1
|
Walne A, Tummala H, Ellison A, Cardoso S, Sidhu J, Sciuccati G, Vulliamy T, Dokal I. Expanding the phenotypic and genetic spectrum of radioulnar synostosis associated hematological disease. Haematologica 2018. [PMID: 29519864 DOI: 10.3324/haematol.2017.183855] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Amanda Walne
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| | - Hemanth Tummala
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| | - Alicia Ellison
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| | - Shirleny Cardoso
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| | - Jasmin Sidhu
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| | - Gabriela Sciuccati
- Sercico de Hematologia y Oncologia, Hospital de Pediatria "Prof. Dr. J.P. Garrahan", Buenos Aires, Argentina
| | - Tom Vulliamy
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| | - Inderjeet Dokal
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Barts NHS Trust, UK
| |
Collapse
|
2
|
Kumar R, Kahr WHA. Congenital thrombocytopenia: clinical manifestations, laboratory abnormalities, and molecular defects of a heterogeneous group of conditions. Hematol Oncol Clin North Am 2013; 27:465-94. [PMID: 23714308 DOI: 10.1016/j.hoc.2013.02.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Once considered exceptionally rare, congenital thrombocytopenias are increasingly recognized as a heterogeneous group of disorders characterized by a reduction in platelet number and a bleeding tendency that may range from very mild to life threatening. Although some of these disorders affect only megakaryocytes and platelets, others involve different cell types and may result in characteristic phenotypic abnormalities. This review elaborates the clinical presentation and laboratory manifestations of common congenital thrombocytopenias in addition to exploring our understanding of the molecular basis of these disorders and therapeutic interventions available.
Collapse
Affiliation(s)
- Riten Kumar
- Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | | |
Collapse
|
3
|
A neonate with congenital amegakaryocytic thrombocytopenia associated with a chromosomal microdeletion at 21q22.11 including the gene RUNX1. J Perinatol 2013; 33:242-4. [PMID: 23443295 DOI: 10.1038/jp.2012.53] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We observed a neonate who had severe thrombocytopenia wherein evaluations for neonatal immune-mediated thrombocytopenia and congenital infections were negative, and the marrow findings were consistent with congenital amegakaryocytic thrombocytopenia (CAMT). A genomic microarray identified a microdeletion at 21q22.11 including the gene RUNX1. Two somewhat similar cases were recently reported, but with multiple congenital anomalies that are not present in our case. We propose that a 21q22 deletion resulting in RUNX1 haploinsufficiency can produce a phenotype similar to CAMT with various associated anomalies depending on which adjacent genes are absent or disrupted.
Collapse
|
4
|
Christensen RD, Yaish HM, Leon EL, Sola-Visner MC, Agrawal PB. A de novo T73I mutation in PTPN11 in a neonate with severe and prolonged congenital thrombocytopenia and Noonan syndrome. Neonatology 2013; 104:1-5. [PMID: 23446178 DOI: 10.1159/000346375] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/03/2012] [Indexed: 11/19/2022]
Abstract
We observed a neonate with severe congenital thrombocytopenia and features of Noonan syndrome where evaluations were negative for immune-mediated thrombocytopenia, congenital infections, and Fanconi anemia. The marrow findings and a significantly elevated plasma thrombopoietin (Tpo) level were consistent with congenital amegakaryocytic thrombocytopenia; we sought a genetic mutation that could explain this phenotype. No mutations were identified in c-MPL (the Tpo receptor gene). Microarray analysis of peripheral blood did not reveal an abnormality. DNA sequencing of the PTPN11 gene showed a heterozygous C>T nucleotide substitution in exon 3 (c.218C>T) predicted to result in a threonine-to-isoleucine change at residue 73 (T73I). A 6-week trial of eltrombopag (an agonist of the Tpo receptor) failed to increase the platelet count. We propose this specific PTPN11 mutation results in abnormalities of the protein product SHP-2, which, because of its role in signal transduction, results in severe congenital thrombocytopenia refractory to c-MPL agonists.
Collapse
Affiliation(s)
- Robert D Christensen
- Department of Women and Newborns, Intermountain Healthcare,University of Utah School of Medicine, Salt Lake City, Utah 84403, USA.
| | | | | | | | | |
Collapse
|
5
|
Ferrer-Marin F, Liu ZJ, Gutti R, Sola-Visner M. Neonatal thrombocytopenia and megakaryocytopoiesis. Semin Hematol 2011; 47:281-8. [PMID: 20620440 DOI: 10.1053/j.seminhematol.2010.04.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Thrombocytopenia is common among sick neonates, affecting 20% to 35% of all patients admitted to the neonatal intensive care unit (NICU). While most cases of neonatal thrombocytopenia are mild or moderate and resolve within 7 to 14 days with appropriate therapy, 2.5% to 5% of NICU patients develop severe thrombocytopenia, sometimes lasting for several weeks and requiring >20 platelet transfusions. The availability of thrombopoietic agents offers the possibility of decreasing the number of platelet transfusions and potentially improving the outcomes of these infants. However, adding thrombopoietin (TPO) mimetics to the therapeutic armamentarium of neonatologists will require careful attention to the substantial developmental differences between neonates and adults in the process of megakaryocytopoiesis and in their responses to TPO. Taken together, the available data suggest that TPO mimetics will stimulate platelet production in neonates, but might do so through different mechanisms and at different doses than those established for adults. In addition, the specific groups of thrombocytopenic neonates most likely to benefit from therapy with TPO mimetics need to be defined, and the potential nonhematological effects of these agents on the developing organism need to be considered. This review summarizes our current understanding of neonatal megakaryocytopoiesis, and examines in detail the developmental factors relevant to the potential use of TPO mimetics in neonates.
Collapse
Affiliation(s)
- Francisca Ferrer-Marin
- Division of Newborn Medicine, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
6
|
Ballmaier M, Germeshausen M. Advances in the understanding of congenital amegakaryocytic thrombocytopenia. Br J Haematol 2009; 146:3-16. [PMID: 19388932 DOI: 10.1111/j.1365-2141.2009.07706.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Congenital amegakaryocytic thrombocytopenia (MIM #604498) is an extremely rare inherited bone marrow failure syndrome, usually presenting as a severe thrombocytopenia at birth due to ineffective megakaryocytopoiesis and no characteristic physical anomalies. Usually the isolated thrombocytopenia progresses to pancytopenia during the first years of life. The only curative therapy to date is haematopoietic stem cell transplantation. Most of the cases of congenital amegakaryocytic thrombocytopenia are caused by defective expression or function of the thrombopoietin receptor due to homozygous or compound heterozygous mutations in the gene MPL. The essential roles of thrombopoietin as a lineage specific regulator of platelet production and as a regulator of haematopoietic stem cell function are reflected in the haematological defects seen in affected individuals.
Collapse
Affiliation(s)
- Matthias Ballmaier
- Department of Paediatric Haematology and Oncology, Hannover Medical School, Hannover, Germany.
| | | |
Collapse
|
7
|
Abstract
Neonatal alloimmune thrombocytopenia (NAIT) occurs when maternal antibodies are directed against antigens on fetal and paternal but not maternal platelets. Most cases of NAIT arise when platelets of the father (and the fetus) express the human platelet antigen (HPA)1a and the mother's platelets expresses HPA-1b. A female patient presented with congenital severe thrombocytopenia and received 4 platelet transfusions, on days 2, 7, 16, and 28. This appeared to be a case of NAIT; however, extensive serologic evaluation by 2 reference laboratories failed to reveal the offending platelet antigen. Consistent with NAIT, the condition resolved by 6 weeks of age. By patient day of life 42, the platelet count had increased without additional need for transfusions, and by 16 weeks, the patient had a completely normal platelet count of 437,000/microL. The patient's platelet count remains normal at a 2-year follow-up. This case is reported as an instructive atypical case of NAIT, in which the relevant platelet antigen could not be identified.
Collapse
Affiliation(s)
- Cindy K Barney
- Neonatal Intensive Care Unit, McKay-Dee Hospital, Intermountain Health Care, 4401 Harrison Boulevard, Ogden, UT 84403, USA.
| | | | | |
Collapse
|
8
|
Geddis AE. Inherited Thrombocytopenia: Congenital Amegakaryocytic Thrombocytopenia and Thrombocytopenia With Absent Radii. Semin Hematol 2006; 43:196-203. [PMID: 16822462 DOI: 10.1053/j.seminhematol.2006.04.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Thrombocytopenia in the newborn period can signify an inherited platelet disorder. Congenital amegakaryocytic thrombocytopenia (CAMT) and thrombocytopenia with absent radii (TAR) share features of isolated thrombocytopenia, reduced or absent marrow megakaryocytes, impaired responsiveness to thrombopoietin (TPO), and high plasma TPO levels. These disorders are most readily distinguished from each other by the finding of radial aplasia in TAR and the presence of c-MPL mutations in CAMT. In addition, their long-term outcomes are strikingly different: the development of trilineage marrow failure in CAMT in contrast to the general improvement of thrombocytopenia in TAR. The differential diagnosis for CAMT and TAR also includes other congenital disorders in which thrombocytopenia and radial abnormalities can be seen. In this article we will review our molecular and clinical understanding of these two inherited disorders of amegakaryocytosis.
Collapse
Affiliation(s)
- Amy E Geddis
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
9
|
King S, Germeshausen M, Strauss G, Welte K, Ballmaier M. Congenital amegakaryocytic thrombocytopenia: a retrospective clinical analysis of 20 patients. Br J Haematol 2006; 131:636-44. [PMID: 16351641 DOI: 10.1111/j.1365-2141.2005.05819.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare bone marrow failure syndrome characterised by isolated thrombocytopenia because of ineffective megakaryocytopoiesis at birth. In the last 10 years, we collected data from 20 patients diagnosed with CAMT based on a severe thrombocytopenia since birth and absent or markedly decreased numbers of megakaryocytes in the bone marrow. Fanconi's anaemia and thrombocytopenia absent radii syndrome were ruled out for all patients. We retrospectively compared the clinical courses, laboratory findings and treatment outcome. Development of pancytopenia was observed in 14 of the patients, only one patient presented with an isolated thrombocytopenia over a period of over 14 years. One boy died from bleeding complications. We defined two groups of patients according to the course of platelet counts during the first year of life, which also differed in the course of development of pancytopenia. Physical anomalies in addition to haematopoiesis were found in a number of patients: two children presented with cardiac defects, six with growth abnormalities, and four with retardation of psychomotor development. Fifteen patients were treated with haematopoietic stem cell transplantation, four of whom died of transplantation-related events.
Collapse
Affiliation(s)
- Stephanie King
- Department of Paediatric Haematology and Oncology, Hannover Medical School, Hannover, Germany
| | | | | | | | | |
Collapse
|