysis suggested there are two hydrogen bonds between Gly276 and Ile298 in the wild type protein. When Gly276 was replaced by Glu276, the original hydrogen bond did not change, but the side chain of Glu was extended, which added steric hindrance with the surrounding amino acids, which resulted in decreased protein stability.</p><p><b>CONCLUSION</b>The heterozygous c.911G>A (Gly276Glu) mutation of the F5 gene probably underlies the decreased level of FⅤin the proband.</p>

Analysis of a consanguineous pedigree affected with hereditary coagulation factor XII deficiency caused by homozygous Gly341Arg mutation / 中华医学遗传学杂志

OBJECTIVE To analyze the laboratory phenotype and FXII gene mutation in a consanguineous Chinese pedigree affected with factor XII (FXII) deficiency. METHODS Activated partial thromboplastin time (APTT), FXII activity (FXII:C) and FXII antigen (FXII:Ag) of the proband and her family members (10 individuals from 3 generations) were determined. Sanger sequencing was used to detect potential mutation within the 14 exons, their flanking regions and 5',3'-untranslated regions of the FXII gene. Suspected mutations were verified by backward sequencing. Conservation of the amino acids were analyzed with ClustalX-2.1-win. Four online bioinformatics software (PolyPhen-2, PROVEAN, SIFT and MutationTaster) were used to assess the impact of the mutations on the protein function. RESULTS The APTT of the proband and her elder brother have prolonged to 61.6 s and 68.6 s,and their FXII:C and FXII:Ag have decreased to 12%, 10% and 11%, 10%, respectively. The APTT of the paternal grandmother, maternal grandmother, father, mother, elder paternal aunt and elder maternal aunt were all normal, but their FXII:C and FXII:Ag have reduced to half of the normal value. Gene sequencing found that the proband and her elder brother have both carried a homozygous missense c.1078G>A (p.Gly341Arg) mutation in exon 10 of the FXII gene, for which the paternal grandmother, maternal grandmother, father, mother, elder paternal aunt and elder maternal aunt were heterozygous. Bioinformatic analysis suggested that the Gly341 is highly conserved, while p.Gly341Arg is a harmful mutation which may cause disease by affecting the function of FXII protein. CONCLUSION Homozygous p.Gly341Arg mutation, caused by consanguineous marriage, probably underlies the congenital FXII deficiency in this pedigree.

Analysis of phenotypes and genetic mutations in two pedigrees affected with hereditary protein C deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the pathogenesis of protein C deficiency in two pedigrees through mutation detection and model analysis.</p><p><b>METHODS</b>Chromogenic substrate method and enzyme linked immunosorbent assay (ELISA) were used to determine the plasma protein C activity (PC: A) and protein C antigen (PC: Ag) in the two probands and their family members. All of the 9 exons and intron-exon boundaries of the PROC gene were amplified by PCR and analyzed with Sanger sequencing after purification. Corresponding mutate sites of the family members were also amplified and sequenced. The PolyPhen-2 software was used to analyze the perniciousness of the mutations and Clustal X was to analyze the conservatism. The protein model and amino acids interaction of the mutations were analyzed by Swiss-PdbViewer software.</p><p><b>RESULTS</b>The PC: A and PC: Ag of proband 1 was 30% and 35%, while PC:A of his father, mother and aunt were all slightly under the reference range. Two heterozygous missense mutations were found in exons 7 and 5 of the PROC gene, namely c.565 C>T (p.Arg147Trp) and c.383 G>A (p.Gly86Asp). His father and aunt were carriers for c.565 C>T, while his mother had carried c.383 G>A. The PC: A of proband 2 and his son were 50% and 64%, respectively. And they were both positive for p.Arg147Trp. Analysis of PolyPhen-2 indicated that p.Arg147Trp was benign, while p.Gly86Asp was damaging. Clustal X analysis indicated that the p.Arg147Trp was non-conservative, while the p.Gly86Asp was highly conservative. Modeling for the mutant proteins revealed that the simple aromatic ring of Trp147 in p.Arg147Trp destroyed the two hydrogen bonds between Arg147-Lys146 and Arg147-Lys151, and steric hindranted with Arg178. The side chain of Asp86 extended and generated steric clash with Gln90 with the occurrence of p.Gly86Asp. The change of hydrogen bonds and steric effects has altered the spatial configuration of amino acids, which led to unstable mutate proteins and interfered with the secretion.</p><p><b>CONCLUSION</b>Both probands had hereditary protein C deficiencies, for which their parents were all carriers. The heterozygous mutations p.Arg147Trp and p.Gly86Asp were the main cause for PC: A activity decrease. Among these, p.Gly86Asp was discovered for the first time.</p>

Phenotypic and genetic analysis of two pedigrees affected with hereditary antithrombin deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the phenotype, genotype and molecular mechanism for two pedigrees affected with hereditary antithrombin (AT) deficiency.</p><p><b>METHODS</b>Clinical diagnosis was validated by assaying of coagulation parameters including prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, antithrombin activity (AT:A) and specific antigen (AT:Ag), protein C activity, as well as protein S activity. To detect potential mutations in the probands, all exons, exon-intron boundaries and the 3', 5' untranslated regions were amplified by PCR and subjected to direct sequencing. Suspected mutation was confirmed by reverse sequencing and silver staining. The effect of mutations on the AT protein was analyzed with bioinformatics software.</p><p><b>RESULTS</b>The AT:Ag of pedigree 1 was normal, but its AT:A has reduced to 30%. A heterozygous c.235C>T mutation in exon 2 causing p.Arg47Cys, in addition with two single nucleotide polymorphisms (c.981G>A, c.1011G>A) in exon 5 were identified in the patient. His four children, except for the elder daughter, were heterozygous for the mutations. The plasma levels of AT:A and AT:Ag in proband 2 have decreased to 39% and 103 mg/L, respectively. A heterozygous deletion (g.5890-5892delCTT) leading to loss of p.Phe121 was also detected in his father. Bioinformatic analysis suggested that the missense mutation Arg47Cys can affect the functions of AT protein. Meanwhile, lacking of Phe121 will result in loss of hydrogen bonds with Ala124, Lys125 and the cation π interactions with Lys125, Arg47, which may jepordize the stability of the protein.</p><p><b>CONCLUSION</b>The proband 1 had type II AT deficiency, while proband 2 had type I AT deficiency. The p.Arg47Cys and g.5890-5892delCTT mutations of the AT gene are significantly correlated with the levels of AT in the two probands, respectively.</p>

Homozygous missense mutation p.Val298Met of F10 gene causing hereditary coagulation factor X deficiency in a Chinese pedigree / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation underlying coagulation factor X (FX) deficiency in a consanguineous Chinese pedigree.</p><p><b>METHODS</b>Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, FX activity (FX:C) and other coagulant parameters were determined with a one-stage clotting assay. The FX antigen (FX:Ag) was determined with an ELISA assay. All coding exons and exon-intron boundaries of the F10 gene were amplified with PCR and subjected to direct sequencing. Suspected mutation was confirmed by reverse sequencing and analyzed with CLC Genomics Workbench 7.5 software.</p><p><b>RESULTS</b>The PT and APTT in the proband were prolonged to 67.2 s and 102.9 s, respectively. Further study showed that her FX:C and FX:Ag were reduced by 1% and 8%, respectively. The PT of her father, mother, and little brother were slightly prolonged to 14.5 s, 14.4 s and 14.4 s, respectively. The FX:C and FX:Ag in her father, mother and little brother were all slightly reduced. Genetic analysis of the proband has revealed a homozygous G>A change at nucleotide 27881 in exon 8 of the F10 gene, which predicted a p.Val298Met substitution. The proband's father, mother, and little brother were all heterozygous for the p.Val298Met mutation. The proband has inherited the homozygous mutation from her parents by consanguineous marriage. Other family members were all normal. Bioinformatics analysis has indicated that this mutation may result in changes in the secondary structure of the FX protein.</p><p><b>CONCLUSION</b>A homozygous mutation g.27881G>A(p.Val298Met) of the F10 gene has been identified, which probably accounts for the low FX concentrations in this pedigree.</p>