Molecular and clinical characterization of two unrelated families with factor V deficiency, including a novel nonsense variant (p.Gln1532*).

BACKGROUND: Factor V (FV) is an essential cofactor in the coagulation cascade. The characterization of novel mutations is advantageous for the clinical management of FV-deficient patients. METHODS: Coagulation screening and thrombin generation assay were performed with the plate-poor plasma. All 25 exons of the F5 gene were amplified and sequenced. The ClustalX-2.1 software was applied to the multiple sequence alignment. The possible adverse effects of mutations were investigated with online bioinformatics software and protein modeling. RESULTS: Two unrelated families with FV deficiency were under investigation. Proband A was an 18-year-old youth with recurrent epistaxis. Proband B was a 29-year-old woman who did not present with any bleeding symptoms. Three heterozygous mutations (p.Gln1532*, p.Phe218Ser, and p.Asp2222Gly) were detected. Interestingly, they were compound heterozygotes and both contained the p.Asp2222Gly, a polymorphism. The thrombin generation assay showed that both patients had impaired ability of thrombin generation, and in particular, proband A was more severe. Conservation, pathogenicity and protein modeling studies all indicated that these three mutations could cause deleterious effects on the function and structure of FV. CONCLUSION: These three mutations are responsible for the FV-deficient in two pedigrees. Moreover, the nonsense variant p.Gln1532* is first reported in the world.

Analysis of PROS1 mutations and clinical characteristics in three Chinese families with hereditary protein S deficiency.

We report three heterozygous PROS1 mutations that caused type I protein S deficiency in three unrelated Chinese families. We measured protein S activity and antigen levels for all participants, screened them for mutations in the PROS1 gene. And we employed the calibrated automated thrombin generation (CAT) method to investigate thrombin generation. Numerous bioinformatics tools were utilized to analyze the conservation, pathogenicity of mutation, and spatial structure of the protein S. Phenotyping analysis indicated that all three probands exhibited simultaneous reduced levels of PS:A, TPS:Ag, and FPS:Ag. Genetic testing revealed that proband A harbored a heterozygous c.458_458delA (p.Lys153Serfs*6) mutation in exon 5, proband B carried a heterozygous c.1687C>T (p.Gln563stop) mutation in exon 14, and proband C exhibited a heterozygous c.200A>C (p.Glu67Ala) mutation in exon 2. Bioinformatic analysis predicted that the p.Lys153Serfs*6 frameshift mutation and the p.Gln563stop nonsense mutation in the protein S were classified as "disease-causing." The identification of the novel mutation p.Lys153Serfs*6 in PROS1 enriches the Human Genome Database. Our research suggests that these three mutations (p.Lys153Serfs*6, p.Gln563stop, and p.Glu67Ala) are possibly responsible for the decreased level of protein S in the three families. Furthermore, the evidence also supports the notion that individuals who are asymptomatic but have a family history of PSD can benefit from genetic analysis of the PROS1 gene.

Analysis of PROC mutations and clinical features in 22 unrelated families with inherited protein C deficiency.

Currently, limited information is available in the literature regarding the relationships between PROC mutations and clinical features in Chinese individuals. We aimed to characterize severe congenital Protein C deficiency in 22 unrelated Chinese families in a tertiary hospital by analyzing its clinical manifestation, associated risk factors, and gene mutations. We measured protein C activity and antigen levels for all participants, screened them for mutations in the PROC gene, and analyzed the clinical features of each family to identify commonalities and differences. The analysis revealed a total of 75 individuals with PCD and 16 different PROC mutations, including 12 missense mutations and 4 deletion mutations. Among them, 11 who were compound heterozygotes or homozygotes for mutations tended to develop symptoms at a younger age without any clear triggers. In contrast, the remaining 64 individuals who were heterozygotes for mutations often had clear triggers for their symptoms and experienced a milder course of the disease. It is worth noting that the mutation c.565C > T occurred most frequently, being identified in 8 out of 22 families (36%). Our team also reported five novel mutations, including c.742-744delAAG, c.383G > A, c.997G > A, c.1318C > T, and c.833T > C mutations. The identification of five novel mutations adds to the richness of the Human Genome Database. Asymptomatic heterozygotes are not uncommon, and they are prone to develop symptoms with obvious triggers. The evidence presented strongly suggest that asymptomatic individuals with family history of protein C deficiency can benefit from mutational analysis of PROC gene.

[Analysis of two consanguineous Chinese pedigrees affected with Hereditary prokallikrein deficiency and High molecular weight kininogen deficiency].

OBJECTIVE: To analyze the laboratory phenotype and genetic variants of two consanguineous Chinese pedigrees affected with Hereditary prokallikrein (PK) and High molecular weight kininogen (HMWK) deficiency and explore their molecular pathogenesis. METHODS: A PK deficiency pedigree (10 individuals from 4 generations) and a HMWK deficiency pedigree (6 individuals from 3 generations) which were admitted to the First Affiliated Hospital of Wenzhou Medical University on December 3, 2021 and June 16, 2022, respectively were selected as the study subjects. Clinical data of the two pedigrees were collected, and the related coagulation indexes of the probands and their family members were determined. Genomic DNA of the two pedigrees was extracted from peripheral blood samples. All of the exons and flanking sequences of the KLKB1 and KNG1 genes of the probands were analyzed by direct sequencing. And the corresponding sites were sequenced among other family members. Bioinformatic software was used to analyze the conservation of variation sites and the effect of variant on the protein function. RESULTS: The plasma PK activity of proband 1, a 29-year-old female, and her brother were extremely low (< 1.0%). Proband 2 was a 66-year-old male with extremely low plasma HMWK activity (< 1.0%). Genetic sequencing revealed that the proband 1 and her brother had both harbored a homozygous c.417_418insCATTCTTA (p.Arg140Hisfs*3) insertional variant in exon 5 of the KLKB1 gene. Proband 2 had harbored a homozygous c.460C>A (p.Pro154Thr) missense variant in exon 4 of the KNG1 gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variants were respectively rated as pathogenic (PVS1+PM2_Supporting+PM4) and likely pathogenic (PS4+PM2_Supporting+PP3+PP4). CONCLUSION: The c.417_418insCATTCTTA (p.Arg140Hisfs*3) variant of the KLKB1 gene and the c.460C>A (p.Pro154Thr) variant of the KNG1 gene probably underlay the decreased PK and HMWK activities in the two pedigrees, respectively.

[Analysis of three Chinese pedigrees affected with Hereditary factor â ¦ deficiency due to compound heterozygous variants of F7 gene].

OBJECTIVE: To analyze the types of genetic variants and clinical characteristics of three Chinese pedigrees affected with Hereditary coagulation factor Ⅶ (FⅦ) deficiency. METHODS: Three pedigrees who had visited the First Affiliated Hospital of Wenzhou Medical University between December 2021 and October 2022 were selected as the study subjects. Prothrombin time (PT), activated partial thromboplastin time (APTT) and FⅦ activity (FⅦ:C) were measured in the three probands and their pedigree members. All exons and their flanking sequences were analyzed by direct sequencing, and candidate variants were verified by reverse sequencing. The corresponding variant loci in the family members were also analyzed. ClustalX-2.1-win was used to analyze the conservation of the variant loci. Varcards and Spcards online software was used to predict the pathogenicity of the variants. Pymol software was used to analyze the changes in protein structure and molecular forces. RESULTS: Three cases of hereditary FⅦ deficiency were found to have decreased FⅦ:C, prolonged PT and normal APTT. Genetic analysis identified a total of four genetic variants, and all three probands had harbored compound heterozygous variants of the F7 gene, including p.Cys389Gly and p.His408Gln in proband 1, p.Cys389Gly and IVS6+1G>T in proband 2, and IVS6+1G>T and IVS1a+5G>A in proband 3. Conservation analysis showed that both the p.Cys389 and p.His408 loci are highly conserved among orthologous species. Analysis with Varcards and Spcards software showed that these variants were pathogenic. Protein modeling analysis showed that the p.Cys389Gly and p.His408Gln variants may result in altered protein structures and changes in hydrogen bonds. CONCLUSION: The clinical manifestations of the three FⅦ-deficient probands may be attributed to the compound heterozygous variants of p.Cys389Gly/p.His408Gln, p.Cys389Gly/IVS6+1G>T and IVS6+1G>T/IVS1a+5G>A of the F7 gene. The combination of the three compound heterozygous variants was unreported previously.

Gene Variants in Two Families with Inherited Coagulation Factor XI Deficiency and Identification of Mutations.

INTRODUCTION: Mutations in the F11 gene can cause factor XI (FXI) deficiency, leading to abnormal coagulation activity and injury-related bleeding tendency. Therefore, identifying F11 gene mutations and studying the molecular basis will help us understand the pathogenesis of FXI deficiency. METHODS: Coagulation tests and gene sequencing analysis of all members were performed. FXI wild-type and mutant expression plasmids were constructed and transfected into HEK293FT cells. The FXI protein expression level was evaluated by ELISA and Western blot. RESULTS: The FXI activity (FXI:C) and FXI antigen (FXI:Ag) of proband-1 were decreased to 2% and 5%, respectively. FXI:C and FXI:Ag of proband-2 were reduced to 15% and 32%, respectively. Four mutations were found in the two unrelated families, including c.536C>T (p.T179M), c.1556G>A (p.W519*), c.434A>G (p.H145R), and c.1325_1325delT (p.L442Cfs*8). In vitro studies in transiently transfected HEK293FT cells demonstrated that p.T179M, p.W519*, and p.L442Cfs*8 mutations significantly lowered the FXI levels in the culture media. The FXI levels in the culture media and cell lysates of p.H145R mutation were similar to the wild type. CONCLUSION: Our results confirm that the four mutations in the F11 gene are causative in the 2 FXI deficiency families. Moreover, the p.H145R mutation is a cross-reactive material (CRM)-positive phenotype. The other three mutations are CRM-negative phenotypes and lead to FXI protein secretion disorder.

Preeclampsia complicated with hypofibrinogenemia: 2 case reports and review of the literature.

BACKGROUND: Preeclampsia complicated with hypofibrinogenemia is a rare disorder. We report two cases of severe preeclampsia complicated with hypofibrinogenemia followed by postpartum haemorrhage (PPH). CASE: Two women diagnosed as preeclampsia and hypofibrinogenemia developed severe PPH after undergoing Cesarean sections. Besides supplement with fibrinogen concentrate and supportive treatment, the second patient got administration of heparin after delivery and bleeding was stopped. The haemorrhage in case 1 didn't disappear until an hysterectomy. The two patients both recovered and were discharged soon. CONCLUSIONS: Severe preeclampsia patients with hypofibrinogenemia could suffer PPH. It's necessary to detect and master coagulation function. Heparin could be considered to balance hypercoagulation and hypocoagulation to avoid catastrophic haemorrhage and hysterectomy.

The effects of short-term exposure to air pollution on mortality in Baotou, China, during 2015-2019.

Air pollution was considered one of the main causes linked to increased morbidity and mortality around the world. This study aimed to estimate the effect of air pollutants on daily death in Baotou city of Inner Mongolia. Daily deaths data were provided by Baotou Centers for Disease Control and Prevention for the years 2015-2019 (Baotou CDC). The air pollutants, PM2.5, PM10, NO2, SO2, CO and maximum 8-h average concentrations of O3, came from the eight environmental monitoring stations in Baotou city. Time-series plots were used to exploit the trend of air pollutants at calendar time. Generalized additive model was used to estimate the effect of air pollutants on daily death. Restricted cubic spline was employed to investigate non-line relationships between air pollutants and daily death. After adjusting the meteorological factors, non-accidental daily deaths were related to PM2.5 (ER = 0.074%) and PM10 (ER = 0.023%), respectively. In stratified analysis, population aged over 65 years and females were more sensitive to air pollutants exposure and warm season might make people more susceptible to air pollutants compared with cold season. PM2.5 and PM10 increase the risk of non-accidental and cardiovascular daily death, but not respiratory daily death.

[Analysis of a Chinese pedigree affected with Hereditary coagulation factor â ª deficiency due to variant of F11 gene].

OBJECTIVE: To explore the molecular pathogenesis of a Chinese pedigree affected with Hereditary coagulation factor Ⅺ (FⅪ) deficiency due to variants of the F11 gene. METHODS: A male proband with Hereditary coagulation factor Ⅺ deficiency who was admitted to the First Affiliated Hospital of Wenzhou Medical University due to urinary calculi on November 30, 2020 and his family members (7 individuals from 3 generations in total) were selected as the study subjects. Clinical data of the proband were collected, and relevant coagulation indices of the proband and his family members were determined. Genomic DNA of peripheral blood samples was extracted for PCR amplification. All exons, flanking sequences, and 5' and 3' untranslated regions of the F11 gene of the proband were analyzed by direct sequencing. And the corresponding sites were subjected to sequencing in other family members. The conservation of amino acid variation sites was analyzed by bioinformatic software, and the effect of the variant on the protein function was analyzed. Variants were graded based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: The proband was a 36-year-old male. His activated partial thromboplastin time (APTT) was 89.2s, which was significantly prolonged. The FⅪ activity (FⅪ:C) and FⅪ antigen (FⅪ:Ag) were 2.0% and 3.5%, respectively, which were extremely reduced. Both the proband and his sister were found to harbor compound heterozygous variants of the F11 gene, including a c.689G>T (p.Cys230Phe) missense variant in exon 7 from their father and a c.1556G>A (p.Trp519*) nonsense variant in exon 13 from their mother. Conservation analysis indicated the Cys230 site to be highly conserved. The c.1556G>A (p.Trp519*) variant was known to be pathogenic, whilst the c.689G>T variant was classified as likely pathogenic (PM2+PM5+PP1+PP3+PP4) based on the ACMG guidelines. CONCLUSION: The c.689G>T and c.1556G>A compound heterozygous variants of the F11 gene probably underlay the pathogenesis of FⅪ deficiency in this pedigree.

[Genetic analysis of two Chinese pedigrees affected with Hereditary hypofibrinemia due to missense variants].

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.

Analysis of phenotype and gene mutation in three pedigrees with inherited antithrombin deficiency.

BACKGROUND: Inherited AT deficiency is an autosomal-dominant thrombophilic disorder usually caused by various SERPINC1 defects associated with a high risk of recurrent venous thromboembolism. In this article, the phenotype, gene mutation, and molecular pathogenic mechanisms were determined in three pedigrees with inherited AT deficiency. METHODS: Coagulation indices were examined on STAGO STA-R-MAX analyzer. The AT:Ag was analyzed by ELISA. All exons and flanking sequences of SERPINC1 were amplified by PCR. AT wild type and three mutant expression plasmids were constructed and then transfected into HEK293FT cells. The expression level of AT protein was analyzed by ELISA and Western blot. RESULTS: The AT:A and AT:Ag of probands 1 and 3 were decreased to 49% and 52 mg/dL, 38% and 44 mg/dL, respectively. The AT:A of proband 2 was decreased to 32%. The SERPINC1 gene analysis indicated that there was a p.Ile421Thr in proband 1, a p.Leu417Gln in proband 2, and a p.Met252Thr in proband 3, respectively. The AT mRNA expression level of the three mutants was not significantly different from AT-WT by qRT-PCR. The results of ELISA and Western blot tests showed that the AT-M252T and AT-I421T mutants had a higher AT expression than the AT wild type (AT-WT), and the AT protein expression of AT-L417Q mutants had no significant difference compared with AT-WT in the cell lysate. The AT expression levels of AT-M252T and AT-I421T mutants were lower than that of AT-WT, and there was no significant difference between AT-L417Q mutant and AT-WT in the supernatant. CONCLUSION: The p.I421T and p.M252T mutations affected the secretion of AT protein leading to type I AT deficiency of probands 1 and 3. The p.Leu417Gln mutation was responsible for the impaired or ineffective activity AT protein in proband 2 and caused type II AT deficiency.

[Analysis of the molecular pathogenesis of hereditary protein C deficiency due to a p.Gly86Asp variant of the PROC gene].

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.Gly86Asp variant.

[Analysis of genetic variant in a Chinese pedigree with hereditary factor VIII deficiency].

OBJECTIVE: To explore the genetic basis for a patient with factor VIII 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 Mutation Taster, 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 FVIII level. Above finding has enriched the spectrum of F13A1 gene variants.

Joint Deep Reinforcement Learning and Unsupervised Learning for Channel Selection and Power Control in D2D Networks.

Device-to-device (D2D) technology enables direct communication between devices, which can effectively solve the problem of insufficient spectrum resources in 5G communication technology. Since the channels are shared among multiple D2D user pairs, it may lead to serious interference between D2D user pairs. In order to reduce interference, effectively increase network capacity, and improve wireless spectrum utilization, this paper proposed a distributed resource allocation algorithm with the joint of a deep Q network (DQN) and an unsupervised learning network. Firstly, a DQN algorithm was constructed to solve the channel allocation in the dynamic and unknown environment in a distributed manner. Then, a deep power control neural network with the unsupervised learning strategy was constructed to output an optimized channel power control scheme to maximize the spectrum transmit sum-rate through the corresponding constraint processing. As opposed to traditional centralized approaches that require the collection of instantaneous global network information, the algorithm proposed in this paper used each transmitter as a learning agent to make channel selection and power control through a small amount of state information collected locally. The simulation results showed that the proposed algorithm was more effective in increasing the convergence speed and maximizing the transmit sum-rate than other traditional centralized and distributed algorithms.

Significance of the p.Phe218Ser and p.Gly304Glu F5 Variants in Hereditary Factor V Deficiency.

Hereditary factor V (FV) deficiency is a rare autosomal recessive bleeding disorder caused by F5 gene mutations. The objective of this study was to investigate the p.Phe218Ser and p.Gly304Glu variants found in 2 families with hereditary FV deficiency. The FV activity (FV:C) and FV antigen (FV:Ag) were measured by clotting and ELISA, respectively. The F5 gene and sequence conservation were analyzed by direct sequencing and ClustalX-2.1-win, respectively. One proband carried a homozygous p.Phe218Ser (c.653T>C) mutation, with FV:C and FV:Ag decreased to 11 and 14%, respectively. The other proband carried a heterozygous p.Gly304Glu (c.911G>A) mutation, with FV:C and FV:Ag reduced to 55 and 62%, respectively. Phe218 and Gly304 were highly conserved in the homologous gene in 9 other species. We hypothesized that the p.Phe218Ser and p.Gly304Glu variants are deleterious and responsible for the reduction in FV:C and FV:Ag.

Two Novel Mutations Cause Hereditary Antithrombin Deficiency in a Chinese Family.

OBJECTIVE: To study the molecular basis of hereditary antithrombin (AT) deficiency in a Chinese family. It will help us understand the pathogenesis of this type of disease. METHOD: AT activity (AT:A) and the AT antigen (AT:Ag) level were tested by chromogenic substrate and immunoturbidimetry, respectively. To identify the novel mutations, SERPINC1 gene sequencing was carried out. The possible impact of the mutations was analyzed by model and bioinformatic analyses. RESULTS: AT:A and the AT:Ag level of the proband were 43% and 113 mg/L (normal range: 98-119% and 250-360 mg/L), respectively. Sequencing analysis revealed compound heterozygous mutations, including a frameshift mutation (c.318_319insT) resulting in Asn75stop and a missense mutation (c.922G>T) resulting in Gly276Cys. The bioinformatic and model analyses indicated that these mutations may disrupt the function and structure of the AT protein. CONCLUSION: We detected 2 novel heterozygous mutations (c.318_319insT and c.922G>T) in the proband, and these were associated with decreased AT:A.

[Identification of novel compound heterozygous variants in a pedigree affected with hereditary coagulation factor XI deficiency].

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].

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].

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.

[Phenotypic and genotypic analysis of a pedigree affected with hereditary protein C deficiency due to heterozygous deletional mutation of PROC gene].

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.