Objective:Molecular mechanisms underlying compound heterozygous mutations in a patient with inherited antithrombin (AT) deficiency.Methods:The proband was admitted to the First Affiliated Hospital of Wenzhou Medical University in November 2018 with a one-day history of sudden syncope and limb twitching. Peripheral venous blood was collected from the proband and members of his lineages, totaling nine persons across three generations, and a family lineage survey was conducted. AT activity (AT:A) was measured using a chromogenic substrate assay, while AT antigen (AT:Ag) was detected through an immunoturbidimetric assay. Mutation sites were identified by means of Sanger sequencing of the SERPINC1 gene, and silico tools were applied to predict the mutational conservation and hydrophobicity changes. Recombinant plasmid expression vectors were constructed and transfected into HEK293T cells for in vitro overexpression studies. The recombinant AT protein was characterized using Western Blotting, ELISA, and cellular immunofluorescence assays.Results:The proband was a 21-year-old man with type Ⅰ AT deficiency. His AT:A was 33%, along with a corresponding reduction in AT:Ag. The genetic analysis revealed there was a heterozygous insertion mutation at c.318_319insT (p.Asn107*) and a heterozygous missense mutation at c.922G>T (p.Gly308Cys) in exons 2 and 5, respectively. These mutation sites were entirely conserved among the homologous species. Additionally, hydrophobicity studies showed that the p.Gly308Cys mutation will decrease the hydrophilicity of amino acid residues 307-313. The in vitro expression studies indicated a reduction of approximately 46.98%±2.94% and 41.35%±1.48% in the amount of recombinant protein AT-G308C in transfected cell lysates and culture supernatants, respectively. Treatment with the proteasome inhibitor (MG132) restored the cytoplasmic levels of AT-G308C protein to a level similar to that of wild-type protein. However, neither cell lysate nor culture supernatant demonstrated the presence of the recombinant protein AT-N107*. Conclusions:The heterozygous insertion mutation of p.Asn107* and the heterozygous missense mutation of p.Gly308Cys have been associated with reduced AT levels in proband. The p.Asn107* heterozygous insertion mutation may initiate the degradation of mRNA via nonsense mutation-mediated mechanisms, which would remove the defective transcripts, as well as the p.The Gly308Cys heterozygous missense mutation may cause the AT protein to undergo proteasome-dependent degradation by modifying the hydrophobicity of nearby residues in the cytoplasm.

Objective:To investigate the relationship between inherited protein S deficiency (PSD) and cerebral venous sinus thrombosis (CVST) by phenotype and gene mutation analysis of 2 inherited PSD pedigrees with nonsense mutations.Methods:Retrospective analysis of clinical and imaging data of 2 patients diagnosed with CVST who were treated in the Department of Neurology, the First Affiliated Hospital of Wenzhou Medical University in July and October 2023 was carried out. The peripheral blood samples were collected from proband 1 and her family members (3 subjects, 2 generations in total), and proband 2 and his family members (8 subjects of 3 generations in total). Their protein S (PS) activity (PS:A), the content of total PS antigen (TPS:Ag) and free PS antigen (FPS:Ag) were measured for definite diagnosis. Polymerase chain reaction was done in all 15 exons of the active PROS1 gene and its 5′ and 3′ untranslated regions and the amplification products were analyzed by direct sequencing. The results were compared with human PROS1 reference sequences, using Chromas software to find the mutation sites. Results:The proband 1 is a female, and the proband 2 is a male. Both of them had young onset and the clinical presentation of CVST. The PS:A level was reduced to 29% in the proband 1 and reduced to about 35% in her mother; PS:A was reduced to 21%-27% in the proband 2 and his 6 family members; a decline in the same proportion of TPS:Ag and FPS:Ag was found in the 2 probands and their family members, therefore they were primarily diagnosed as typeⅠPSD. Gene analysis showed that the proband 1 and her mother had a nonsense mutation of c.1680T>A in exon 14 (p.Tyr560 *) of the PROS1 gene; the proband 2 and his 6 family members had a nonsense mutation of c.1687C>T in exon 14 (p.Gln563 *) of the PROS1 gene. Conclusion:The reduced protein S levels in PSD patients and their family members may be associated with the p.Tyr560 * and p.Gln563 * nonsense mutations of the PROS1 gene, and the clinical manifestations of CVST in PSD patients may be related to these 2 nonsense mutations.

Objective:To analyze 12 antithrombins (AT) gene mutations that cause AT deficiency and discuss the relationship between the SERPINC1 gene. mutations and venous thrombotic events.Methods:This study belongs to case series of observational studies. Collected the clinical data of 12 AT deficiency cases in the First Affiliated Hospital of Wenzhou Medical University from April 2014 to April 2021 and collected the blood samples before treatment. The AT activity (AT: A) and AT antigen (AT: Ag) was detected by chromogenic substrate and immunoturbidimetry, respectively. The 7 exons and flanking sequences of the SERPINC1 gene were sequenced directly by PCR, the suspected mutations were validated by reverse sequencing. Analyzed the correlation between the SERPINC1 gene. mutations and venous thrombotic events and figured out the proportion.Results:The AT: A of the 12 patients all decreased significantly, ranging from 30% to 66%, and the AT: Ag of the 7 patients decreased accordingly, showing type Ⅰ AT deficiency, and the AT: Ag of the other 5 patients were normal, presented type Ⅱ AT deficiency. 12 mutations were found including 6 heterozygous mutations which were discovered for the first time: c.456_458delCTT(p.phe121del), c.318_319insT(p.Asn75stop), c.922G>T(p.Gly276Cys), c.938T>C (p.Met281Thr), c.1346T>A(p.Leu417Gln)and c.851T>C(p.Met252Thr). All 12 patients had venous thrombosis, and 3 cases including 2 compound heterozygotes and 1 single heterozygote all suffered from deep venous thrombosis (DVT) when they were younger without obvious triggers. The other 9 patients all combined with the other thrombotic factors including old age, hypertensive, smoking, pregnancy, and prolonged immobilization.Conclusion:Patients with AT deficiency caused by SERPINC1 gene defects are prone to venous thrombosis, especially combined with other thrombotic factors.

Objective:To explore the molecular pathogenesis of hereditary protein C (PC) deficiency due to a p. Gly86Asp variant of the PROC gene through in vitro expression experiment.Methods:Wild type and Gly86Asp mutant expression plasmids of PC were constructed and respectively transfected into HEK 293FT cells. Total RNA was extracted from the transfected cells, and the expression of PROC gene was determined by quantitative real-time PCR (qRT-PCR). PC antigen (PC: Ag) in the supernatant of cell culture and cell lysate was determined by enzyme-linked immunosorbent assay (ELISA), and the level of PC protein was detected by Western blotting. Results:qRT-PCR has detected no significant difference in the transcription level of wild-type and mutant-type PC. Compared with the wild type, the level of mutant PC: Ag in the supernatant and cell lysate were 81.3%±2.6% and 110.0%±2.8%, respectively. No difference was detected in the molecular weight between the wild-type and mutant-type PC by Western blotting. The PC content of mutant type was higher than wild-type in cell lysate, while the opposite was found with the cell culture supernatant.Conclusion:The impaired secretion by mutant PC may be the molecular mechanism of PC deficiency caused by the p.

Objective:To explore the genetic basis for a patient with factor XIII (FXIII) deficiency.Methods:All exons of the F13A1 and F13B genes were amplified by PCR and sequenced directly. The sequencing was performed with a reverse primer if a variant was found. Conservation of variant site was analyzed by the ClustalX software. Four online bioinformatic software including MutationTaster, PolyPhen-2, PROVEAN and SIFT were used to predict the function of the mutation site. The Swiss-PdbViewer software was applied to analyze the changes in the protein model and intermolecular force. Results:The proband was found to harbor a novel c. 515G>C (p.Arg171Pro) variant of the F13A1 gene. The corresponding amino acid Arg171 is conserved among homologous species. Bioinformatic analysis indicated that Arg171Pro variant may affect the protein function. Protein model analysis showed that in the wild-type, there is one hydrogen bond between Arg171 and Pro27; one hydrogen bond between Arg171 and Thr28; two hydrogen bonds between Arg171 and Glu102. When Arg171 was mutated to Pro171, the three hydrogen bonds between Arg171 and Pro27, Glu102 are all disappeared and formed a new benzene ring which might affect the stability of the protein structure. No variant was found in the F13B gene. Conclusion:The Arg171Pro variant may account for the decreased FXIII level. Above finding has enriched the spectrum of F13A1 gene variants.

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.

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.
Exons ; Factor XII ; genetics ; Factor XII Deficiency ; genetics ; Heterozygote ; Humans ; Pedigree

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.

OBJECTIVETo identify potential mutation underlying coagulation factor X (FX) deficiency in a consanguineous Chinese pedigree.

METHODSProthrombin 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.

RESULTSThe 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.

CONCLUSIONA 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.

Adult ; Amino Acid Sequence ; Consanguinity ; Factor X ; genetics ; Factor X Deficiency ; genetics ; Female ; Homozygote ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Mutation, Missense ; Pedigree ; Prothrombin Time

OBJECTIVETo investigate the polymorphism in the promoter region of PCA3 gene and its relationship with risk of prostate cancer (PCa).

METHODSThe promoter region of PCA3 gene of the DNA of peripheral blood mononuclear cells was detected by sequence analysis in the 186 PCa and 141 BPH patients and 135 healthy control individuals. If the samples were detected with polymorphism of insection/deletion, clone sequence analysis was used with pBS-T carrier to verify it.

RESULTSThere were 5 polymorphisms. TAAA repeat times: 4, 5, 6, 7, 8, and 8 genotypes (TAAA 4/5, TAAA 4/6, TAAA 5/5, TAAA 5/6, TAAA 5/7, TAAA 5/8, TAAA 6/6, and TAAA 6/7) were detected in the promoter region of PCA3 gene. The eight genotypes were divided into three groups: ≤10TAAA, 11TAAA, ≥12TAAA. Unconditional logistic regression analysis models were used to analyze the relationship between different genotypes and cancer risks adjusted by sex and age. The type 11TAAA and ≥12TAAA was associated with higher relative risk for prostate cancer than the group ≤10TAAA [OR=1.74, 95% CI=1.06-2.87 (for type 11TAAA); OR=5.63, 95% CI=1.85-17.19 (for type ≥12TAAA)]. In the 186 PCa patients, there was 62.4% allele of PCA3 gene with AG/CA mutation found in the promoter 18-19 bp region of PCA3 gene and it had a close relation with the development of prostate cancer.

CONCLUSIONSShort tandem repeats are found in the promoter region of the PCA3 gene in PCa patients, and the increase of TAAA repeat sequences highly enhance the relative risk of prostate cancer development. The occurrence of such STR might be related to the mutations in their upstream loci.

Antigens, Neoplasm ; genetics ; metabolism ; Base Sequence ; Genes, Neoplasm ; physiology ; Genotype ; Humans ; Leukocytes, Mononuclear ; Male ; Microsatellite Repeats ; Mutation ; Polymorphism, Genetic ; Promoter Regions, Genetic ; Prostatic Neoplasms ; epidemiology ; genetics ; Risk