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Rivas VN, Tan AWK, Shaverdian M, Nguyen NP, Wouters JR, Stern JA, Li RHL. A novel ITGA2B double cytosine frameshift variant (c.1986_1987insCC) leads to Glanzmann's thrombasthenia in a cat. J Vet Intern Med 2024; 38:1408-1417. [PMID: 38426552 PMCID: PMC11099703 DOI: 10.1111/jvim.17030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/16/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND Glanzmann's thrombasthenia (GT) is a congenital platelet disorder affecting approximately 1:1 000 000 people globally and characterized by impaired platelet aggregation and clot retraction. Autosomal recessive, loss-of-function, variants in ITGA2B or ITGB3 of the αIIbβ3 receptor cause the disease in humans. A cat affected by Glanzmann's and macrothrombocytopenia was presented to the UC Davis VMTH. HYPOTHESIS/OBJECTIVES Severe thrombopathia in this cat has an underlying genetic etiology. ANIMALS A single affected patient, 2 age-matched clinically healthy controls, and a geriatric population (n = 20) of normal cats. METHODS Physical examination and clinical pathology tests were performed on the patient. Flow cytometry and platelet aggregometry analyses for patient phenotyping were performed. Patient and validation cohort gDNA samples were extracted for Sanger sequencing of a previously identified ITGA2B (c.1986delC) variant. Reverse transcriptase PCR was performed on patient and healthy control PRP samples to verify ITGA2B variant consequence. RESULTS A novel c.1986_1987insCC autosomal recessive variant in ITGA2B was identified. This variant was absent in a population of 194 unrelated cats spanning 44 different breeds. Complete loss of ITGA2B transcript and protein expression was verified by RT-PCR and flow cytometry, explaining the underlying etiology of GT, and likely macrothrombocytopenia, in this cat. CONCLUSIONS AND CLINICAL IMPORTANCE This study emphasizes the role of precision medicine in cardiovascular disease of cats and identified yet another variant that may be of utility for screening in the feline population. This study provides a small-volume, standardized, successful protocol for adequate platelet RNA isolation and subsequent molecular assessment of gene expression in cats.
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Affiliation(s)
- Victor N. Rivas
- Department of Medicine and Epidemiology, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Avalene W. K. Tan
- Department of Surgical and Radiological Sciences, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
| | - Meg Shaverdian
- Department of Surgical and Radiological Sciences, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
| | - Nghi P. Nguyen
- Department of Surgical and Radiological Sciences, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
| | - Jalena R. Wouters
- Department of Medicine and Epidemiology, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
| | - Joshua A. Stern
- Department of Medicine and Epidemiology, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Ronald H. L. Li
- Department of Clinical Sciences, College of Veterinary MedicineNorth Carolina State UniversityRaleighNorth CarolinaUSA
- Department of Surgical and Radiological Sciences, School of Veterinary MedicineUniversity of California‐DavisDavisCaliforniaUSA
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2
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Li M, Peng L, Wang Z, Liu L, Cao M, Cui J, Wu F, Yang J. Roles of the cytoskeleton in human diseases. Mol Biol Rep 2023; 50:2847-2856. [PMID: 36609753 DOI: 10.1007/s11033-022-08025-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 10/12/2022] [Indexed: 01/08/2023]
Abstract
Recently, researches have revealed the key roles of the cytoskeleton in the occurrence and development of multiple diseases, suggesting that targeting the cytoskeleton is a viable approach for treating numerous refractory diseases. The cytoskeleton is a highly structured and complex network composed of actin filaments, microtubules, and intermediate filaments. In normal cells, these three cytoskeleton components are highly integrated and coordinated. However, the cytoskeleton undergoes drastic remodeling in cytoskeleton-related diseases, causing changes in cell polarity, affecting the cell cycle, leading to senescent diseases, and influencing cell migration to accelerate cancer metastasis. Additionally, mutations or abnormalities in cytoskeletal proteins and their related proteins are closely associated with several congenital diseases. Therefore, this review summarizes the roles of the cytoskeleton in cytoskeleton-related diseases as well as its potential roles in disease treatment to provide insights regarding the physiological functions and pathological roles of the cytoskeleton.
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Affiliation(s)
- Mengxin Li
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China
| | - Li Peng
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, China
| | - Zhenming Wang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China
| | - Lijia Liu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China
| | - Mengjiao Cao
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China
| | - Jingyao Cui
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China
| | - Fanzi Wu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China
| | - Jing Yang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Department of Cardiology and Endodontics, West China Hospital of Stomatology, Sichuan University, 610021, Chengdu, China.
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3
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Kimmerlin Q, Strassel C, Eckly A, Lanza F. The tubulin code in platelet biogenesis. Semin Cell Dev Biol 2022; 137:63-73. [PMID: 35148939 DOI: 10.1016/j.semcdb.2022.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 01/12/2022] [Accepted: 01/31/2022] [Indexed: 11/28/2022]
Abstract
Blood platelets are small non-nucleated cellular fragments that prevent and stop hemorrhages. They are produced in the bone marrow by megakaryocytes through megakaryopoiesis. This intricate process involves profound microtubule rearrangements culminating in the formation of a unique circular sub-membranous microtubule array, the marginal band, which supports the typical disc-shaped morphology of platelets. Mechanistically, these processes are thought to be controlled by a specific tubulin code. In this review, we summarize the current knowledge on the key isotypes, notably β1-, α4A- and α8-tubulin, and putative post-translational modifications, involved in platelet and marginal band formation. Additionally, we provide a provisional list of microtubule-associated proteins (MAPs) involved in these processes and a survey of tubulin variants identified in patients presenting defective platelet production. A comprehensive characterization of the platelet tubulin code and the identification of essential MAPs may be expected in the near future to shed new light on a very specialized microtubule assembly process with applications in platelet diseases and transfusion.
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Affiliation(s)
- Quentin Kimmerlin
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France.
| | - Catherine Strassel
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France.
| | - Anita Eckly
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France.
| | - François Lanza
- Université de Strasbourg, INSERM, EFS Grand-Est, BPPS UMR-S1255, FMTS, Strasbourg, France.
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4
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Kimmerlin Q, Dupuis A, Bodakuntla S, Weber C, Heim V, Henriot V, Moog S, Eckly A, Guéguen P, Ferec C, Gachet C, Janke C, Lanza F. Mutations in the most divergent α-tubulin isotype, α8-tubulin, cause defective platelet biogenesis. J Thromb Haemost 2022; 20:461-469. [PMID: 34704371 DOI: 10.1111/jth.15573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/12/2021] [Accepted: 10/25/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND In the panel of genes commonly associated with inherited macrothrombocytopenia, an important fraction encodes key cytoskeletal proteins such as tubulin isotypes, the building blocks of microtubules. Macrothrombocytopenia-causing mutations have been identified in the TUBB1 and TUBA4A genes, emphasizing their importance in the formation of platelets and their marginal band, a unique microtubule ring-like structure that supports the platelet typical disc-shaped morphology. This raised the hypothesis that other tubulin isotypes normally expressed in platelets could play a similar role in their formation. OBJECTIVES To assess whether tubulin isotype genes other than TUBA4A and TUBB1 could be implicated in inherited macrothrombocytopenia. METHODS We used high throughput sequencing to screen a cohort of 448 French blood donors with mild thrombocytopenia for mutations in a panel of selected genes known or suspected to be involved in platelet biogenesis. RESULTS We identified six distinct novel mutations in TUBA8, which encodes the most-divergent α-tubulin, as the causative determinant of macrothrombocytopenia and platelet marginal band defects. Functionally, all TUBA8 mutations were found to fully or partially inhibit the incorporation of the mutated α8-tubulin in the microtubule network. CONCLUSION This study provides strong support for a key role of multiple tubulin genes in platelet biogenesis by discovering variants in a tubulin gene that was previously not known to be important for platelets.
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Affiliation(s)
- Quentin Kimmerlin
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Arnaud Dupuis
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Satish Bodakuntla
- Institut Curie, CNRS UMR3348, Paris-Sciences-et-Lettres Research University, Orsay, France
- CNRS UMR3348, Université Paris Sud, Université Paris-Saclay, Orsay, France
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Claire Weber
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Véronique Heim
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Véronique Henriot
- Institut Curie, CNRS UMR3348, Paris-Sciences-et-Lettres Research University, Orsay, France
- CNRS UMR3348, Université Paris Sud, Université Paris-Saclay, Orsay, France
| | - Sylvie Moog
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Anita Eckly
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Paul Guéguen
- Laboratoire de génétique moléculaire et d'histocompatibilité, Centre Hospitalier Régional et Universitaire Morvan, INSERM U1078, EFS Bretagne, Brest, France
| | - Claude Ferec
- Laboratoire de génétique moléculaire et d'histocompatibilité, Centre Hospitalier Régional et Universitaire Morvan, INSERM U1078, EFS Bretagne, Brest, France
| | - Christian Gachet
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Carsten Janke
- Institut Curie, CNRS UMR3348, Paris-Sciences-et-Lettres Research University, Orsay, France
- CNRS UMR3348, Université Paris Sud, Université Paris-Saclay, Orsay, France
| | - François Lanza
- Institut National de la Santé et de la Recherche Médicale, Etablissement Français du Sang Grand Est, Unité Mixte de Recherche-S 1255, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
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5
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Boeckelmann D, Glonnegger H, Sandrock-Lang K, Zieger B. Pathogenic Aspects of Inherited Platelet Disorders. Hamostaseologie 2021; 41:460-468. [PMID: 34942659 DOI: 10.1055/a-1665-6249] [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
Inherited platelet disorders (IPDs) constitute a large heterogeneous group of rare bleeding disorders. These are classified into: (1) quantitative defects, (2) qualitative disorders, or (3) altered platelet production rate disorders or increased platelet turnover. Classically, IPD diagnostic is based on clinical phenotype characterization, comprehensive laboratory analyses (platelet function analysis), and, in former times, candidate gene sequencing. Today, molecular genetic analysis is performed using next-generation sequencing, mostly by targeting enrichment of a gene panel or by whole-exome sequencing. Still, the biochemical and molecular genetic characterization of patients with congenital thrombocytopathias/thrombocytopenia is essential, since postoperative or posttraumatic bleeding often occurs due to undiagnosed platelet defects. Depending upon the kind of surgery or trauma, this bleeding may be life-threatening, e.g., after tonsillectomy or in brain surgery. Undiagnosed platelet defects may lead to additional surgery, hysterectomy, pulmonary bleeding, and even resuscitation. In addition, these increased bleeding symptoms can lead to wound healing problems. Only specialized laboratories can perform the special platelet function analyses (aggregometry, flow cytometry, or immunofluorescent microscopy of the platelets); therefore, many IPDs are still undetected.
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Affiliation(s)
- Doris Boeckelmann
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center - University of Freiburg, Freiburg, Germany
| | - Hannah Glonnegger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center - University of Freiburg, Freiburg, Germany
| | - Kirstin Sandrock-Lang
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center - University of Freiburg, Freiburg, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center - University of Freiburg, Freiburg, Germany
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6
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Nurden A. Profiling the Genetic and Molecular Characteristics of Glanzmann Thrombasthenia: Can It Guide Current and Future Therapies? J Blood Med 2021; 12:581-599. [PMID: 34267570 PMCID: PMC8275161 DOI: 10.2147/jbm.s273053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/16/2021] [Indexed: 12/15/2022] Open
Abstract
Glanzmann thrombasthenia (GT) is the most widely studied inherited disease of platelet function. Platelets fail to aggregate due to a defect in platelet-to-platelet attachment. The hemostatic plug fails to form and a moderate to severe bleeding diathesis results. Classically of autosomal recessive inheritance, GT is caused by defects within the ITGA2B and ITGB3 genes that encode the αIIbβ3 integrin expressed at high density on the platelet surface and also in intracellular pools. Activated αIIbβ3 acts as a receptor for fibrinogen and other adhesive proteins that hold platelets together in a thrombus. Over 50 years of careful clinical and biological investigation have provided important advances that have improved not only the quality of life of the patients but which have also contributed to an understanding of how αIIbβ3 functions. Despite major improvements in our knowledge of GT and its genetic causes, extensive biological and clinical variability with respect to the severity and intensity of bleeding remains poorly understood. I now scan the repertoire of ITGA2B and ITGB3 gene defects and highlight the wide genetic and biological heterogeneity within the type II and variant subgroups especially with regard to bleeding, clot retraction, the internal platelet Fg storage pool and the nature of the mutations causing the disease. I underline the continued importance of gene profiling and biological studies and emphasize the multifactorial etiology of the clinical expression of the disease. This is done in a manner to provide guidelines for future studies and future treatments of a disease that has not only aided research on rare diseases but also contributed to advances in antithrombotic therapy.
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Affiliation(s)
- Alan Nurden
- Institut Hospitalo-Universitaire LIRYC, Pessac, France
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7
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Mbiandjeu S, Balduini A, Malara A. Megakaryocyte Cytoskeletal Proteins in Platelet Biogenesis and Diseases. Thromb Haemost 2021; 122:666-678. [PMID: 34218430 DOI: 10.1055/s-0041-1731717] [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]
Abstract
Thrombopoiesis governs the formation of blood platelets in bone marrow by converting megakaryocytes into long, branched proplatelets on which individual platelets are assembled. The megakaryocyte cytoskeleton responds to multiple microenvironmental cues, including chemical and mechanical stimuli, sustaining the platelet shedding. During the megakaryocyte's life cycle, cytoskeletal networks organize cell shape and content, connect them physically and biochemically to the bone marrow vascular niche, and enable the release of platelets into the bloodstream. While the basic building blocks of the cytoskeleton have been studied extensively, new sets of cytoskeleton regulators have emerged as critical components of the dynamic protein network that supports platelet production. Understanding how the interaction of individual molecules of the cytoskeleton governs megakaryocyte behavior is essential to improve knowledge of platelet biogenesis and develop new therapeutic strategies for inherited thrombocytopenias caused by alterations in the cytoskeletal genes.
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Affiliation(s)
- Serge Mbiandjeu
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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8
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Nurden P, Stritt S, Favier R, Nurden AT. Inherited platelet diseases with normal platelet count: phenotypes, genotypes and diagnostic strategy. Haematologica 2021; 106:337-350. [PMID: 33147934 PMCID: PMC7849565 DOI: 10.3324/haematol.2020.248153] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 08/12/2020] [Indexed: 12/16/2022] Open
Abstract
Inherited platelet disorders resulting from platelet function defects and a normal platelet count cause a moderate or severe bleeding diathesis. Since the description of Glanzmann thrombasthenia resulting from defects of ITGA2B and ITGB3, new inherited platelet disorders have been discovered, facilitated by the use of high throughput sequencing and genomic analyses. Defects of RASGRP2 and FERMT3 responsible for severe bleeding syndromes and integrin activation have illustrated the critical role of signaling molecules. Important are mutations of P2RY12 encoding the major ADP receptor causal for an inherited platelet disorder with inheritance characteristics that depend on the variant identified. Interestingly, variants of GP6 encoding the major subunit of the collagen receptor GPVI/FcRγ associate only with mild bleeding. The numbers of genes involved in dense granule defects including Hermansky-Pudlak and Chediak Higashi syndromes continue to progress and are updated. The ANO6 gene encoding a Ca2+-activated ion channel required for phospholipid scrambling is responsible for the rare Scott syndrome and decreased procoagulant activity. A novel EPHB2 defect in a familial bleeding syndrome demonstrates a role for this tyrosine kinase receptor independent of the classical model of its interaction with ephrins. Such advances highlight the large diversity of variants affecting platelet function but not their production, despite the difficulties in establishing a clear phenotype when few families are affected. They have provided insights into essential pathways of platelet function and have been at the origin of new and improved therapies for ischemic disease. Nevertheless, many patients remain without a diagnosis and requiring new strategies that are now discussed.
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Affiliation(s)
| | - Simon Stritt
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala
| | - Remi Favier
- French National Reference Center for Inherited Platelet Disorders, Armand Trousseau Hospital, Assistance Publique-Hôpitaux de Paris, Paris
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9
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Hou Y, Shao L, Zhou H, Liu Y, Fisk DG, Spiteri E, Zehnder JL, Peng J, Zhang BM, Hou M. Identification of a pathogenic TUBB1 variant in a Chinese family with congenital macrothrombocytopenia through whole genome sequencing. Platelets 2021; 32:1108-1112. [PMID: 33400601 DOI: 10.1080/09537104.2020.1869714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Congenital macrothrombocytopenia is a genetically heterogeneous group of rare disorders. We herein report a large Chinese family presented with phenotypic variability involving thrombocytopenia and/or giant platelets. Whole genome sequencing (WGS) of the proband and one of his affected brothers identified a potentially pathogenic c.952 C > T heterozygous variant in the TUBB1 gene. This p.R318W β1-tubulin variant was also identified in three additional siblings and five members of the next generation. These findings were consistent with an autosomal dominant inheritance with incomplete penetrance. Moreover, impaired platelet agglutination in response to ristocetin was detected in the patient's brother. Half of the family members harboring the p.R318W mutation displayed significantly decreased external release of p-selectin by stimulated platelets. The p.R318W β1-tubulin mutation was identified for the first time in a Chinese family with congenital macrothrombocytopenia using WGS as an unbiased sequencing approach. Affected individuals within the family demonstrated impaired platelet aggregation and/or release functions.
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Affiliation(s)
- Yu Hou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Linlin Shao
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Hai Zhou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Yanfeng Liu
- Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Dianna G Fisk
- Clinical Genomics Program, Stanford Health Care, Palo Alto, United States
| | - Elizabeth Spiteri
- Clinical Genomics Program, Stanford Health Care, Palo Alto, United States.,Department of Pathology, Stanford University School of Medicine, Palo Alto, United States
| | - James L Zehnder
- Department of Pathology, Stanford University School of Medicine, Palo Alto, United States
| | - Jun Peng
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Bing M Zhang
- Department of Pathology, Stanford University School of Medicine, Palo Alto, United States
| | - Ming Hou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Leading Research Group of Scientific Innovation, Department of Science and Technology of Shandong Province, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
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10
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Mekchay P, Ittiwut C, Ittiwut R, Akkawat B, Le Grand SM, Leela-adisorn N, Muanpetch S, Khovidhunkit W, Sosothikul D, Shotelersuk V, Suphapeetiporn K, Rojnuckarin P. Whole exome sequencing for diagnosis of hereditary thrombocytopenia. Medicine (Baltimore) 2020; 99:e23275. [PMID: 33217855 PMCID: PMC7676547 DOI: 10.1097/md.0000000000023275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Hereditary thrombocytopenia comprises extremely diverse diseases that are difficult to diagnose by phenotypes alone. Definite diagnoses are helpful for patient (Pt) management.To evaluate the role of whole exome sequencing (WES) in these Pts.Cases with unexplained long-standing thrombocytopenia and/or suggestive features were enrolled to the observational study. Bleeding scores and blood smear were evaluated. The variant pathogenicity from WES was determined by bioinformatics combined with all other information including platelet aggregometry, flow cytometry, and electron microscopy (EM).Seven unrelated Pts were recruited. All were female with macrothrombocytopenia. Clinical bleeding was presented in four Pts; extra-hematological features were minimal and family history was negative in every Pt. WES successfully identified all the 11 responsible mutant alleles; of these, four have never been previously reported. Pt 1 with GNE-related thrombocytopenia showed reduced lectin binding by flow cytometry, increased glycogen granules by EM and a novel homozygous mutation in GNE. Pts 2 and 3 had phenotypic diagnoses of Bernard Soulier syndrome and novel homozygous mutations in GP1BB and GP1BA, respectively. Pt 4 had impaired microtubule structures, concomitant delta storage pool disease by EM and a novel heterozygous TUBB1 mutation. Pt 5 had sitosterolemia showing platelets with reduced ristocetin responses and a dilated membrane system on EM with compound heterozygous ABCG5 mutations. Pts 6 and 7 had MYH9 disorders with heterozygous mutations in MYH9.This study substantiates the benefits of WES in identifying underlying mutations of macrothrombocytopenia, expands mutational spectra of four genes, and provides detailed clinical features for further phenotype-genotype correlations.
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Affiliation(s)
- Ponthip Mekchay
- Interdisciplinary Program of Biomedical Sciences, Graduate School, Chulalongkorn University
| | - Chupong Ittiwut
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society
| | - Rungnapa Ittiwut
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society
| | - Benjaporn Akkawat
- Division of Hematology, Department of Medicine, Faculty of Medicine, Chulalongkorn University
| | | | | | - Suwanna Muanpetch
- Hormonal and Metabolic Disorders Research Unit, Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University
| | - Weerapan Khovidhunkit
- Hormonal and Metabolic Disorders Research Unit, Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University
| | - Darintr Sosothikul
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Thailand
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society
| | - Kanya Suphapeetiporn
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society
| | - Ponlapat Rojnuckarin
- Division of Hematology, Department of Medicine, Faculty of Medicine, Chulalongkorn University
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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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Abstract
PURPOSE OF REVIEW To provide a comprehensive update on the current available methodologies and techniques for diagnosis of inherited platelet disorders (IPD). RECENT FINDINGS The contributions of many groups have resulted in the significant progress in the molecular diagnosis of IPD including the identification of many genes responsible for the various phenotypes. The widespread use and availability of next-generation sequencing has brought to the forefront ethical challenges associated with nontargeted sequencing as well as provided us with novel variants to functionally validate. These requirements have driven the development of novel tools for functional assessment of platelets, although none of the novel techniques beyond sequencing have yet taken clinical hold. SUMMARY Much work is ongoing on functional and molecular assessment of platelet disorders and the incorporation of combined assessments is likely to yield the highest diagnostic results.
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Berens C, Oldenburg J, Pötzsch B, Müller J. Glycophorin A-based exclusion of red blood cells for flow cytometric analysis of platelet glycoprotein expression in citrated whole blood. Clin Chem Lab Med 2020; 58:2081-2087. [PMID: 32598296 DOI: 10.1515/cclm-2020-0014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/31/2020] [Indexed: 11/15/2022]
Abstract
Objectives Analysis of platelet glycoprotein (GP) expression by flow cytometry is applied for diagnostic confirmation of GP-associated thrombocytopathies. While platelet-rich plasma may be used for distinct identification of target events, this strategy is not feasible for small sample volumes or for patients showing low platelet counts and/or giant platelets. However, also the use of whole blood (WB) is hampered by the difficulty to discriminate platelets from red blood cells (RBC) in such patients. To circumvent these limitations, we evaluated the feasibility of a RBC gating-out strategy. Methods In addition to platelet GPIb, GPIIa/IIIa, as well as P-selectin (CD62P), citrated whole blood (CWB) samples were stained for RBC-specific glycophorin A (CD235a). CD235a-negative platelet events were further discriminated by forward-/side-scatter characteristics and platelet GP expressions analyzed relative to that of a healthy control sample processed in parallel. Results Established reference intervals allowed for clear identification of decreased GPIIb/IIIa- or GPIb expression pattern in samples of patients with confirmed Glanzmann thrombasthenia or Bernard-Soulier syndrome, respectively. It could be shown that the analysis of 2,500 platelet events is sufficient for reliable GP expression analysis, rendering the proposed method applicable to samples with low platelet counts. Conclusions This study demonstrates the feasibility of CD235a-based exclusion of RBC for platelet GP expression analysis in CWB. In contrast to direct staining of platelet-specific antigens for target identification, this indirect gating out approach is generally applicable independent of any underlying platelet GP expression deficiency.
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Affiliation(s)
- Christina Berens
- Institute of Experimental Hematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Johannes Oldenburg
- Institute of Experimental Hematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Bernd Pötzsch
- Institute of Experimental Hematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Jens Müller
- Institute of Experimental Hematology and Transfusion Medicine, University of Bonn, Bonn, Germany
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Nurden AT, Nurden P. Inherited thrombocytopenias: history, advances and perspectives. Haematologica 2020; 105:2004-2019. [PMID: 32527953 PMCID: PMC7395261 DOI: 10.3324/haematol.2019.233197] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 05/08/2020] [Indexed: 12/11/2022] Open
Abstract
Over the last 100 years the role of platelets in hemostatic events and their production by megakaryocytes have gradually been defined. Progressively, thrombocytopenia was recognized as a cause of bleeding, first through an acquired immune disorder; then, since 1948, when Bernard-Soulier syndrome was first described, inherited thrombocytopenia became a fascinating example of Mendelian disease. The platelet count is often severely decreased and platelet size variable; associated platelet function defects frequently aggravate bleeding. Macrothrombocytopenia with variable proportions of enlarged platelets is common. The number of circulating platelets will depend on platelet production, consumption and lifespan. The bulk of macrothrombocytopenias arise from defects in megakaryopoiesis with causal variants in transcription factor genes giving rise to altered stem cell differentiation and changes in early megakaryocyte development and maturation. Genes encoding surface receptors, cytoskeletal and signaling proteins also feature prominently and Sanger sequencing associated with careful phenotyping has allowed their early classification. It quickly became apparent that many inherited thrombocytopenias are syndromic while others are linked to an increased risk of hematologic malignancies. In the last decade, the application of next-generation sequencing, including whole exome sequencing, and the use of gene platforms for rapid testing have greatly accelerated the discovery of causal genes and extended the list of variants in more common disorders. Genes linked to an increased platelet turnover and apoptosis have also been identified. The current challenges are now to use next-generation sequencing in first-step screening and to define bleeding risk and treatment better.
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Affiliation(s)
- Alan T Nurden
- Institut Hospitalo-Universitaire LIRYC, Pessac, France
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