Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The presence of the JAK2 V617F mutation is now part of clinical diagnostic algorithms, and JAK2 status is routinely assessed when BCR/ABL- chronic myeloproliferative neoplasms (MPNs) are suspected. The aim of this study was to evaluate performance of 3 screening and 1 quantitative method for JAK2 V617F detection. For the study, 43 samples (27 bone marrow aspirates and 16 peripheral blood samples) were selected. The screening assays were the JAK2 Activating Mutation Assay (InVivoScribe, San Diego, CA), JAK2 MutaScreen kit (Ipsogen, Luminy Biotech, Marseille, France), and a home-brew melting curve analysis method. Ipsogen's JAK2 MutaQuant assay was used for quantification of mutant and wild-type alleles. The limit of detection was 1% for the kit-based screening methods and 10% for the melting curve method. The JAK2 MutaQuant assay demonstrated analytic sensitivity of 0.01%. All 4 methods detected cases of BCR/ABL- MPNs and gave negative results with BCR/ABL+ chronic myelogenous leukemia, multiple myeloma, myelodysplastic syndrome, and normal cases.
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PMID:Clinical performance of JAK2 V617F mutation detection assays in a molecular diagnostics laboratory: evaluation of screening and quantitation methods. 1984 12

Myeloid leukemia in this series corresponds to the myeloid neoplasms of the 4th WHO classification of pathology and genetics of tumor of haematopoietic and lymphoid tissue. The myeloid neoplasms are composed of six categories, which are 1) myeloproliferative neoplasms (MPN), a new category of 2) myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1, 3) myelodysplastic syndrome (MDS)/MPN, 4) MDS, 5) acute myeloid leukemia (AML) and related precursor neoplasms, and 6) acute leukemias of ambiguous lineage. In MPNs without chronic myelogenous leukemia, the genetic marker of JAK2 V617F is added to the diagnostic criteria for polycythemia vera, essential thrombocythemia and primary myelofibrosis. MDS has the new subtype of refractory cytopenia with unilineage dysplasia composed of refractory anemia, refractory neutropenia and refractory thrombocytopenia. AML with t(9; 11) (p22;q23); MLLT3-MLL, AML with t(6;9) (p23; q34); DEK-NUP214, AML with inv(3) (q21q26.2) or t(3; 3) (q21 ; q26.2); RPN1-EVI1 and AML (megakaryoblastic) with t(1; 22) (p13; q13); RBM15-MKL1 are added to the subtype of AML with recurrent genetic abnormalities, and AML with gene mutations of NPM1 and CEBPA are also added as provisional entities of it. The myeloid neoplasms of the 4th WHO classification are comprehensive and seem to be dynamic by incorporating the results of leukemia researches.
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PMID:[Classification of myeloid leukemias]. 1986 Jan 79

Little was known about the mechanisms for myeloproliferative diseases (MPD) until 2005 when an activating mutation in the JAK2 tyrosine kinase (JAK2 V617F) was identified in >95% of patients with polycythemia vera (PV), and in a significant proportion of patients with essential thormbocythemia (ET) and primary myelofibrosis (PMF). Furthermore, activating abnormalities of some tyrosine kinases were identified in MPD and related diseases, suggesting that constitutive activation of the signaling pathway is a unifying feature of these diseases. On the other hand, the molecular mechanism of myelodysplastic syndromes (MDS) is still poorly understood. Recent study revealed that two types of AML1/RUNX1 mutants function via distinct molecular mechanisms to produce mutant-specific phenotypes of MDS. The mechanisms of MPD and MDS gradually become clear.
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PMID:[Molecular mechanisms in myeloproliferative diseases and myelodysplastic syndromes]. 1986 Jan 87

Copy number losses in chromosome arm 9p are well-known aberrations in malignancies, including leukemias. The CDKN2A gene is suggested to play a key role in these aberrations. In this study overviewing 9p losses in hematologic neoplasias, we introduce the term focal 9p instability to indicate multiple areas of copy number loss or homozygous loss within a larger heterozygous one in 9p. We have used microarray comparative genomic hybridization to study patients with acute lymphoblastic leukemia (ALL, n = 140), acute myeloid leukemia (n = 50), chronic lymphocytic leukemia (n = 20), and myelodysplastic syndromes (n = 37). Our results show that 9p instability is restricted to ALL. In total, 58/140 (41%) patients with ALL had a loss in 9p. The 9p instability was detected in 19% of the patients with ALL and always included homozygous loss of CDKN2A along with loss of CDKN2B. Other possibly important genes included MTAP, IFN, MLLT3, JAK2, PTPLAD2, and PAX5. 13/27 (48%) patients with the instability had the BCR/ABL1 fusion gene or other oncogene-activating translocation or structural aberrations. Two patients had homozygous loss of hsa-mir -31, a microRNA known to regulate IKZF1. IKZF1 deletion at 7p12.1 was seen in 10 (37%) patients with the 9p instability. These findings suggest that, in ALL leukemogenesis, loss of CDKN2A and other target genes in the instability region is frequently associated with BCR/ABL1 and IKZF1 dysfunction. The multiple mechanisms leading to 9p instability including physical or epigenetic loss of the target genes, loss of the microRNA cluster, and the role of FRA9G fragile site are discussed.
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PMID:Focal 9p instability in hematologic neoplasias revealed by comparative genomic hybridization and single-nucleotide polymorphism microarray analyses. 2001 97

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm that may display a variable degree of cytopenia and dysplasia sometimes difficult to distinguish from myelodysplastic syndrome with myelofibrosis (MDS-MF). We reviewed flow cytometric features of bone marrow from 70 cases of PMF and compared them with those from 17 cases of MDS-MF and 20 nonneoplastic control cases. The results were correlated with JAK2(V617F) and cytogenetic findings. Granulocytes and monocytes from PMF cases exhibited multiple dysplastic features overlapping with those of MDS-MF at a comparable or higher frequency: low side scattering, aberrant CD56 expression in granulocytes and monocytes, and an abnormal CD13/CD16 maturation pattern. Unique to PMF was the small granulocyte size compared with that of MDS-MF and control cases. Although the percentage of CD56+ granulocytes and monocytes did not correlate with JAK2(V617F) or cytogenetic abnormalities, a subset analysis of 36 cases revealed that median fluorescence intensity of CD56 expression correlated positively with the presence of cytogenetic abnormalities. Our findings indicate that although there is considerable overlap between PMF and MDS-MF, the smaller granulocytes observed in PMF are a useful distinguishing feature.
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PMID:Aberrant myeloid maturation identified by flow cytometry in primary myelofibrosis. 2009 42

Myelodysplastic syndromes and acute myeloid leukemia with an isodicentric X chromosome [idic(X)(q13)] occur in elderly women and frequently display ringed sideroblasts. Because of the rarity of idic(X)(q13), little is known about its formation, whether a fusion gene is generated, and patterns of additional aberrations. We here present an SNP array study of 14 idic(X)-positive myeloid malignancies, collected through an international collaborative effort. The breakpoints clustered in two regions of segmental duplications and were not in a gene, making dosage effects from the concurrent gain of Xpter-q13 and loss of Xq13-qter, rather than a fusion gene, the most likely pathogenetic outcome. Methylation analysis revealed involvement of the inactive X chromosomes in five cases and of the active in two. The ABCB7 gene, mutated in X-linked sideroblastic anemia and spinocerebellar ataxia, is in the deleted region, suggesting that loss of this gene underlies the frequent presence of ringed sideroblasts. Additional genetic abnormalities were present in 12/14 (86%), including partial uniparental disomies for 9p (one case) and 4q (two cases) associated with homozygous mutations of JAK2 and TET2, respectively. In total, TET2 mutations were seen in 4/11 (36%) analyzed cases, thus constituting a common secondary event in idic(X)-positive malignancies.
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PMID:The idic(X)(q13) in myeloid malignancies: breakpoint clustering in segmental duplications and association with TET2 mutations. 2009 95

The 3q21q26 syndrome is recognized as a distinct clinicopathologic entity. Patients have a myeloid neoplasm associated with 3q21q26 cytogenetic abnormalities and present with anemia, leukopenia, and either thrombocytosis or a normal platelet count associated with dysplasia. To determine if JAK2 V617F mutation is implicated in the abnormal thrombopoiesis of the 3q21q26 syndrome, we analyzed bone marrow samples of 12 patients, including 10 patients with acute myeloid leukemia and 2 patients with a myelodysplastic syndrome, associated with either inv(3)(q21;q26) or t(3;3)(q21;q26). The platelet count ranged from 142 to 597 x 10(3)/microL. Using polymerase chain reaction and pyrosequencing assays, no evidence of JAK2 V617F was identified in 11 of 12 cases. A JAK2 V617F mutation was identified in one patient who had acute myeloid leukemia with concurrent mast cell disease. Separate DNA analysis of myeloblasts and mast cells after laser capture microdissection confirmed that JAK2 V617F was present in both components. We conclude that JAK2 V617F mutation is uncommon in the 3q21q26 syndrome and that its presence may indicate an unusual coexistence of a myeloproliferative neoplasm.
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PMID:JAK2 V617F mutation is uncommon in patients with the 3q21q26 syndrome. 2015 5

The pathogenesis of myelodysplastic syndromes involves a pattern of genetic, epigenetic, and immune-mediated mechanisms but little is known about what causes the specific disease features and promotes disease progression in the individual patient. The identification of JAK2 and MPL mutations, and more recently TET2, CBL and ASXL-1 mutations in these disorders provide a basis for increased understanding of disease biology and mechanisms behind progression. Such mutations are more commonly found in patients with a significant amount of marrow ring sideroblasts, and in patients belonging to the category of mixed myelodysplastic/myeloproliferative neoplasms, entities which are in focus for this review.
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PMID:Significance of JAK2 and TET2 mutations in myelodysplastic syndromes. 2017 68

During the past few years our understanding of the genetic basis for the myelodysplastic syndromes (MDS) has improved significantly. A few subgroups have been studied in detail and the genetic alterations are now to a great extent revealed. In 5q- syndrome haploinsufficiency of the ribosomal gene RPS14 appears to cooperate with loss of two micro-RNAs miR-145 and miR-146 to induce key features of the disease. Some mutations are specific for certain categories of MDS while others, such as TET2 seem to occur across the various categories. JAK2 mutations are mainly found in patients with myeloproliferative characteristics. The prognostic implications of most of the novel mutations are not yet fully understood, moreover, functional studies are required in order to understand the interplay between the different lesions; how they give rise to the disease and how some may lead to disease evolution including leukemic transformation. An improved understanding of the pathophysiology of MDS may lead to the identification of suitable targets for future drug development.
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PMID:New clues to the molecular pathogenesis of myelodysplastic syndromes. 2021 Nov 65

While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of TET2/ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored ASXL1 and another 2 TET2 mutations. Phospho-STAT5 activation was present in one mutated TET2 and ASXL1 case. JAK2V617F/MPLW515L mutations were absent in TET2/ASXL1 mutants, indicating that similar clinical phenotype can be produced by various MPN-associated mutations and that additional unifying lesions may be present in RARS-T.
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PMID:Spectrum of mutations in RARS-T patients includes TET2 and ASXL1 mutations. 2033 14


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