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

In a patient with recently diagnosed chronic myelomonocytic leukemia features, the biopsy of a peripheral lymphadenopathy seven months later revealed disorganised lymphoid tissue with a few large EBER (+) LMP1 (+) B-lymphocytes before any treatment was given. At this time, a clonal TCR gamma rearrangement and very faint clonal IgH rearrangement were demonstrated, and the diagnosis of angioimmunoblastic T-cell lymphoma was made. Treatment with MOPP was started, followed by Hydroxycarbamide and CHOP but the outcome was fatal. During the evolution, there was no blastic transformation of the chronic myelomonocytic leukemia. The T-cell lymphoma extended to abdominal lymph nodes, Waldeyer ring and bone marrow and the percentage of large LMPI EBER (+) B-cells increased in the lymph nodes. These findings do not support a common stem cell abnormality leading to myelodysplasia in the bone marrow and lymphoma in peripheral lymph nodes. The lack of a clearcut light chain restriction in the EBV infected B-cell is suggestive of a persistant EBV infection in polyclonal or oligoclonal activated B-cells as described in immunodepressed patients. The association of CMML features and an angioimmunoblastic T-cell lymphoma is discussed.
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PMID:Occurrence of angioimmunoblastic T cell lymphoma in a patient with chronic myelomonocytic leukemia features. 1142 21

TET (Ten Eleven Translocation) family proteins are dioxygenases that convert methylcytosine to hydroxymethylcytosine, and play an important role in the DNA demethylation process. Most notably, TET2 mutations have frequently been identified in myeloid malignancies, such as myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), chronic myelomonocytic leukemia, and acute myeloid leukemias, as well as angioimmunoblastic T-cell lymphoma and a proportion of peripheral T-cell lymphomas. To date, various types of Tet2 knockout/knockdown mice have been generated. Tet2 mutations induce enhanced self-renewal ability and competitive repopulation capacity in hematopoietic stem cells, and various MPN/MDS-like diseases and T-cell lymphoma consequently develop in model mice. These findings appear to have a strong correlation with the recently identified TET2 mutations in a significant proportion of healthy elderly people, and suggest that TET2 mutations lead to a pre-cancer state in hematopoietic stem/progenitor cells. In conclusion, TET2 might play a major role as a gate keeper for hematopoietic stem/progenitor cells preventing them from developing into various hematologic malignancies by acquiring additional disease-specific gene mutations.
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PMID:[TET2 as a gatekeeper for hematologic malignancies]. 2625 75

A 75-year-old man with no prior history of cytotoxic therapy presented with increasing fatigue and shortness of breath. He was found to have a new onset of pancytopenia, and chest X-ray showed severe pneumonia. Additional radiology exam revealed pan-lobar pneumonia, pleural effusion, generalized lymphadenopathy and mild splenomegaly. Bone marrow and mediastinal lymph node biopsy from the bilateral level 4 lymph nodes were performed to evaluate the cause of pancytopenia and generalized lymphadenopathy, respectively. Histologic sections of lymph nodes were consistent with angioimmunoblastic T-cell lymphoma (AITL), and bone marrow biopsy showed low level involvement by AITL. Background trilineage hematopoiesis showed features suggestive of myelodysplastic syndrome (MDS) with karyotyping showing deletion 20q; however, interpretation of dysplasia and exclusion of reactive process was difficult due to the presence of severe infection, administration of multiple medications and multiorgan failure. Therefore, to further evaluate the possibility of concomitant myeloid neoplasm, we performed flow cytometry sorting of bone marrow aspirate to isolate the myeloid cell population from the abnormal T-cell population, and comprehensive genomic profiling was performed in each population separately. Flow-sorted myeloid population showed three somatic mutations involving DNMT3A and BCORL1, supporting the diagnosis of MDS in conjunction with the presence of deletion 20q. Flow sorted abnormal T-cell population showed six somatic mutations consistent with AITL, involving Ras homolog gene family member A (RHOA), TET2, DNMT3A, NOTCH2 and XPO1. These two sorted populations shared the DNMT3A p.N612Rfs*26 mutation, and the variants unique to one sorted population were confirmed to be completely absent in another sorted population by manual review of the sample. These findings suggested that the two neoplasms were clonally related and were sharing a common hematopoietic progenitor precursor, but underwent clonal divergence over time, leading to the development of two distinct neoplastic processes of T and myeloid lineages. This illustrates a rare case of concurrent diagnosis of AITL and de novo MDS and reliable genomic assessment was performed at the time of diagnosis to detect mutations in each neoplastic process without contamination. Further studies are needed to assess hypomethylating agents as potential therapy options for these patients.
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PMID:Molecular Genetic Analysis With Flow Cytometry Sorting Identifies Angioimmunoblastic T-Cell Lymphoma and Concomitant De Novo Myelodysplastic Syndrome Arising From the Same Hematopoietic Progenitor. 3322 95