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Bandini P, Borràs N, Berrueco R, Gassiot S, Martin-Fernandez L, Sarrate E, Comes N, Ramírez L, Hobeich C, Vidal F, Corrales I. Gaining Insights into Inherited Bleeding Disorders of Complex Etiology in Pediatric Patients: Whole-Exome Sequencing as First-Line Investigation Tool. Thromb Haemost 2023. [PMID: 38158197 DOI: 10.1055/s-0043-1778070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
INTRODUCTION Investigation of the molecular basis of inherited bleeding disorders (IBD) is mostly performed with gene panel sequencing. However, the continuous discovery of new related genes underlies the limitation of this approach. This study aimed to identify genetic variants responsible for IBD in pediatric patients using whole-exome sequencing (WES), and to provide a detailed description and reclassification of candidate variants. MATERIAL AND METHODS WES was performed for 18 pediatric patients, and variants were filtered using a first-line list of 290 genes. Variant prioritization was discussed in a multidisciplinary team based on genotype-phenotype correlation, and segregation studies were performed with available family members. RESULTS The study identified 22 candidate variants in 17 out of 18 patients (94%). Eleven patients had complete genotype-phenotype correlation, resulting in a diagnostic yield of 61%, 5 (28%) were classified as partially solved, and 2 (11%) remained unsolved. Variants were identified in platelet (ACTN1, ANKRD26, CYCS, GATA1, GFI1B, ITGA2, NBEAL2, RUNX1, SRC, TUBB1), bleeding (APOLD1), and coagulation (F7, F8, F11, VWF) genes. Notably, 9 out of 22 (41%) variants were previously unreported. Variant pathogenicity was assessed according to the American College of Medical Genetics and Genomics guidelines and reclassification of three variants based on family segregation evidence, resulting in the identification of 10 pathogenic or likely pathogenic variants, 6 variants of uncertain significance, and 6 benign or likely benign variants. CONCLUSION This study demonstrated the high potential of WES in identifying rare molecular defects causing IBD in pediatric patients, improving their management, prognosis, and treatment, particularly for patients at risk of malignancy and/or bleeding due to invasive procedures.
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Affiliation(s)
- Perla Bandini
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
| | - Nina Borràs
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
| | - Ruben Berrueco
- Servei d'Hematologia Pediàtrica, Hospital Sant Joan de Déu Barcelona, Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu de Barcelona (IRP-HSJD), Universitat de Barcelona, Barcelona, Spain
- Instituto Nacional de Investigación Biomédica en Enfermedades Raras (CIBER ER), Instituto de Salud Carlos III, Madrid, Spain
| | - Susanna Gassiot
- Servei de Diagnòstic de Laboratori, Hospital Sant Joan de Déu Barcelona, Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu de Barcelona (IRP-HSJD), Universitat de Barcelona, Barcelona, Spain
| | - Laura Martin-Fernandez
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
| | - Edurne Sarrate
- Servei de Diagnòstic de Laboratori, Hospital Sant Joan de Déu Barcelona, Institut de Recerca Pediàtrica, Hospital Sant Joan de Déu de Barcelona (IRP-HSJD), Universitat de Barcelona, Barcelona, Spain
| | - Natàlia Comes
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
| | - Lorena Ramírez
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
| | - Carlos Hobeich
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
| | - Francisco Vidal
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV). Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Irene Corrales
- Laboratori de Coagulopaties Congènites, Banc de Sang i Teixits, Barcelona, Spain
- Medicina Transfusional, Vall d'Hebron Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV). Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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Alesci RS, Hecking C, Racké B, Janssen D, Dempfle CE. Utility of ACMG classification to support interpretation of molecular genetic test results in patients with factor VII deficiency. Front Med (Lausanne) 2023; 10:1220813. [PMID: 37521340 PMCID: PMC10382174 DOI: 10.3389/fmed.2023.1220813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/16/2023] [Indexed: 08/01/2023] Open
Abstract
Background The American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) have introduced an internationally shared framework for variant classification in genetic disorders. FVII deficiency is a rare inherited autosomal recessive bleeding disorder with sparse data concerning ACMG classification. Methods To develop an approach which may improve the utility of molecular genetic test results, 129 patients with FVII deficiency were retrospectively assigned to six subgroups for exploratory analysis: F7 gene wildtype (group 1), ACMG 1 (benign variant) or ACMG 2 (likely benign variant), only (group 2), ACMG 3 (variant of uncertain significance) ± ACMG 1-2 heterozygous or not classified variant (group 3), ACMG 4 (likely pathogenic variant), or ACMG 5 (pathogenic variant) single heterozygous ± ACMG 1-3 single heterozygous (group 4), ACMG 4-5 homozygous or ≥2 ACMG 4-5 heterozygous or ≥1 ACMG 4-5 heterozygous plus either ACMG 1 c.1238G>A modifying variant homozygous or ≥2 ACMG 1-3 (group 5), FVII deficiency and another bleeding disorder (group 6). Results Eleven of 31 patients (35.5%) in group 5 had abnormal ISTH-BS (n = 7) and/or history of substitution with recombinant factor VIIa (n = 5) versus 4 of 80 patients (5.0%, n = 1 abnormal ISTH-BS, n = 3 substitution) in groups 1 (n = 2/22), 2 (n = 1/29), 3 (n = 0/9), and 4 (n = 1/20). Four of 18 patients (22.2%) with FVII deficiency and another bleeding disorder (group 6) had an abnormal ISTH-BS (n = 2) and/or history of substitution with recombinant factor VIIa (n = 3). Conclusion Patients with a homozygous ACMG 4-5 variant or with specific combinations of heterozygous ACMG 4-5 ± ACMG 1-3 variants exhibited a high-risk bleeding phenotype in contrast to the remaining patients without another bleeding disorder. This result may serve as a basis to develop a genotype/phenotype prediction model in future studies.
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Affiliation(s)
| | | | - Benjamin Racké
- Institute of Immunology and Genetics, Kaiserslautern, Germany
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Bourguignon A, Tasneem S, Hayward CP. Screening and diagnosis of inherited platelet disorders. Crit Rev Clin Lab Sci 2022; 59:405-444. [PMID: 35341454 DOI: 10.1080/10408363.2022.2049199] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inherited platelet disorders are important conditions that often manifest with bleeding. These disorders have heterogeneous underlying pathologies. Some are syndromic disorders with non-blood phenotypic features, and others are associated with an increased predisposition to developing myelodysplasia and leukemia. Platelet disorders can present with thrombocytopenia, defects in platelet function, or both. As the underlying pathogenesis of inherited thrombocytopenias and platelet function disorders are quite diverse, their evaluation requires a thorough clinical assessment and specialized diagnostic tests, that often challenge diagnostic laboratories. At present, many of the commonly encountered, non-syndromic platelet disorders do not have a defined molecular cause. Nonetheless, significant progress has been made over the past few decades to improve the diagnostic evaluation of inherited platelet disorders, from the assessment of the bleeding history to improved standardization of light transmission aggregometry, which remains a "gold standard" test of platelet function. Some platelet disorder test findings are highly predictive of a bleeding disorder and some show association to symptoms of prolonged bleeding, surgical bleeding, and wound healing problems. Multiple assays can be required to diagnose common and rare platelet disorders, each requiring control of preanalytical, analytical, and post-analytical variables. The laboratory investigations of platelet disorders include evaluations of platelet counts, size, and morphology by light microscopy; assessments for aggregation defects; tests for dense granule deficiency; analyses of granule constituents and their release; platelet protein analysis by immunofluorescent staining or flow cytometry; tests of platelet procoagulant function; evaluations of platelet ultrastructure; high-throughput sequencing and other molecular diagnostic tests. The focus of this article is to review current methods for the diagnostic assessment of platelet function, with a focus on contemporary, best diagnostic laboratory practices, and relationships between clinical and laboratory findings.
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Affiliation(s)
- Alex Bourguignon
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
| | - Subia Tasneem
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
| | - Catherine P Hayward
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada.,Department of Medicine, McMaster University, Hamilton, Canada
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Pezeshkpoor B, Oldenburg J, Pavlova A. Experiences in Routine Genetic Analysis of Hereditary Hemorrhagic, Thrombotic, and Platelet Disorders. Hamostaseologie 2022; 42:S5-S12. [PMID: 35226963 DOI: 10.1055/a-1726-4793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Hemostasis is a complex and tightly regulated system that attempts to maintain a homeostatic balance to permit normal blood flow, without bleeding or thrombosis. Hemostasis reflects the subtle balance between procoagulant and anticoagulant factors in the pathways of primary hemostasis, secondary hemostasis, and fibrinolysis. The major components in this interplay include the vascular endothelium, platelets, coagulation factors, and fibrinolytic factors. After vessel wall injury, the subendothelium is exposed to the blood stream, followed by rapid activation of platelets via collagen binding and von Willebrand factor-mediated platelet adhesion to the damaged vessel wall through platelet glycoprotein receptor Ib/IX/V. Activated platelets change their shape, release bioactive molecules from their granules, and expose negatively charged phospholipids on their surface. For a proper function of this process, an adequate number of functional platelets are required. Subsequently, a rapid generation of sufficient amounts of thrombin begins; followed by activation of the coagulation system and its coagulation factors (secondary hemostasis), generating fibrin that consolidates the platelet plug. To maintain equilibrium between coagulation and anticoagulation, the naturally occurring anticoagulants such as protein C, protein S, and antithrombin keep this process in balance. Deficiencies (inherited or acquired) at any level of this fine-tuned system result in pathologic bleedings or increased hypercoagulability states leading to thrombosis. This review will focus on genetic diagnosis of inherited bleeding, thrombotic, and platelet disorders, discussing strengths and limitations of existing diagnostic settings and genetic tools and highlight some important considerations necessary for clinical application.
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Affiliation(s)
- B Pezeshkpoor
- Institute of Experimental Hematology and Transfusion Medicine, University Hospital Bonn, Medical Faculty, University of Bonn, Bonn, Germany.,Center for Rare Diseases Bonn (ZSEB), University Clinic Bonn, Bonn, Germany
| | - J Oldenburg
- Institute of Experimental Hematology and Transfusion Medicine, University Hospital Bonn, Medical Faculty, University of Bonn, Bonn, Germany.,Center for Rare Diseases Bonn (ZSEB), University Clinic Bonn, Bonn, Germany
| | - A Pavlova
- Institute of Experimental Hematology and Transfusion Medicine, University Hospital Bonn, Medical Faculty, University of Bonn, Bonn, Germany.,Center for Rare Diseases Bonn (ZSEB), University Clinic Bonn, Bonn, Germany
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Zaninetti C, Wolff M, Greinacher A. Diagnosing Inherited Platelet Disorders: Modalities and Consequences. Hamostaseologie 2021; 41:475-488. [PMID: 34391210 DOI: 10.1055/a-1515-0813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Inherited platelet disorders (IPDs) are a group of rare conditions featured by reduced circulating platelets and/or impaired platelet function causing variable bleeding tendency. Additional hematological or non hematological features, which can be congenital or acquired, distinctively mark the clinical picture of a subgroup of patients. Recognizing an IPD is challenging, and diagnostic delay or mistakes are frequent. Despite the increasing availability of next-generation sequencing, a careful phenotyping of suspected patients-concerning the general clinical features, platelet morphology, and function-is still demanded. The cornerstones of IPD diagnosis are clinical evaluation, laboratory characterization, and genetic testing. Achieving a diagnosis of IPD is desirable for several reasons, including the possibility of tailored therapeutic strategies and individual follow-up programs. However, detailed investigations can also open complex scenarios raising ethical issues in case of IPDs predisposing to hematological malignancies. This review offers an overview of IPD diagnostic workup, from the interview with the proband to the molecular confirmation of the suspected disorder. The main implications of an IPD diagnosis are also discussed.
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Affiliation(s)
- Carlo Zaninetti
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany.,Department of Internal Medicine, University of Pavia, Pavia, Italy
| | - Martina Wolff
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Andreas Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
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Ver Donck F, Downes K, Freson K. Strengths and limitations of high-throughput sequencing for the diagnosis of inherited bleeding and platelet disorders. J Thromb Haemost 2020; 18:1839-1845. [PMID: 32521110 DOI: 10.1111/jth.14945] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/27/2020] [Accepted: 05/31/2020] [Indexed: 12/23/2022]
Abstract
Inherited bleeding and platelet disorders (BPD) are highly heterogeneous and their diagnosis involves a combination of clinical investigations, laboratory tests, and genetic screening. This review will outline some of the challenges that geneticists and experts in clinical hemostasis face when implementing high-throughput sequencing (HTS) for patient care. We will provide an overview of the strengths and limitations of the different HTS techniques that can be used to diagnose BPD. An HTS test is cost-efficient and expected to increase the diagnostic rate with a possibility to detect unexpected diagnoses and decrease the turnaround time to diagnose patients. On the other hand, technical shortcomings, variant interpretation difficulties, and ethical issues related to HTS for BPD will also be documented. Delivering a genetic diagnosis to patients is highly desirable to improve clinical management and allow family counseling, but making incorrect assumptions about variants and providing insufficient information to patients before initiating the test could be harmful. Data-sharing and improved HTS guidelines are essential to limit these major drawbacks of HTS.
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Affiliation(s)
- Fabienne Ver Donck
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Kate Downes
- East Midlands and East of England Genomics Laboratory Hub, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Kathleen Freson
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
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