1/93. Haemopoietic reconstitution by donor-derived myelodysplastic progenitor cells after haemopoietic stem cell transplantation.A 50-year-old woman who was retrospectively diagnosed with an early asymptomatic myelodysplastic syndrome (MDS) served as a haemopoietic stem cell donor for her HLA-identical sister who had chemotherapy-refractory non-Hodgkin's lymphoma. The MDS of the donor was classified as refractory anaemia (RA) and cytogenetically characterized by deletion of the long arm of chromosome 20 [del(20q)]. Donor cell engraftment in marrow and peripheral blood was analysed over a period of 5 months after transplant using conventional cytogenetics, fluorescence in situ hybridization, and variable number of tandem repeats. Neutrophil counts >0.5 x 109/l and platelet counts >20 x 109/l were reached promptly on days 12 and 24, respectively. Throughout the period of observation the percentage of cells with the del(20q) abnormality in the recipient's marrow and peripheral blood was comparable to the proportion of these cells in the donor. These data indicate that the abnormal clone was capable of homing to the marrow, proliferating, differentiating, and therefore contributing to haemopoiesis in a relatively efficient manner. This implies that MDS progenitor cells may not have homing and growth deficiencies, a finding that has particular relevance for autologous transplantation in MDS patients where tumour cells potentially contaminate the graft.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
2/93. Specific cutaneous lesions of the scalp in myelodysplastic syndrome with deletion of 20q.We reported a specific skin lesion on the scalp in a patient with myelodysplastic syndrome (MDS), treated as refractory anemia with excess of blasts (RAEB). Histologically, a specimen from a nodule of the scalp consisted of a diffuse infiltration of atypical cells in the dermis and subcutaneous tissue. The patient died of acute leukemia 3 months later. Chromosomal examination of bone marrow cells revealed deletion of 20q and 21 trisomy. The specific cutaneous lesions in this patient were associated with acute transformation. The deletion of 20q and specific cutaneous lesions are regarded as signs of poor prognosis.- - - - - - - - - - ranking = 2.293767501392keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
3/93. A new recurrent translocation, t(5;11)(q35;p15.5), associated with del(5q) in childhood acute myeloid leukemia. The UK Cancer cytogenetics Group (UKCCG)Partial deletion of the long arm of chromosome 5, del(5q), is the cytogenetic hallmark of the 5q-syndrome, a distinct subtype of myelodysplastic syndrome-refractory anemia (MDS-RA). Deletions of 5q also occur in the full spectrum of other de novo and therapy-related MDS and acute myeloid leukemia (AML) types, most often in association with other chromosome abnormalities. However, the loss of genetic material from 5q is believed to be of primary importance in the pathogenesis of all del(5q) disorders. In the present study, we performed fluorescence in situ hybridization (FISH) studies using a chromosome 5-specific whole chromosome painting probe and a 5q subtelomeric probe to determine the incidence of cryptic translocations. We studied archival fixed chromosome suspensions from 36 patients with myeloid disorders (predominantly MDS and AML) and del(5q) as the sole abnormality. In 3 AML patients studied, this identified a translocation of 5q subtelomeric sequences from the del(5q) to the short arm of an apparently normal chromosome 11. FISH with chromosome 11-specific subtelomeric probes confirmed the presence of 11p on the shortened 5q. Further FISH mapping confirmed that the 5q and 11p translocation breakpoints were the same in all 3 cases, between the nucleophosmin (NPM1) and fms-related tyrosine kinase 4 (FLT4) genes on 5q35 and the Harvey ras-1-related gene complex (HRC) and the radixin pseudogene (RDPX1) on 11p15.5. Importantly, all 3 patients with the cryptic t(5;11) were children: a total of 3 of 4 AML children studied. Two were classified as AML-M2 and the third was classified as M4. All 3 responded poorly to treatment and had short survival times, ranging from 10 to 18 months. Although del(5q) is rare in childhood AML, this study indicates that, within this subgroup, the incidence of cryptic t(5;11) may be high. It is significant that none of the 24 MDS patients studied, including 11 confirmed as having 5q-syndrome, had the translocation. Therefore, this appears to be a new nonrandom chromosomal translocation, specifically associated with childhood AML with a differentiated blast cell phenotype and the presence of a del(5q).- - - - - - - - - - ranking = 0.45875350027841keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
4/93. Extramedullary myeloid cell tumor of the urinary bladder in a patient with myelodysplastic syndrome.We report a case of extramedullary myeloid cell tumor of the urinary bladder in an elderly male with a three year history of myelodysplastic syndrome (refractory anemia with excess blasts), noninvasive papillary transitional cell carcinoma of the urinary bladder, and in situ transitional cell carcinoma of the left ureter. light microscopy demonstrated a poorly differentiated neoplasm composed of medium to large cells with eosinophilic cytoplasm. The tumor cells showed immunohistochemical expression of myeloperoxidase, lysozyme, CD15, CD68 and CD43. bone marrow examination following cystectomy demonstrated refractory anemia with excess blasts (6-10%) and a normal karyotype. cytogenetics, approximately 1 year after cystectomy, demonstrated a deletion of the short arm of chromosome number 12. Four years after presentation, the patient succumbed to pulmonary aspergillosis.- - - - - - - - - - ranking = 2.293767501392keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
5/93. monosomy 16 as the sole abnormality in myeloid malignancies.The majority of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients reported with chromosome 16 abnormalities had the inv(16)(p13q22) or t(16;16)(p13;q22) rearrangements, which were associated with a favorable prognosis. In contrast, del(16)(q22) was reported less commonly but was associated with a less favorable prognosis. We describe an 80-year-old woman who presented with MDS (refractory anemia). Chromosome analysis from bone marrow aspirate cultures showed monosomy 16 as the sole cytogenetic abnormality. Comparison of this patient with previously reported cases of monosomy 16 showed that this uncommon abnormality was associated with myeloid disorders. monosomy 16 patients, similar to del(16)(q22) patients, tended to be elderly, presented with MDS or AML, and had a poor prognosis. The similarity in clinical course for del(16)(q22) and monosomy 16 patients suggests that the phenotype in both groups resulted from loss of important gene(s) on 16q, as distinct from the fusion gene product identified in the inv(16) and t(16;16) rearrangements.- - - - - - - - - - ranking = 0.45875350027841keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
6/93. Interstitial deletion of the short arm of chromosome 12 during clonal evolution in myelodysplastic syndrome with t(5;12)(q13;p13) involving the ETV6 gene.We report here a 65-year-old man with a myelodysplastic syndrome (MDS), refractory anemia with excess of blasts. He had received chemotherapy with tegafur for renal carcinoma. Chromosome analysis of bone marrow cells revealed complex karyotypes; del(5)(q13) was observed in all 20 metaphase spreads, and two related aberrations, add(12)(p11) and add(12)(p13), were detected in 13 and 7 cells, respectively. fluorescence in situ hybridization (FISH) analysis with chromosome-specific DNAs revealed that these alterations originated from a reciprocal translocation (5;12)(q13;p13). Therefore, del(5)(q13), add(12)(p11), and add(12)(p13) were revised as der(5)t(5;12)(q13;p13), der(12)del(12)(p11p13)t(5;12)(q13;p13), and der(12)t(5;12)(q13;p13), respectively. fluorescence in situ hybridization with a series of cosmid probes spanning the ETV6 gene showed that the 12p13 breakpoint on the der(12)t(5;12)(q13;p13) was located in intron 1, but the exon 1 signal was deleted. Our results suggest that a fusion gene was generated between the 5'-end of an unidentified partner at 5q13 and the 3'-end of ETV6 by t(5;12)(q13;p13), and that the interstitial deletion (12)(p11p13) occurred following t(5;12) during clonal evolution. del(12)(p11p13), including the rearranged ETV6 gene, may be implicated in the progression of MDS.- - - - - - - - - - ranking = 2.293767501392keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
7/93. The human GRAF gene is fused to MLL in a unique t(5;11)(q31;q23) and both alleles are disrupted in three cases of myelodysplastic syndrome/acute myeloid leukemia with a deletion 5q.We have isolated the human GRAF gene (for GTPase regulator associated with the focal adhesion kinase pp125(FAK)). This gene was fused with MLL in a unique t(5;11)(q31;q23) that occurred in an infant with juvenile myelomonocytic leukemia. GRAF encodes a member of the Rho family of the GTPase-activating protein (GAP) family. On the protein level, it is 90% homologous to the recently described chicken GRAF gene that functions as a GAP of RhoA in vivo and is thus a critical component of the integrin signaling transduction pathway. The particular position of the human GRAF gene at 5q31 and the proposed antiproliferative and tumor suppressor properties of its avian homologue suggest that it also might be pathogenetically relevant for hematologic malignancies with deletions of 5q. To investigate this possibility, we sequenced 4-5 individual cDNA clones from 13 cases in which one allele of GRAF was deleted. We found point mutations within the GAP domain of the second GRAF allele in one patient. In two additional patients we found an insertion of 52 or 74 bp within the GRAF cDNA that generates a reading frame shift followed by a premature stop codon. GRAF maps outside the previously defined commonly deleted 5q31 region. Nevertheless, inactivation of both alleles in at least some cases suggests that deletions and mutations of the GRAF gene may be instrumental in the development and progression of hematopoeitic disorders with a del(5q).- - - - - - - - - - ranking = 1.8350140011136keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
8/93. Clonal monosomy 7 and 5q--in a child with myelodysplastic syndrome.The authors report the case of a 5-year-old boy referred for thrombocytopenia and neutropenia. bone marrow examination showed a myelodysplasia with clonal monosomy 7. The acceleration of the disease was marked by the appearance of an additional cytogenetic abnormality, i.e., the deletion of the long arm of chromosome 5 in the clonal cells. RAS gene mutation was not detected. Chemotherapy was started to achieve complete remission before a bone marrow transplantation. This treatment was complicated by a prolonged aplasia and the patient died of systemic mycotic infection.- - - - - - - - - - ranking = 1.8350140011136keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
9/93. A novel dicentric deleted chromosome 21 arising from tandem translocation.We present a 26-year-old patient with myelodysplastic syndrome (MDS). Initial bone marrow cytogenetics with G-banding showed a rearranged chromosome 21, which was dicentric and bisatellited on CBG- and NOR-banding. fluorescence in situ hybridization helped to characterize the structure, using a whole chromosome 21 paint and the locus specific AML1 gene probe. The rearranged 21 consisted solely of chromosome 21 material, contained only one copy of AML1, and was not a trisomy, but a deleted tandem translocation. The MDS transformed to acute myeloid leukemia (AML), and the patient died almost 12 months post-diagnosis. cytogenetics was performed three times during the course of the disease, and the dicentric chromosome 21 was present throughout. Although there are a number of published rearrangements of chromosome 21 in MDS and AML, most are isodicentrics. We could not find another case of an abnormal chromosome 21 with the same structure as reported here.- - - - - - - - - - ranking = 0.45875350027841keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
10/93. Therapy-related myelodysplastic syndrome after eradication of acute promyelocytic leukemia: cytogenetic and molecular features.The use of all trans-retinoic acid and combination chemotherapy has made acute promyelocytic leukemia (APL) a potentially curable leukemia. Late sequelae of the treatment of APL have therefore become an important consideration in the overall treatment strategy. We report a patient with APL who achieved complete clinical and molecular remission after treatment with the topoisomerase ii inhibitors daunorubicin, mitoxantrone, etoposide, and the anti-metabolite cytosine arabinoside. Seven years later, she developed therapy-related myelodysplastic syndrome (t-MDS) without any evidence of relapse of the APL clone. Karyotypic and molecular cytogenetic analysis showed complex cytogenetic aberrations, including deletion of the long arm of chromosome 5, monosomy 7, but without rearrangement of the MLL gene/11q23. Interestingly, this case would be classified clinically as "epipodophyllotoxin related MDS," but pathologically as "alkylating-agent related MDS" according to the recently proposed world health organization (WHO) classification system for MDS. This case of t-MDS in an APL patient in durable remission highlights the importance of avoiding long-term treatment related toxicities, as APL is a potentially curable leukemia.- - - - - - - - - - ranking = 2.293767501392keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
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