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Harris VA, Lin W, Perkins SJ. Analysis of 180 Genetic Variants in a New Interactive FX Variant Database Reveals Novel Insights into FX Deficiency. TH OPEN 2021; 5:e557-e569. [PMID: 35059555 PMCID: PMC8763577 DOI: 10.1055/a-1704-0841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/15/2021] [Indexed: 12/03/2022] Open
Abstract
Coagulation factor X (FX), often termed as Stuart–Prower factor, is a plasma glycoprotein composed of the γ-carboxyglutamic acid (GLA) domain, two epidermal growth factor domains (EGF-1 and EGF-2), and the serine protease (SP) domain. FX plays a pivotal role in the coagulation cascade, activating thrombin to promote platelet plug formation and prevent excess blood loss. Genetic variants in FX disrupt coagulation and lead to FX or Stuart–Prower factor deficiency. To better understand the relationship between FX deficiency and disease severity, an interactive FX variant database has been set up at
https://www.factorx-db.org
, based on earlier web sites for the factor-XI and -IX coagulation proteins. To date (April 2021), we report 427 case reports on FX deficiency corresponding to 180 distinct
F10
genetic variants. Of
these, 149 are point variants (of which 128 are missense), 22 are deletions, 3 are insertions, and 6 are polymorphisms. FX variants are phenotypically classified as being type I or II. Type-I variants involve the simultaneous reduction of FX coagulant activity (FX:C) and FX antigen levels (FX:Ag), whereas type-II variants involve a reduction in FX:C with normal FX:Ag plasma levels. Both types of variants were distributed throughout the FXa protein structure. Analyses based on residue surface accessibilities showed the most damaging variants to occur at residues with low accessibilities. The interactive FX web database provides a novel easy-to-use resource for clinicians and scientists to improve the understanding of FX deficiency. Guidelines are provided for clinicians who wish to use the database for diagnostic purposes.
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Affiliation(s)
- Victoria A. Harris
- Research Department of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
| | - Weining Lin
- Research Department of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
| | - Stephen J. Perkins
- Research Department of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
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Molecular mechanism of a novel Ser362Asn mutation causing inherited FX deficiency in a Chinese family. Int J Hematol 2020; 112:8-16. [PMID: 32285359 DOI: 10.1007/s12185-020-02877-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 10/24/2022]
Abstract
Factor X (FX) deficiency is an inherited autosomal recessive bleeding disorder. Here, we analyzed a proband with FX deficiency in a Chinese family. Genetic analysis revealed that the proband and his affected sister was homozygous for c.1085G>A mutation, corresponding to a Ser362Asn substitution. In vitro expression experiments showed that the FX Ser362Asn mutation led to a significant reduction in activity levels in the culture medium. This Ser to Asn substitution may change the shape of the active site. Moreover, simulations of molecular dynamics indicated that the binding energy of the FX Ser362Asn to the substrate is higher than that of wild type and the side-chain conformation of the catalytic residue His276 (His42) is changed. This impairs the conformational switch of the protein from zymogen to proteinase, thus causing the functional defect of FX protein. Our findings suggest that the Ser362Asn substitution is a pathogenic mutation that causes inherited FX deficiency.
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Chan JKY, Gil-Farina I, Johana N, Rosales C, Tan YW, Ceiler J, Mcintosh J, Ogden B, Waddington SN, Schmidt M, Biswas A, Choolani M, Nathwani AC, Mattar CNZ. Therapeutic expression of human clotting factors IX and X following adeno-associated viral vector-mediated intrauterine gene transfer in early-gestation fetal macaques. FASEB J 2018; 33:3954-3967. [PMID: 30517034 PMCID: PMC6404563 DOI: 10.1096/fj.201801391r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Adeno-associated viral vectors (AAVs) achieve stable therapeutic expression without long-term toxicity in adults with hemophilia. To avert irreversible complications in congenital disorders producing early pathogenesis, safety and efficacy of AAV-intrauterine gene transfer (IUGT) requires assessment. We therefore performed IUGT of AAV5 or -8 with liver-specific promoter-1 encoding either human coagulation factors IX (hFIX) or X (hFX) into Macaca fascicularis fetuses at ∼0.4 gestation. The initial cohort received 1 × 1012 vector genomes (vgs) of AAV5-hFIX (n = 5; 0.45 × 1013 vg/kg birth weight), resulting in ∼3.0% hFIX at birth and 0.6–6.8% over 19–51 mo. The next cohort received 0.2–1 × 1013 vg boluses. AAV5-hFX animals (n = 3; 3.57 × 1013 vg/kg) expressed <1% at birth and 9.4–27.9% up to 42 mo. AAV8-hFIX recipients (n = 3; 2.56 × 1013 vg/kg) established 4.2–41.3% expression perinatally and 9.8–25.3% over 46 mo. Expression with AAV8-hFX (n = 6, 3.12 × 1013 vg/kg) increased from <1% perinatally to 9.8–13.4% >35 mo. Low expressers (<1%, n = 3) were postnatally challenged with 2 × 1011 vg/kg AAV5 resulting in 2.4–13.2% expression and demonstrating acquired tolerance. Linear amplification–mediated-PCR analysis demonstrated random integration of 57–88% of AAV sequences retrieved from hepatocytes with no events occurring in or near oncogenesis-associated genes. Thus, early-IUGT in macaques produces sustained curative expression related significantly to integrated AAV in the absence of clinical toxicity, supporting its therapeutic potential for early-onset monogenic disorders.—Chan, J. K. Y., Gil-Farina I., Johana, N., Rosales, C., Tan, Y. W., Ceiler, J., Mcintosh, J., Ogden, B., Waddington, S. N., Schmidt, M., Biswas, A., Choolani, M., Nathwani, A. C., Mattar, C. N. Z. Therapeutic expression of human clotting factors IX and X following adeno-associated viral vector–mediated intrauterine gene transfer in early-gestation fetal macaques.
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Affiliation(s)
- Jerry K Y Chan
- Reproductive Medicine, KK Women's and Children's Hospital, Singapore, Singapore.,Cancer and Stem Cell Biology Program, Duke-National University of Singapore (NUS) Medical School, Singapore
| | - Irene Gil-Farina
- Department of Translational Oncology, German Cancer Research Center/National Center for Tumor Diseases, Heidelberg, Germany
| | - Nuryanti Johana
- Reproductive Medicine, KK Women's and Children's Hospital, Singapore, Singapore
| | - Cecilia Rosales
- University College London (UCL) Cancer Institute, University College London, London, United Kingdom
| | - Yi Wan Tan
- Reproductive Medicine, KK Women's and Children's Hospital, Singapore, Singapore
| | - Jessika Ceiler
- Department of Translational Oncology, German Cancer Research Center/National Center for Tumor Diseases, Heidelberg, Germany
| | - Jenny Mcintosh
- Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Bryan Ogden
- SingHealth Experimental Medicine Centre, Singapore Health Services Pte, Singapore, Singapore
| | - Simon N Waddington
- Institute for Women's Health, University College London, London, United Kingdom.,Faculty of Health Sciences, Wits/South African Medical Research Council (SAMRC), Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa; and
| | - Manfred Schmidt
- University College London (UCL) Cancer Institute, University College London, London, United Kingdom.,GeneWerk, Heidelberg, Germany
| | - Arijit Biswas
- Department of Translational Oncology, German Cancer Research Center/National Center for Tumor Diseases, Heidelberg, Germany
| | - Mahesh Choolani
- Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Amit C Nathwani
- University College London (UCL) Cancer Institute, University College London, London, United Kingdom
| | - Citra N Z Mattar
- Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Öner AF, Celkan T, Timur Ç, Norton M, Kavaklı K. Use of a High-Purity Factor X Concentrate in Turkish Subjects with Hereditary Factor X Deficiency: Post Hoc Cohort Subanalysis of a Phase 3 Study. Turk J Haematol 2018; 35:129-133. [PMID: 29545231 PMCID: PMC5972335 DOI: 10.4274/tjh.2017.0446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hereditary factor X (FX) deficiency is a rare bleeding disorder more prevalent in countries with high rates of consanguineous marriage. In a prospective, open-label, multicenter phase 3 study, 25 IU/kg plasma-derived factor X (pdFX) was administered as on-demand treatment or short-term prophylaxis for 6 months to 2 years. In Turkish subjects (n=6), 60.7% of bleeds were minor. A mean of 1.03 infusions were used to treat each bleed, and mean total dose per bleed was 25.38 IU/kg. Turkish subjects rated pdFX efficacy as excellent or good for all 84 assessable bleeds; investigators judged overall pdFX efficacy to be excellent or good for all subjects. Turkish subjects had 51 adverse events; 96% with known severity were mild/moderate, and 1 (infusion-site pain) was possibly pdFX-related. These results demonstrate that 25 IU/kg pdFX is safe and effective in this Turkish cohort (ClinicalTrials.gov identifier: NCT00930176).
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Affiliation(s)
- Ahmet F Öner
- Yüzüncü Yıl University Faculty of Medicine, Department of Pediatric Hematology, Van, Turkey
| | - Tiraje Celkan
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Hematology and Oncology, İstanbul, Turkey
| | - Çetin Timur
- İstanbul Medeniyet University, Göztepe Training and Research Hospital, Clinic of Pediatric Hematology, İstanbul, Turkey
| | - Miranda Norton
- Bio Products Laboratory Ltd., Elstree, Hertfordshire, United Kingdom
| | - Kaan Kavaklı
- Ege University Faculty of Medicine, Department of Pediatric Hematology, İzmir, Turkey
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A novel factor X mutation Cys81 by Arg and a reported factor VII polymorphism Arg353 replaced by Gln co-occured in a patient. Blood Coagul Fibrinolysis 2017; 29:67-74. [PMID: 29251640 DOI: 10.1097/mbc.0000000000000691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
: Coagulation factor X and factor VII (FVII) are both very important components in blood coagulation. To study the molecular pathogenic mechanism of the inherited factor X and FVII deficiency, the factor X activity (FX:C) and FVII activity were tested with one-stage clotting methods. The factor X antigen and factor FVII antigen were tested with ELISA. All the exons, intron-exon boundaries and 5',3'-flanking regions of F10 and F7 genes were amplified by PCR with direct sequencing. The ClustalX software was used to analyze the conservative property of the mutation sites. The PolyPhen-2 and Sorting Intolerant From Tolerant (SIFT) online bioinformatics softwares were taken to predict whether the point mutation could affect protein function. The software Swiss-pdb Viewer was brought to analyze the impact of mutations on the structure and function of the protein. The thrombin generation tests were applied to evaluate whether there were obstacles in producing thrombin about the mutant protein. The FX:C and FVII activity of the proband were reduced to 35 and 42%, and the factor X antigen and factor FVII antigen were decreased to 43 and 55%, simultaneously. Correspondingly, a FX:Cys81Arg (Cys81 by Arg) mutation and a FVII:Arg353 replaced by Gln polymorphism were detected in the proband. The Cys81 of factor X was conserved among homologous species, but the Arg353 of FVII was not. All softwares analysis results indicated protein features and structures might be affected by the mutation and the polymorphism. And the thrombin generation tests showed that the mutant protein had obstacles in thrombin generation. We identified a FX:Cys81Arg mutation and a FVII:Arg353 replaced by Gln polymorphism in the proband. And they accounted for the decrease of the activity and antigen of factor X and FVII. Of note, the Cys81Arg of factor X was first reported in the world.
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