rAAV capsid mutants eliminate leaky expression from DNA donor template for homologous recombination.

Precise genomic editing through the combination of CRISPR/Cas systems and recombinant adeno-associated virus (rAAV)-delivered homology directed repair (HDR) donor templates represents a powerful approach. However, the challenge of effectively suppressing leaky transcription from the rAAV vector, a phenomenon associated to cytotoxicity, persists. In this study, we demonstrated substantial promoter activities of various homology arms and inverted terminal repeats (ITR). To address this issue, we identified a novel rAAV variant, Y704T, which not only yields high-vector quantities but also effectively suppresses in cis mRNA transcription driven by a robust promoter. The Y704T variant maintains normal functionality in receptor interaction, intracellular trafficking, nuclear entry, uncoating, and second-strand synthesis, while specifically exhibiting defects in transcription. Importantly, this inhibitory effect is found to be independent of ITR, promoter types, and RNA polymerases. Mechanistic studies unveiled the involvement of Valosin Containing Protein (VCP/p97) in capsid-mediated transcription repression. Remarkably, the Y704T variant delivers HDR donor templates without compromising DNA replication ability and homologous recombination efficiency. In summary, our findings enhance the understanding of capsid-regulated transcription and introduce novel avenues for the application of the rAAV-CRISPR/Cas9 system in human gene therapy.

Rydberg State Single-Mode Polariton Lasing with Ultralow Threshold via Symmetry Engineering.

Symmetry plays an essential role in the fundamental properties of a physical system. In this work, we report on the realization of tunable single-mode polariton lasing from highly excited Rydberg states via symmetry engineering. By breaking the symmetry of the polaritonic wave function through potential wells and controlling the spatial overlap between the gain region and the eigen mode, we are able to generate single-mode polariton lasing, reversibly and dynamically, from quantized polariton states. Increasing the asymmetry of the potential well, single-mode lasing can be achieved even for the highly excited Rydberg state with a principle quantum number of N = 14. Moreover, as a result of the excellent reservoir-eigen mode overlap and efficient spatial confinement, the threshold of lasing can be reduced up to 6 orders of magnitude, compared with those conventional pumping schemes. Our results present a new strategy toward the realization of thresholdless polariton lasing with dynamical tunability.

Relaxation Oscillations of an Exciton-Polariton Condensate Driven by Parametric Scattering.

We report the observation of coherent oscillations in the relaxation dynamics of an exciton-polariton condensate that were driven by parametric scattering processes. As a result of the interbranch scattering scheme and the nonlinear polariton-polariton interactions, such parametric scatterings exhibit a high scattering efficiency that leads to the fast depletion of the polariton condensate and the periodic shut-off of the bosonic stimulation processes, eventually causing relaxation oscillations. Employing polariton-reservoir interactions, the oscillation dynamics in the time domain can be projected onto the energy space. In theory, our simulations using the open-dissipative Gross-Pitaevskii equation are in excellent agreement with experimental observations. Surprisingly, the oscillation patterns, including many excitation pulses, are clearly visible in our time-integrated images, implying the high stability of the relaxation oscillations driven by polariton parametric scatterings.

The role of mRNA in the development, diagnosis, treatment and prognosis of neural tumors.

Neural tumors can generally be divided into central nervous system tumors and peripheral nervous tumors. Because this type of tumor is located in the nerve, even benign tumors are often difficult to remove by surgery. In addition, the majority of neural tumors are malignant, and it is particular the same for the central nervous system tumors. Even treated with the means such as chemotherapy and radiotherapy, they are also difficult to completely cure. In recent years, an increasingly number of studies have focused on the use of mRNA to treat tumors, representing an emerging gene therapy. The use of mRNA can use the expression of some functional proteins for the treatment of genetic disorders or tissue repair, and it can also be applied to immunotherapy through the expression of antigens, antibodies or receptors. Therefore, although these therapies are not fully-fledged enough, they have a broad research prospect. In addition, there are many ways to treat tumors using mRNA vaccines and exosomes carrying mRNA, which have drawn much attention. In this study, we reviewed the current research on the role of mRNA in the development, diagnosis, treatment and prognosis of neural tumors, and examine the future research prospects of mRNA in neural tumors and the opportunities and challenges that will arise in the future application of clinical treatment.

A fecal-based test for the detection of advanced adenoma and colorectal cancer: a case-control and screening cohort study.

BACKGROUND: Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Screening is a confirmed way to reduce the incidence and mortality rates of CRC. This study aimed to identify a fecal-based, noninvasive, and accurate method for detection of colorectal cancer (CRC) and advanced adenoma (AA). METHODS: Through detection in tissue (n = 96) and fecal samples (n = 88) and tested in an independent group of fecal samples (n = 294), the methylated DNA marker ITGA4 and bacterial markers Fusobacterium nucleatum (Fn) and Pepetostreptococcusanaerobius (Pa) were identified from the candidate biomarkers for CRC and AA detection. A prediction score (pd-score) was constructed using the selected markers and fecal immunochemical test (FIT) for distinguishing AA and CRC from healthy subjects by logistic regression method. The diagnostic performance of the pd-score was compared with FIT and validated in the external validation cohort (n = 117) and in a large CRC screening cohort. RESULTS: The pd-score accurately identified AA and CRC from healthy subjects with an area under the curve (AUC) of 0.958, at a specificity of 91.37%; the pd-score showed sensitivities of 95.38% for CRC and 70.83% for AA, respectively. In the external validation cohort, the sensitivities of the pd-score for CRC and AA detection were 94.03% and 80.00%, respectively. When applied in screening, the pd-score identified 100% (11/11) of CRC and 70.83% (17/24) of AA in participants with both colonoscopy results and qualified fecal samples, showing an improvement by 41.19% compared to FIT. CONCLUSIONS: The current study developed a noninvasive and well-validated approach for AA and CRC detection, which could be applied widely as a diagnostic and screening test.

Mechanism for enhanced transduction of hematopoietic cells by recombinant adeno-associated virus serotype 6 vectors.

Hematopoietic gene delivery, such as hematopoietic stem/progenitor cells (HSPCs), is a promising treatment for both inherited and acquired diseases, such as hemophilia. Recently, a combined strategy to achieve more than 90% transduction efficiency was documented using recombinant adeno-associated virus serotype 6 (rAAV6) vectors. However, the mechanisms of enhanced vector transduction efficiency in hematopoietic cells are largely unknown. In this manuscript, we first reported that proteasome inhibitors, which are well-known to facilitate rAAV intracellular trafficking in various cell types, are not effective in hematopoietic cells. From the screening of small molecules derived from traditional Chinese medicine, we demonstrated that shikonin, a potential reactive oxygen species (ROS) generator, significantly increased the in vitro and ex vivo transgene expression mediated by rAAV6 vectors in hematopoietic cells, including human cord blood-derived CD34 + HSPCs. Shikonin mainly targeted vector intracellular trafficking, instead of host cell entry or endonuclear single to double strand vector DNA transition, in a vector serotype-dependent manner. Moreover, a ROS scavenger completely prevented the capability of shikonin to enhance rAAV6 vector-mediated transgene expression. Taken together, these studies expand our understanding of rAAV6-mediated transduction in hematopoietic cells and are informative for improving rAAV6-based treatment of blood diseases.

A comprehensive association analysis between homocysteine metabolic pathway gene methylation and ischemic stroke in a Chinese hypertensive population.

BACKGROUND: Ischemic stroke (IS) is a serious global health burden. In order to improve our understanding of the risk factors associated with IS, we investigated the combined effect of the methylation of five genes related to the metabolism of homocysteine on developing IS. METHODS: Quantitative methylation-specific PCR was used to measure the levels of promoter methylation in hypertensive and stroke patients. The cutoff value calculated by the maximum Youden index was used to classify the levels of gene methylation as hypomethylation and hypermethylation. Logistic regression was used to explore the relationship between gene methylation and IS. RESULTS: The methylation levels of the genes encoding methylenetetrahydrofolate dehydrogenase 1 [MTHFD1], cystathionine ß-synthase [CBS], and dihydrofolate reductase [DHFR] in hypertensive patients were higher than those in stroke patients (all p < 0.01). MTHFD1 hypermethylation, CBS hypermethylation, and DHFR hypermethylation were protective factors for stroke after adjustment for confounding factors. Compared with individuals carrying none of the biomarkers, the ORs [95% CIs] for stroke of those with 1 and 2 elevated biomarkers were 4.068 [1.670-9.913] and 15.345 [6.198-37.994] after adjustment for confounding factors. The participants with a larger number of biomarkers had an increased risk of stroke (p for trend <0.001). For the combination biomarkers, the area under the curve of the receiver operating characteristic was 0.716. CONCLUSION: A significant linear relationship between the number of elevated biomarkers and the risk of stroke has been observed, suggesting that elevations of these biomarkers could be used for potentially predicting the disease.

Review: Radionuclide Molecular Imaging Targeting HER2 in Breast Cancer with a Focus on Molecular Probes into Clinical Trials and Small Peptides.

As the most frequently occurring cancer worldwide, breast cancer (BC) is the leading cause of cancer-related death in women. The overexpression of HER2 (human epidermal growth factor receptor 2) is found in about 15% of BC patients, and it is often associated with a poor prognosis due to the effect on cell proliferation, migration, invasion, and survival. As a result of the heterogeneity of BC, molecular imaging with HER2 probes can non-invasively, in real time, and quantitatively reflect the expression status of HER2 in tumors. This will provide a new approach for patients to choose treatment options and monitor treatment response. Furthermore, radionuclide molecular imaging has the potential of repetitive measurements, and it can help solve the problem of heterogeneous expression and conversion of HER2 status during disease progression or treatment. Different imaging probes of targeting proteins, such as monoclonal antibodies, antibody fragments, nanobodies, and affibodies, are currently in preclinical and clinical development. Moreover, in recent years, HER2-specific peptides have been widely developed for molecular imaging techniques for HER2-positive cancers. This article summarized different types of molecular probes targeting HER2 used in current clinical applications and the developmental trend of some HER2-specific peptides.

Strong fluorescence blinking of large-size all-inorganic perovskite nano-spheres.

We demonstrated strong fluorescence blinking on large all-inorganic perovskite (CsPbBr3) nano-spheres. By performing (time-resolved) micro-photoluminescence (µ-PL) measurements, the unique blinking characteristics of the as-grown nano-spheres with diameters of hundred nanometers, are clearly observed. Blinking has no obvious on/off states, which is different from the blinking characteristics of quantum dots. It is believed that the blinking of fluorescence is caused by metastable defect-induced trapping of carriers on the surface of the nano-spheres, because dramatically suppressed fluorescence blinking and the decay rates of ultrafast carriers are realized by surface passivation of the nano-spheres. Surface defects are closely related to the ambient atmosphere, which has been further confirmed by PL measurements of the as-grown nano-spheres in vacuum. Additionally, we also found that the fluorescence blinking was significantly suppressed as the sample size increased, which can be attributed to the large-size induced average effect on fluorescence blinking. These results may be important for understanding the mechanism of the fluorescence blinking of perovskite materials and for developing optical devices with good fluorescence stability.

[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.

A novel miR-375-HOXB3-CDCA3/DNMT3B regulatory circuitry contributes to leukemogenesis in acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a heterogeneous group of hematopoietic malignancies due to sophisticated genetic mutations and epigenetic dysregulation. MicroRNAs (miRNAs), a class of small non-coding RNAs, are important regulators of gene expression in all biological processes, including leukemogenesis. Recently, miR-375 has been reported to be a suppressive miRNA in multiple types of cancers, but its underlying anti-leukemia activity in AML is largely unknown. METHODS: Quantitative reverse transcriptase PCR (qRT-PCR) was used to measure the expression of miR-375 and HOXB3 in leukemic cells and normal controls. Targets of miR-375 were confirmed by western blot and luciferase assay. Phenotypic effects of miR-375 overexpression and HOXB3 knockdown were assessed using viability (trypan blue exclusion assay), colony formation/replating, as well as tumor xenograft assays in vivo. RESULTS: The expression of miR-375 was substantially decreased in leukemic cell lines and primary AML blasts compared with normal controls, because DNA hypermethylation of precursor-miR-375 (pre-miR-375) promoter was discovered in leukemic cells but not in normal controls. Lower expression of miR-375 predicted poor outcome in AML patients. Furthermore, forced expression of miR-375 not only decreased proliferation and colony formation in leukemic cells but also reduced xenograft tumor size and prolonged the survival time in a leukemia xenograft mouse model. Mechanistically, overexpression of miR-375 reduced HOXB3 expression and repressed the activity of a luciferase reporter through binding 3'-untranslated regions (3'-UTR) of HOXB3 mRNA. Overexpression of HOXB3 partially blocked miR-375-induced arrest of proliferation and reduction of colony number, suggesting that HOXB3 plays an important role in miR-375-induced anti-leukemia activity. Knockdown of HOXB3 by short hairpin RNAs reduced the expression of cell division cycle associated 3 (CDCA3), which decreased cell proliferation. Furthermore, HOXB3 induced DNA methyltransferase 3B (DNMT3B) expression to bind in the pre-miR-375 promoter and enhanced DNA hypermethylation of pre-miR-375, leading to the lower expression of miR-375. CONCLUSIONS: Collectively, we have identified a miR-375-HOXB3-CDCA3/DNMT3B regulatory circuitry which contributes to leukemogenesis and suggests a therapeutic strategy of restoring miR-375 expression in AML.

Congenital hypodysfibrinogenemia associated with a novel deletion of three residues (γAla289_Asp291del) in fibrinogen.

Hypodysfibrinogenemia is the least frequently reported congenital fibrinogen disorder, characterized by both quantity and quality defects of fibrinogen. In this study, we investigated the molecular basis of hypodysfibrinogenemia in a Chinese family. Functional fibrinogen was measured by Clauss method, and the antigenic fibrinogen was measured by immunoturbidimetry assay. All the exons and exon-intron boundaries of fibrinogen genes (FGA, FGB and FGG) were analysed by direct DNA sequencing. To further evaluate its molecular and functional characterizations, fibrinogen was purified from the plasma of propositus, then SDS-PAGE, fibrin polymerization, clot lysis, and electron microscopy scanning were all performed. The propositus showed a slight decrease of immunologic fibrinogen (1.52 g/L) but dramatically reduced functional fibrinogen (0.3 g/L). DNA sequencing revealed a novel heterozygous CCTTTGATG deletion in the exon 8 of FGG, leading to the deletion of Ala289, Phe290, and Asp291 in fibrinogen γ-chain. The polymerization of the fibrinogen from the propositus was markedly impaired, with prolonged lag period and decreased final turbidity. The fibrinogen clottability showed a reduced fraction of participating clot formation. While the clot lysis showed normal. Scanning electron microscopy revealed that the fibers of the propositus were thicker than normal, with larger pores and curlier meshworks. We conclude that γAla289_Asp291del is responsible for the hypodysfibrinogenemia in this case.

[Analysis of a pedigree affected with congenital hypofibrinogenemia due to heterozygous Ser313Ile mutation of fibrinogen γ chain gene].

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with congenital hypofibrinogenamia. METHODS: Peripheral blood samples were collected from 9 members from the pedigree. Routine coagulation tests including activated partial thromboplastin time (APTT), thrombin time (TT), the prothrombin time (PT) were carried out. The activity of fibrinogen (Fg: C) was measured using Clauss method, and fibrinogen antigen (Fg: Ag) was measured with immunoturbidimetry. All exons and exon-intron boundaries of the fibrinogen Aα, Bß and γ chain genes were amplified using PCR, which was followed by direct sequencing. Suspected mutation was confirmed by reverse sequencing. The mutant fibrinogen was analyzed with Swiss-PdbViewer. RESULTS: The proband showed prolonged APTT, PT and TT. Her functional fibrinogen (Fg: C) and antigen fibrinogen (Fg: Ag) levels were reduced to 0.69 g/L and 0.72 g/L, respectively. Her mother and grandmother also had a low levels of fibrinogen, which were 0.99 g/L and 0.83 g/L for Fg: C, 1.02 g/L and 0.87 g/L for Fg: Ag, respectively. The results of other members from the pedigree were all within the normal range. Genetic analysis reveled a heterozygous G>T mutation at nucleotide 7590 in exon 8 of γ gene in the proband, which was predicted to be a novel Ser313Ile mutation. The mutation was also found in her mother and grandmother. Model analysis showed that the Ser313Ile mutation disturbed the hydrogen bonds between Ser313, Asn319 and Asp320. Moreover, the mutation also altered the mutual electrostatic force and affected the folding and instability of the mutant fibrinogen. CONCLUSION: The heterozygous Ser313Ile mutation probably underlies the hypofibrinogenemia in this pedigree.

[Analysis of phenotypes and genetic mutations in two pedigrees affected with hereditary protein C deficiency].

OBJECTIVE: To explore the pathogenesis of protein C deficiency in two pedigrees through mutation detection and model analysis. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Synthesis, antitumor evaluation and 3D-QSAR studies of [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine derivatives.

A series of [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine derivatives have been synthesized and their structures were confirmed by single-crystal X-ray diffraction. Compared to some reported structures of 1,6-dihydro-1,2,4,5-tetrazine, these compounds can't be considered as having homoaromaticity. Their antiproliferative activities were evaluated against MCF-7, Bewo and HL-60 cells in vitro. Two compounds were highly effective against MCF-7, Bewo and HL-60 cells with IC50 values in 0.63-13.12µM. Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were carried out on 51 [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine derivatives with antiproliferative activity against MCF-7 cell. Models with good predictive abilities were generated with the cross validated q(2) values for CoMFA and CoMSIA being 0.716 and 0.723, respectively. Conventional r(2) values were 0.985 and 0.976, respectively. The results provide the tool for guiding the design and synthesis of novel and more potent tetrazine derivatives.

[Phenotypic and genetic analysis of two pedigrees affected with hereditary antithrombin deficiency].

OBJECTIVE: To explore the phenotype, genotype and molecular mechanism for two pedigrees affected with hereditary antithrombin (AT) deficiency. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Analysis of molecular pathogenesis and clinical phenotypes in 10 probands with inherited fibrinogen deficiency].

OBJECTIVE: To explore the molecular pathogenesis and clinical phenotypes in 10 probands with inherited fibrinogen (Fg) deficiency. METHODS: The diagnosis of hereditary Fg deficiency was validated by prothrombin time (PT), thrombin time (TT), Fg activity (Fg:C) and Fg antigen (Fg:Ag) in plasma. All of the exons and their flanking sequences of the Fg gene were analyzed by direct sequencing. Detected mutations were confirmed by reverse sequencing. RESULTS: The ranges of Fg:C and Fg:Ag in the 10 probands were 0.52-0.91 g/L and 0.62-2.98 g/L, respectively. Five of the probands had type I disorders, and 5 had type II disorders. Seven point mutations were identified, among which 6 have located in the D region. γThr277Arg, γAsp316His, γTrp208Leu and Lys232Thr were novel mutations, and αArg19Ser was first reported in Chinese. Four probands had the same mutation site (γArg275). As to the clinical manifestation, probands with type I disorders were asymptomatic or with mild or medium symptoms, while those belonged to type II disorders had moderate or serious symptoms. Two probands have carried an Arg275Cys mutation but had different clinical manifestations. CONCLUSION: Mutations of the Fg gene seem to aggregate to the D region of FGG in our region, and Arg275 is a common mutation. However, no correlation has been found between the mutation site and clinical manifestations.

[Genetic analysis of a pedigree with hereditary coagulation factor â ¦ deficiency].

OBJECTIVE: To identify potential mutations in a family affected with inherited factor Ⅶ (FⅦ) deficiency. METHODS: Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, FⅦ activity (FⅦ:C) and other coagulant parameters of the proband and 15 family members were measured. Potential mutations were screened in the pedigree by polymerase chain reaction and direct DNA sequencing. RESULTS: The PT of the proband and his younger brother was significantly prolonged to 39.0 s and 30.1 s, respectively. FⅦ:C of the proband and his younger brother was obviously reduced to 2% and 3%, respectively. FⅦ:C of his grandmother, maternal grandmother, aunt, father, mother, maternal uncle and maternal aunt was all below the normal range (80%-108%), which measured 68%, 54%, 71%, 73%, 62%, 72% and 59%, respectively. The other coagulant parameters were in the normal range. Two heterozygous mutations, g.11349G>A and g.11482T>G, both reside in exon 8 of the F7 gene, have resulted in p.Arg304Gln and p.His348Gln substitutions, were identified in the proband. The same mutations were also found in the proband's younger brother. Four maternal members in this family (grandmother, mother, maternal uncle and maternal aunt of the proband) were heterozygous for the p.Arg304Gln mutation, while three paternal members (grandmother, aunt and father of the proband) were heterozygous for the p.His348Gln mutation. CONCLUSION: The proband had inherited two independent mutations of the F7 gene including g.11349G>A and g.11482T>G from his mother and father, respectively. The compound heterozygous mutation probably explains the low FⅦ concentrations in this pedigree.

[Congenital hypofibrinogenemia associated with a novel mutation in FGG gene].

OBJECTIVE: To identify the genetic mutation underlying congenital hypofibrinogenamia in a Chinese pedigree. METHODS: Standard coagulation tests including the prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), plasminogen activity (PLG:A), D-Dimer (DD) and fibrin degradation products (FDP) were tested with fresh plasma using a STA-R analyzer. The activity of fibrinogen (Fg:C) and fibrinogen antigen (Fg:Ag) were measured respectively with the Clauss method and immunoturbidimetry. All exons and exon-intron boundaries of the fibrinogen Aα-, Bß-, and γ-chain genes (FGA, FGB and FGG) were amplified by PCR followed by direct sequencing. Suspected mutation was confirmed by reverse sequencing and analyzed with a Swiss-PdbViewer. RESULTS: The PT level in the proband was normal, while the APTT and TT were slightly prolonged. The functional and antigen fibrinogen levels were both significantly reduced (0.91 g/L and 0.95 g/L, respectively). Similar abnormalities were also found in her father, elder sister, son and niece. The coagulant parameters of her mother were all within the normal range. Genetic analysis has reveled a heterozygous A>C change at nucleotide 5864 in exon 7 of γ gene in the proband, predicting a novel Lys232Thr mutation. The proband's father, elder sister, son and niece were all carriers of the same mutation. Protein model analysis indicated that the Lys232Thr mutation did not disrupt the native network of hydrogen bonds, but has changed the mutual electrostatic forces, resulting in increased instability of the protein. CONCLUSION: The heterozygous Lys232Thr mutation identified in the FGG gene probably underlies the hypofibrinogenemia in this pedigree.

[Identification of a novel heterozygous mutation in a pedigree with hereditary coagulation factor XII deficiency].

OBJECTIVE: To identify potential mutation underlying hereditary coagulation factor XII (FXII) deficiency in a pedigree and explore its molecular pathogenesis. METHODS: Activated partial thromboplastin time (APTT), FXII activity (FXII:C) and FXII antigen(FXII:Ag) and other coagulant parameters of the proband and 5 family members were measured. Potential mutations in the 14 exons and intron-exon boundaries of the FXII gene were screened with polymerase chain reaction (PCR) and direct DNA sequencing. Suspected mutations were confirmed with reverse sequencing. Corresponding PCR fragments from other family members were also sequenced. RESULTS: APPT of the proband and his son were significantly prolonged to 121.5 s and 98.5 s, respectively. FXII:C and FXII:Ag of the proband and his son have reduced to 5%, 6.8% and 9%, 12.2%, respectively. Plasma plasminogen activity (PLG:A) in both individuals was slightly higher than the normal reference range. FXII:C of his second daughter and grandson were slightly reduced to 64% and 60%. FXII:C of the other family members were all in the normal range (72%-113%). A heterozygous missense mutation, g.8597G>A, was identified in exon 13 of the FXII gene in the proband, which resulted in an p.Asp538Asn substitution. For the promoter regions of the FXII gene, the genotype of the proband was 46TT. The same mutations and 46T/T were also found in the proband's son but not in other members of the family. The genotypes of the proband's spouse, eldest daughter and grandson were 46CT, and his second daughter was 46TT. CONCLUSION: The heterozygous mutation of g.8597G>A identified in exon 13 of FXII gene is a novel mutation. Heterozygous p.Asp538Asn mutation and 46TT in the FXII gene can cause hereditary FXII deficiency, which was probably responsible for the low FXII concentrations in this pedigree.