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Todaro AM, Radu CM, Ciccone M, Toffanin S, Serino ML, Campello E, Bulato C, Lunghi B, Gemmati D, Cuneo A, Hackeng TM, Simioni P, Bernardi F, Castoldi E. In vitro and ex vivo rescue of a nonsense mutation responsible for severe coagulation factor V deficiency. J Thromb Haemost 2024; 22:410-422. [PMID: 37866515 DOI: 10.1016/j.jtha.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/24/2023]
Abstract
BACKGROUND Coagulation factor V (FV) deficiency is a rare bleeding disorder that is usually managed with fresh-frozen plasma. Patients with nonsense mutations may respond to treatment with readthrough agents. OBJECTIVES To investigate whether the F5 p.Arg1161Ter mutation, causing severe FV deficiency in several patients, would be amenable to readthrough therapy. METHODS F5 mRNA and protein expression were evaluated in a F5 p.Arg1161Ter-homozygous patient. Five readthrough agents with different mechanisms of action, i.e. G418, ELX-02, PTC-124, 2,6-diaminopurine (2,6-DAP), and Amlexanox, were tested in in vitro and ex vivo models of the mutation. RESULTS The F5 p.Arg1161Ter-homozygous patient showed residual F5 mRNA and functional platelet FV, indicating detectable levels of natural readthrough. COS-1 cells transfected with the FV-Arg1161Ter cDNA expressed 0.7% FV activity compared to wild-type. Treatment with 0-500 μM G418, ELX-02, and 2,6-DAP dose-dependently increased FV activity up to 7.0-fold, 3.1-fold, and 10.8-fold, respectively, whereas PTC-124 and Amlexanox (alone or in combination) were ineffective. These findings were confirmed by thrombin generation assays in FV-depleted plasma reconstituted with conditioned media of treated cells. All compounds except ELX-02 showed some degree of cytotoxicity. Ex vivo differentiated megakaryocytes of the F5 p.Arg1161Ter-homozygous patient, which were negative at FV immunostaining, turned positive after treatment with all 5 readthrough agents. Notably, they were also able to internalize mutant FV rescued with G418 or 2,6-DAP, which would be required to maintain the crucial platelet FV pool in vivo. CONCLUSION These findings provide in vitro and ex vivo proof-of-principle for readthrough-mediated rescue of the F5 p.Arg1161Ter mutation.
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Affiliation(s)
- Alice M Todaro
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Claudia M Radu
- Department of Medicine, Thrombotic and Haemorrhagic Diseases Unit, Padua University Medical School, Padua, Italy
| | - Maria Ciccone
- Department of Medical Sciences, Section of Haematology, Sant'Anna Hospital, Ferrara University, Ferrara, Italy
| | - Serena Toffanin
- Department of Medicine, Thrombotic and Haemorrhagic Diseases Unit, Padua University Medical School, Padua, Italy
| | - M Luisa Serino
- Department of Medical Sciences, Section of Haematology, Sant'Anna Hospital, Ferrara University, Ferrara, Italy
| | - Elena Campello
- Department of Medicine, Thrombotic and Haemorrhagic Diseases Unit, Padua University Medical School, Padua, Italy
| | - Cristiana Bulato
- Department of Medicine, Thrombotic and Haemorrhagic Diseases Unit, Padua University Medical School, Padua, Italy
| | - Barbara Lunghi
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, Ferrara, Italy
| | - Donato Gemmati
- Department of Translational Medicine, Haemostasis & Thrombosis Centre, Ferrara University, Ferrara, Italy
| | - Antonio Cuneo
- Department of Medical Sciences, Section of Haematology, Sant'Anna Hospital, Ferrara University, Ferrara, Italy
| | - Tilman M Hackeng
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Paolo Simioni
- Department of Medicine, Thrombotic and Haemorrhagic Diseases Unit, Padua University Medical School, Padua, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, Ferrara University, Ferrara, Italy
| | - Elisabetta Castoldi
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
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Dorgalaleh A, Bahraini M, Shams M, Parhizkari F, Dabbagh A, Naderi T, Fallah A, Fazeli A, Ahmadi SE, Samii A, Daneshi M, Heydari F, Tabibian S, Tavasoli B, Noroozi-Aghideh A, Tabatabaei T, Gholami MS. Molecular basis of rare congenital bleeding disorders. Blood Rev 2022; 59:101029. [PMID: 36369145 DOI: 10.1016/j.blre.2022.101029] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/26/2022] [Accepted: 10/23/2022] [Indexed: 11/11/2022]
Abstract
Rare bleeding disorders (RBDs), including factor (F) I, FII, FV, FVII, combined FV and FVIII (CF5F8), FXI, FXIII and vitamin-K dependent coagulation factors (VKCF) deficiencies, are a heterogeneous group of hemorrhagic disorder with a variable bleeding tendency. RBDs are due to mutation in underlying coagulation factors genes, except for CF5F8 and VKCF deficiencies. FVII deficiency is the most common RBD with >330 variants in the F7 gene, while only 63 variants have been identified in the F2 gene. Most detected variants in the affected genes are missense (>50% of all RBDs), while large deletions are the rarest, having been reported in FVII, FX, FXI and FXIII deficiencies. Most were located in the catalytic and activated domains of FXI, FX, FXIII and prothrombin deficiencies. Understanding the proper molecular basis of RBDs not only can help achieve a timely and cost-effective diagnosis, but also can help to phenotype properties of the disorders.
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Sarkar A, Panati K, Narala VR. Code inside the codon: The role of synonymous mutations in regulating splicing machinery and its impact on disease. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2022; 790:108444. [PMID: 36307006 DOI: 10.1016/j.mrrev.2022.108444] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 10/10/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
In eukaryotes, precise pre-mRNA processing, including alternative splicing, is essential to carry out the intricate protein translation process. Both point mutations (that alter the translated protein sequence) and synonymous mutations (that do not alter the translated protein sequence) are capable of affecting the splicing process. Synonymous mutations are known to affect gene expression via altering mRNA stability, mRNA secondary structure, splicing processes, and translational kinetics. In higher eukaryotes, precise splicing is regulated by three weakly conserved cis-elements, 5' and 3' splice sites and the branch site. Many other cis-acting elements (exonic/intronic splicing enhancers and silencers) and trans-acting splicing factors (serine and arginine-rich proteins and heterogeneous nuclear ribonucleoproteins) have also been found to enhance or suppress the splicing process. The appearance of synonymous mutations in cis-acting elements can alter the splicing process by changing the binding pattern of splicing factors to exonic splicing enhancers or silencer motifs. This results in exon skipping, intron retention, and various other forms of alternative splicing, eventually leading to the emergence of a wide range of diseases. The focus of this review is to elucidate the role of synonymous mutations and their impact on abnormal splicing mechanisms. Further, this study highlights the function of synonymous mutation in mediating abnormal splicing in cancer and development of X-linked, and autosomal inherited diseases.
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Affiliation(s)
- Avik Sarkar
- Department of Zoology, Vidyasagar University, Midnapore, West Bengal 721102, India
| | - Kalpana Panati
- Department of Biotechnology, Government College for Men, Kadapa 516004, India
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Wei Y, He Y, Guo X. Clinical Phenotype and Genetic Analysis of Twins With Congenital Coagulation Factor V Deficiency. J Pediatr Hematol Oncol 2022; 44:e482-e486. [PMID: 34387626 PMCID: PMC8876379 DOI: 10.1097/mph.0000000000002261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/27/2021] [Indexed: 12/02/2022]
Abstract
OBJECTIVE The aim was to investigate the clinical characteristics and molecular pathogenic mechanism of twins with congenital factor V (FV) deficiency. METHODS We comprehensively analyzed the clinical manifestations and laboratory test results of a set of twins and their parents and performed point mutation analysis with direct high-throughput exon sequencing. RESULTS The prothrombin time and activated partial thromboplastin time were prolonged for both probands, and the FV activity levels were 13.0% and 9.8%. Next-generation sequencing showed that the affected individuals harbored a paternal c.5113A>C (p.S1705R) and a maternal c.4949C>T (p.A1650V) heterozygous variants in the FV gene, which conformed to an autosomal recessive inheritance pattern. This is the first report of these point mutations. The older boy also had a congenital patent foramen ovale. CONCLUSION In this set of twins, missense mutations of the FV gene were related to congenital FV deficiency but unrelated to the patent foramen ovale observed in the older boy.
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Affiliation(s)
- Yanhui Wei
- Department of Graduate School, Xinxiang Medical University, Xinxiang
| | - Yuzhuo He
- Department of Haematology, Puyang Oilfield General Hospital, Puyang, Henan Province, China
| | - Xuejun Guo
- Department of Haematology, Puyang Oilfield General Hospital, Puyang, Henan Province, China
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5
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Antisense-Mediated Down-Regulation of Factor V-Short Splicing in a Liver Cell Line Model. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11209621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coagulation factor V (FV) is a liver-derived protein encoded by the F5 gene. Alternative splicing of F5 exon 13 produces a low-abundance splicing isoform, known as FV-short, which binds the anticoagulant protein tissue factor pathway inhibitor (TFPIα) with high affinity, stabilising it in the circulation and potently enhancing its anticoagulant activity. Accordingly, rare F5 gene mutations that up-regulate FV-short splicing are associated with bleeding. In this study we have explored the possibility of decreasing FV-short splicing by antisense-based splicing modulation. To this end, we have designed morpholino antisense oligonucleotides (MAOs) targeting the FV-short-specific donor and acceptor splice sites and tested their efficacy in a liver cell line (HepG2) that naturally expresses full-length FV and FV-short. Cells were treated with 0–20 µM MAO, and full-length FV and FV-short mRNA expression was analysed by RT-(q)PCR. Both MAOs, alone or in combination, decreased the FV-short/full-length FV mRNA ratio down to ~50% of its original value in a specific and dose-dependent manner. This pilot study provides proof-of-principle for the possibility to decrease FV-short expression by antisense-mediated splicing modulation. In turn, this may form the basis for novel therapeutic approaches to bleeding disorders caused by FV-short over-expression and/or elevated TFPIα (activity) levels.
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Bernal S, Pelaez I, Alias L, Baena M, De Pablo-Moreno JA, Serrano LJ, Camero MD, Tizzano EF, Berrueco R, Liras A. High Mutational Heterogeneity, and New Mutations in the Human Coagulation Factor V Gene. Future Perspectives for Factor V Deficiency Using Recombinant and Advanced Therapies. Int J Mol Sci 2021; 22:9705. [PMID: 34575869 PMCID: PMC8465496 DOI: 10.3390/ijms22189705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 02/07/2023] Open
Abstract
Factor V is an essential clotting factor that plays a key role in the blood coagulation cascade on account of its procoagulant and anticoagulant activity. Eighty percent of circulating factor V is produced in the liver and the remaining 20% originates in the α-granules of platelets. In humans, the factor V gene is about 80 kb in size; it is located on chromosome 1q24.2, and its cDNA is 6914 bp in length. Furthermore, nearly 190 mutations have been reported in the gene. Factor V deficiency is an autosomal recessive coagulation disorder associated with mutations in the factor V gene. This hereditary coagulation disorder is clinically characterized by a heterogeneous spectrum of hemorrhagic manifestations ranging from mucosal or soft-tissue bleeds to potentially fatal hemorrhages. Current treatment of this condition consists in the administration of fresh frozen plasma and platelet concentrates. This article describes the cases of two patients with severe factor V deficiency, and of their parents. A high level of mutational heterogeneity of factor V gene was identified, nonsense mutations, frameshift mutations, missense changes, synonymous sequence variants and intronic changes. These findings prompted the identification of a new mutation in the human factor V gene, designated as Jaén-1, which is capable of altering the procoagulant function of factor V. In addition, an update is provided on the prospects for the treatment of factor V deficiency on the basis of yet-to-be-developed recombinant products or advanced gene and cell therapies that could potentially correct this hereditary disorder.
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Affiliation(s)
- Sara Bernal
- Department of Genetics, Santa Creu i Sant Pau Hospital and IIB Sant Pau, 08041 Barcelona, Spain; (S.B.); (L.A.); (M.B.)
- CIBERER. U-705, 18014 Barcelona, Spain
| | - Irene Pelaez
- Department of Pediatric and Oncohematology, University Hospital Virgen de las Nieves, 18014 Granada, Spain;
| | - Laura Alias
- Department of Genetics, Santa Creu i Sant Pau Hospital and IIB Sant Pau, 08041 Barcelona, Spain; (S.B.); (L.A.); (M.B.)
- CIBERER. U-705, 18014 Barcelona, Spain
| | - Manel Baena
- Department of Genetics, Santa Creu i Sant Pau Hospital and IIB Sant Pau, 08041 Barcelona, Spain; (S.B.); (L.A.); (M.B.)
| | - Juan A. De Pablo-Moreno
- Department of Genetic, Physiology and Microbiology, School of Biology, Complutense University, 28040 Madrid, Spain; (J.A.D.P.-M.); (L.J.S.)
| | - Luis J. Serrano
- Department of Genetic, Physiology and Microbiology, School of Biology, Complutense University, 28040 Madrid, Spain; (J.A.D.P.-M.); (L.J.S.)
| | - M. Dolores Camero
- Association for the Investigation and Cure of Factor V Deficiency, 23002 Jaén, Spain;
| | - Eduardo F. Tizzano
- Department of Clinical and Molecular Genetics, University Hospital Vall d’Hebron and Medicine Genetics Group, Vall d’Hebron Research Institute, 08035 Barcelona, Spain;
| | - Ruben Berrueco
- Pediatric Hematology Department, Hospital Sant Joan de Déu, University of Barcelona and Research Institute Hospital Sant Joan de Déu, 08950 Barcelona, Spain;
| | - Antonio Liras
- Department of Genetic, Physiology and Microbiology, School of Biology, Complutense University, 28040 Madrid, Spain; (J.A.D.P.-M.); (L.J.S.)
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Novel splicing (c.6529-1G>T) and missense (c.1667G>A) mutations causing factor V deficiency. Blood Coagul Fibrinolysis 2021; 32:344-348. [PMID: 33769317 DOI: 10.1097/mbc.0000000000001036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Congenital factor V deficiency (FVD) is a rare bleeding disorder. In this study, we investigated the genetic basis in an African American patient with factor V activity 3%. Custom sequence capture and targeted next-generation (NGS) sequencing of the F5 gene were undertaken followed by PCR and Sanger sequencing. Two novel variants were identified. In silico analyses correlated clinically with the patient's factor V activity and hemorrhagic tendency. A review of the literature regarding these genomic alterations is presented. We described two novel mutations causing moderate FVD. The first, Chr1:g.169483698C>A with cDNA change (F5):c.6529-1G>T, occurred in a conserved nucleotide at the canonical acceptor splice site of intron 24. The second, Chr1:g.169515775C>T with cDNA change (F5):c.1667G>A, was a missense variant of exon 11, affecting a highly conserved amino acid in the A2 domain. Further research into the mechanisms of F5 mutations leading to FVD and residual factor V expression are needed.
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A novel mutation (Ser951LeufsTer8) in F5 gene leads to hereditary coagulation factor V deficiency. Blood Coagul Fibrinolysis 2021; 32:140-145. [PMID: 33443922 DOI: 10.1097/mbc.0000000000001003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The current study aims to explore the phenotype and genotype of a novel mutation (Ser951LeufsTer8) of F5 gene combined with polymorphism (R485K) in a family of hereditary coagulation factor V deficiency. The factor V activity and antigen were tested with clotting assay and ELISA. The F5 gene was amplified by PCR with direct sequencing and TA-clone-sequenced. The protein structure and harmfulness of the mutation were studied by Swiss-PdbViewer and bioinformatics software. The prothrombin time and activated partial thromboplastin time of proband were significantly prolonged, factor V activity and factor V antigen both were reduced to less than 20%. Sequencing analysis detected proband with Ser951LeufsTer8 and R485K (Arg513Lys), four family members with novel mutation and their factor V activity and factor V antigen were all decreased about 50%. The Ser951LeufsTer8 is associated with decrease in the factor V level of the family, and it is the first mutation report in the position (Ser951LeufsTer8) with factor V deficiency.
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Analysis of phenotype and genotype of a family with hereditary coagulation factor V deficiency caused by the compound heterozygous mutations. Blood Coagul Fibrinolysis 2020; 31:485-489. [PMID: 32833806 DOI: 10.1097/mbc.0000000000000946] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
: To analyze the causative gene and the molecular pathogenesis in a pedigree with compound hereditary coagulation factor V deficiency. Routine blood coagulation indexes and factor V antigen (FV:Ag) were detected by the one-stage clotting method and ELISA. Function of the mutant protein was evaluated by the method Calibrated Automated Thrombogram (CAT). The factor V gene was amplified by PCR with direct sequencing. The possible impact of the mutations were analyzed by bioinformatics tools. The proband's factor V activity and FV:Ag were reduced to 3 and 6%. Gene sequencing revealed compound heterozygous mutations c.911G>A (Gly276Glu) in exon 6 and c.5343C>G (Ser1781Arg) in exon 16. The thrombin generation test showed that the mutant protein markedly decreased thrombin. Bioinformatics indicated that mutations were deleterious. The compound heterozygous mutations Gly276Glu and Ser1781Arg were responsible for the decrease of factor V activity and FV:Ag, of which Ser1781Arg was first reported in the world.
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Li M, Lu X, Dong J, Yao Z, Wu Y, Rao H, Huang X, Chen X, Huang Y, Wu Y. A synonymous mutation in exon 39 of FBN1 causes exon skipping leading to Marfan syndrome. Genomics 2020; 112:3856-3861. [PMID: 32562828 DOI: 10.1016/j.ygeno.2020.06.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/13/2020] [Accepted: 06/15/2020] [Indexed: 11/15/2022]
Abstract
Marfan syndrome is a heritable autosomal-dominant connective tissue disorder and it was typically caused by mutations in FBN1. However, the synonymous mutation was seldom recorded to be related to Marfan syndrome. Hereon, Multiplex ligation-dependent probe amplification failed to detect a copy number variant involving FBN1 but a synonymous mutation c.4773A > G (p.Gly1591Gly) was identified by NGS in exon 39. RNA was extracted from patient's aortic tissue and reverse polymerase chain reaction demonstrated the presence of a shortened mRNA transcript. Results of minigene models indicated that c.4773A > G was bona fide responsibility for the aberrant splicing pattern, and artificial mutations of c.4773A > C and c.4773A > T also gave rise to fragments with exon 39 entire skipped. Together, the novel synonymous mutations in c.4773 position (A > G, C, T), middle of exon 39 of FBN1 gene, was found to be associated with Marfan syndrome by altering the splicing pattern of pre-mRNA.
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Affiliation(s)
- Mingjie Li
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Xinxin Lu
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Jian Dong
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Zuwu Yao
- Department of Cardiovascular Surgery, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Yinlong Wu
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Huiying Rao
- Department of Ophthalmology, Fujian Provincial Hospital, Fuzhou 350001, China
| | - Xiaoli Huang
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Xijun Chen
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Yi Huang
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China
| | - Yan'an Wu
- Department of Clinical Laboratory, Fujian Provincial Hospital, Shengli Clinical Medical College, Fujian Medical University, Fuzhou 350001, China.
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Diagnostic high-throughput sequencing of 2396 patients with bleeding, thrombotic, and platelet disorders. Blood 2020; 134:2082-2091. [PMID: 31064749 DOI: 10.1182/blood.2018891192] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/22/2019] [Indexed: 12/17/2022] Open
Abstract
A targeted high-throughput sequencing (HTS) panel test for clinical diagnostics requires careful consideration of the inclusion of appropriate diagnostic-grade genes, the ability to detect multiple types of genomic variation with high levels of analytic sensitivity and reproducibility, and variant interpretation by a multidisciplinary team (MDT) in the context of the clinical phenotype. We have sequenced 2396 index patients using the ThromboGenomics HTS panel test of diagnostic-grade genes known to harbor variants associated with rare bleeding, thrombotic, or platelet disorders (BTPDs). The molecular diagnostic rate was determined by the clinical phenotype, with an overall rate of 49.2% for all thrombotic, coagulation, platelet count, and function disorder patients and a rate of 3.2% for patients with unexplained bleeding disorders characterized by normal hemostasis test results. The MDT classified 745 unique variants, including copy number variants (CNVs) and intronic variants, as pathogenic, likely pathogenic, or variants of uncertain significance. Half of these variants (50.9%) are novel and 41 unique variants were identified in 7 genes recently found to be implicated in BTPDs. Inspection of canonical hemostasis pathways identified 29 patients with evidence of oligogenic inheritance. A molecular diagnosis has been reported for 894 index patients providing evidence that introducing an HTS genetic test is a valuable addition to laboratory diagnostics in patients with a high likelihood of having an inherited BTPD.
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Ferraresi P, Balestra D, Guittard C, Buthiau D, Pan-Petesh B, Maestri I, Farah R, Pinotti M, Giansily-Blaizot M. Next-generation sequencing and recombinant expression characterized aberrant splicing mechanisms and provided correction strategies in factor VII deficiency. Haematologica 2019; 105:829-837. [PMID: 31273093 PMCID: PMC7049351 DOI: 10.3324/haematol.2019.217539] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/02/2019] [Indexed: 01/22/2023] Open
Abstract
Despite the exhaustive screening of F7 gene exons and exon-intron boundaries and promoter region, a significant proportion of mutated alleles remains unidentified in patients with coagulation factor VII deficiency. Here, we applied next-generation sequencing to 13 FVII-deficient patients displaying genotype-phenotype discrepancies upon conventional sequencing, and identified six rare intronic variants. Computational analysis predicted splicing effects for three of them, which would strengthen (c.571+78G>A; c.806-329G>A) or create (c.572-392C>G) intronic 5′ splice sites (5′ss). In F7 minigene assays, the c.806-329G>A was ineffective while the c.571+78G>A change led to usage of the +79 cryptic 5′ss with only trace levels of correct transcripts (3% of wild-type), in accordance with factor VII activity levels in homozygotes (1-3% of normal). The c.572-392C>G change led to pseudo-exonization and frame-shift, but also substantial levels of correct transcripts (approx. 70%). However, this variant was associated with the common F7 polymorphic haplotype, predicted to further decrease factor VII levels; this provided some kind of explanation for the 10% factor VII levels in the homozygous patient. Intriguingly, the effect of the c.571+78G>A and c.572-392C>G changes, and particularly of the former (the most severe and well-represented in our cohort), was counteracted by antisense U7snRNA variants targeting the intronic 5′ss, thus demonstrating their pathogenic role. In conclusion, the combination of next-generation sequencing of the entire F7 gene with the minigene expression studies elucidated the molecular bases of factor VII deficiency in 10 of 13 patients, thus improving diagnosis and genetic counseling. It also provided a potential therapeutic approach based on antisense molecules that has been successfully exploited in other disorders.
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Affiliation(s)
- Paolo Ferraresi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Dario Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Caroline Guittard
- Department of Biological Haematology, CHU Montpellier, Université Montpellier, Montpellier, France
| | - Delphine Buthiau
- Department of Biological Haematology, CHU Montpellier, Université Montpellier, Montpellier, France
| | | | - Iva Maestri
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Roula Farah
- Department of Pediatrics, Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Muriel Giansily-Blaizot
- Department of Biological Haematology, CHU Montpellier, Université Montpellier, Montpellier, France
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Balestra D, Branchini A. Molecular Mechanisms and Determinants of Innovative Correction Approaches in Coagulation Factor Deficiencies. Int J Mol Sci 2019; 20:ijms20123036. [PMID: 31234407 PMCID: PMC6627357 DOI: 10.3390/ijms20123036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/07/2019] [Accepted: 06/18/2019] [Indexed: 02/07/2023] Open
Abstract
Molecular strategies tailored to promote/correct the expression and/or processing of defective coagulation factors would represent innovative therapeutic approaches beyond standard substitutive therapy. Here, we focus on the molecular mechanisms and determinants underlying innovative approaches acting at DNA, mRNA and protein levels in inherited coagulation factor deficiencies, and in particular on: (i) gene editing approaches, which have permitted intervention at the DNA level through the specific recognition, cleavage, repair/correction or activation of target sequences, even in mutated gene contexts; (ii) the rescue of altered pre-mRNA processing through the engineering of key spliceosome components able to promote correct exon recognition and, in turn, the synthesis and secretion of functional factors, as well as the effects on the splicing of missense changes affecting exonic splicing elements; this section includes antisense oligonucleotide- or siRNA-mediated approaches to down-regulate target genes; (iii) the rescue of protein synthesis/function through the induction of ribosome readthrough targeting nonsense variants or the correction of folding defects caused by amino acid substitutions. Overall, these approaches have shown the ability to rescue the expression and/or function of potentially therapeutic levels of coagulation factors in different disease models, thus supporting further studies in the future aimed at evaluating the clinical translatability of these new strategies.
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Affiliation(s)
- Dario Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
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Pousada G, Lupo V, Cástro-Sánchez S, Álvarez-Satta M, Sánchez-Monteagudo A, Baloira A, Espinós C, Valverde D. Molecular and functional characterization of the BMPR2 gene in Pulmonary Arterial Hypertension. Sci Rep 2017; 7:1923. [PMID: 28507310 PMCID: PMC5432510 DOI: 10.1038/s41598-017-02074-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 04/05/2017] [Indexed: 11/09/2022] Open
Abstract
Pulmonary arterial hypertension is a progressive disease that causes the obstruction of precapillary pulmonary arteries and a sustained increase in pulmonary vascular resistance. The aim was to analyze functionally the variants found in the BMPR2 gene and to establish a genotype-phenotype correlation. mRNA expression studies were performed using pSPL3 vector, studies of subcellular localization were performed using pEGFP-N1 vector and luciferase assays were performed using pGL3-Basic vector. We have identified 30 variants in the BMPR2 gene in 27 of 55 patients. In 16 patients we detected pathogenic mutations. Minigene assays revealed that 6 variants (synonymous, missense) result in splicing defect. By immunofluorescence assay, we observed that 4 mutations affect the protein localization. Finally, 4 mutations located in the 5'UTR region showed a decreased transcriptional activity in luciferase assays. Genotype-phenotype correlation, revealed that patients with pathogenic mutations have a more severe phenotype (sPaP p = 0.042, 6MWT p = 0.041), a lower age at diagnosis (p = 0.040) and seemed to have worse response to phosphodiesterase-5-inhibitors (p = 0.010). Our study confirms that in vitro expression analysis is a suitable approach in order to investigate the phenotypic consequences of the nucleotide variants, especially in cases where the involved genes have a pattern of expression in tissues of difficult access.
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Affiliation(s)
- Guillermo Pousada
- Dep. Biochemistry, Genetics and Immunology. Faculty of Biology, University of Vigo, As Lagoas Marcosende S/N, 36310, Vigo, Spain.,Grupo de Investigación Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Vincenzo Lupo
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), 46012, Valencia, Spain
| | - Sheila Cástro-Sánchez
- Dep. Biochemistry, Genetics and Immunology. Faculty of Biology, University of Vigo, As Lagoas Marcosende S/N, 36310, Vigo, Spain.,Grupo de Investigación Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - María Álvarez-Satta
- Dep. Biochemistry, Genetics and Immunology. Faculty of Biology, University of Vigo, As Lagoas Marcosende S/N, 36310, Vigo, Spain.,Grupo de Investigación Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Ana Sánchez-Monteagudo
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), 46012, Valencia, Spain
| | - Adolfo Baloira
- Neumology Service, Complexo Hospitalario Universitario de Pontevedra, 36071, Pontevedra, Spain
| | - Carmen Espinós
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), 46012, Valencia, Spain
| | - Diana Valverde
- Dep. Biochemistry, Genetics and Immunology. Faculty of Biology, University of Vigo, As Lagoas Marcosende S/N, 36310, Vigo, Spain. .,Grupo de Investigación Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain.
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15
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Palagano E, Susani L, Menale C, Ramenghi U, Berger M, Uva P, Oppo M, Vezzoni P, Villa A, Sobacchi C. Synonymous Mutations Add a Layer of Complexity in the Diagnosis of Human Osteopetrosis. J Bone Miner Res 2017; 32:99-105. [PMID: 27468155 DOI: 10.1002/jbmr.2929] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/25/2016] [Accepted: 07/27/2016] [Indexed: 11/08/2022]
Abstract
Autosomal recessive osteopetroses (AROs) are rare, genetically heterogeneous skeletal diseases with increased bone density that are often lethal if left untreated. A precise molecular classification is relevant for the patient's management, because in some subgroups hematopoietic stem cell transplantation (HSCT), which is the only curative therapy, is contraindicated. In two unrelated ARO patients, the molecular analysis revealed the presence of a synonymous variant in known ARO genes, namely in the TCIRG1 gene in one patient and in the CLCN7 in the other patient, predicted to impact on the splicing process. In the latter case, sequencing of the transcript confirmed the splicing defect, whereas in the former, for whom an RNA sample was not available, the defect was reconstructed in vitro by the minigene technology. These results strongly suggest that these synonymous changes were responsible for the disease in our patients. Our findings are novel with respect to ARO and add to the few reports in literature dealing with different diseases, underlining the importance of cDNA analysis for the correct assessment of exonic changes, even when exome sequencing is performed. In particular, we highlight the possibility that at least in some cases ARO is due to synonymous changes, erroneously considered clinically silent, in the genes already described in literature, and suggest carefully reevaluating the sequencing results of these genes when mutations are not found at a first analysis. In addition, with respect to the CLCN7 gene, we suggest that synonymous variants might also contribute to the large spectrum of severity typical of CLCN7-dependent osteopetrosis through more subtle, but not negligible, effects on protein availability and functionality. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Eleonora Palagano
- Humanitas Clinical and Research Institute, Rozzano, Italy.,Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy
| | - Lucia Susani
- Humanitas Clinical and Research Institute, Rozzano, Italy.,National Research Council-Institute of Genetics and Biomedical Research (CNR-IRGB), Milan Unit, Milan, Italy
| | - Ciro Menale
- Humanitas Clinical and Research Institute, Rozzano, Italy.,National Research Council-Institute of Genetics and Biomedical Research (CNR-IRGB), Milan Unit, Milan, Italy
| | - Ugo Ramenghi
- Department of Public Health and Pediatric Sciences, University of Turin, Turin, Italy
| | - Massimo Berger
- Pediatric Onco-Hematology and Stem Cell Transplant Division, Regina Margherita Children Hospital, City of Health and Science, Turin, Italy
| | - Paolo Uva
- CRS4, Science and Technology Park Polaris, Pula, Italy
| | - Manuela Oppo
- CRS4, Science and Technology Park Polaris, Pula, Italy.,Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Paolo Vezzoni
- Humanitas Clinical and Research Institute, Rozzano, Italy.,National Research Council-Institute of Genetics and Biomedical Research (CNR-IRGB), Milan Unit, Milan, Italy
| | - Anna Villa
- Humanitas Clinical and Research Institute, Rozzano, Italy.,National Research Council-Institute of Genetics and Biomedical Research (CNR-IRGB), Milan Unit, Milan, Italy
| | - Cristina Sobacchi
- Humanitas Clinical and Research Institute, Rozzano, Italy.,National Research Council-Institute of Genetics and Biomedical Research (CNR-IRGB), Milan Unit, Milan, Italy
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16
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Nuzzo F, Beshlawi I, Wali Y, Castoldi E. High incidence of intracranial bleeding in factor V-deficient patients with homozygous F5 splicing mutations. Br J Haematol 2016; 179:163-166. [PMID: 27351627 DOI: 10.1111/bjh.14195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Francesca Nuzzo
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Ismail Beshlawi
- Child Health Department, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman.,Queen's Medical Centre, Nottingham University Hospitals' NHS Trust, Nottingham, UK
| | - Yasser Wali
- Child Health Department, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman.,Alexandria University Children's Hospital, Alexandria, Egypt
| | - Elisabetta Castoldi
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
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