1/94. monosomy X as the sole cytogenetic abnormality in acute lymphoblastic leukemia: a report of two new patients.monosomy X as the sole acquired cytogenetic abnormality is usually found in myeloid hematological malignancies, especially those with myelodysplastic features. Only three cases of acute lymphoblastic leukemia (ALL) with this abnormality have been previously reported. We add two cases to this series and comment on the likelihood of a tumor suppressor gene being located on the x chromosome.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
2/94. Detection of monosomy 7 in bone marrow by fluorescence in situ hybridization. A study of fanconi anemia patients and review of the literature.monosomy 7 is frequently found in the bone marrow of patients with fanconi anemia (FA), marrow myelodysplasia, or acute myelogenous leukemia and is associated with poor prognosis. In our laboratory, cytogenetic analysis of bone marrow from an FA patient found 2 of 30 cells with monosomy 7, but the results of fluorescence in situ hybridization (FISH) indicated that 83 of 207 cells (40%) had monosomy 7. FISH was then used to analyze two earlier samples from the index case, neither of which had monosomy 7 as determined by standard cytogenetics. The FISH analysis determined that the first sample, taken 19 months earlier, had 8 of 200 cells (4%) with monosomy 7 and the second sample. taken 7 months later, contained 43 of 200 cells (21.5%) with monosomy 7. These results indicate a slow evolution toward monosomy 7 in the patient's bone marrow. Standard metaphase chromosome analysis represents only spontaneously dividing cells, leading us to hypothesize that FISH was detecting monosomy 7 in nondividing cells and that it might be useful in the early detection of abnormal clones. To test this hypothesis, FISH was performed on 13 bone marrow samples from nine patients with FA who did not exhibit monosomy 7 by cytogenetic analysis. monosomy 7 was detected in 3.44% of nuclei in FA patients and in 3% of nuclei in normal controls. To date, none of these nine FA patients have developed monosomy 7 or leukemia. They are being monitored by standard cytogenetics and by FISH to determine whether monosomy 7 develops and whether it can be detected by FISH prior to its detection by standard cytogenetics. As standard practice, we have adopted FISH analysis for monosomy 7 in all patients with FA.- - - - - - - - - - ranking = 0.45473934692783keywords = leukemia, myelogenous, myelogenous leukemia (Clic here for more details about this article) |
3/94. Lineage switch in childhood leukemia with monosomy 7 and reverse of lineage switch in severe combined immunodeficient mice.Morphophenotypic lineage switches occur in a small percentage of those with acute leukemia, and the underlying mechanisms are not clear. In this study, we attempted to induce a lineage switch in acute myelocytic leukemia (AML) with monosomy 7, whose lineage had switched from acute T-lymphocytic leukemia (T-ALL) during chemotherapy, in severe combined immunodeficient (SCID) mice. Although the transplanted myeloid cells were engrafted in SCID mice without cytokine administration, T-ALL developed in SCID mice treated with recombinant human granulocyte-macrophage colony-stimulating factor or recombinant human interleukin 3. Analysis of the nucleotide sequences of the rearranged T-cell receptor gamma-chain (TCR-gamma) gene revealed that this lineage switch resulted from the selection of the T-lineage subclone in SCID mice, which had expanded at onset. In addition, we found that the T-lineage and myeloid cells belonged to the distinct subclones, which were different in TCR-gamma gene rearrangements, but were derived from a common clone with an identical N-ras gene mutation for both subclones. In in vitro cultures, only the myeloid subclone grew; the T-lineage subclone failed to grow even in the presence of recombinant human granulocyte-macrophage colony-stimulating factor or recombinant human interleukin 3. These results suggested that the initial diagnostic T-lymphoid subclone, whose growth was dependent on these cytokines and the hematopoietic microenvironment, emerged from a bipotential T-lymphoid/myeloid leukemic stem cell, and further genetic event(s) induced the myeloid subclone, which grew independently of these cytokines and the microenvironment.- - - - - - - - - - ranking = 1.4837776357848keywords = leukemia, myelocytic leukemia, myelocytic (Clic here for more details about this article) |
4/94. Extramedullary relapse despite graft-versus-leukemia effect after bone marrow transplantation in a girl with juvenile myelomonocytic leukemia.A 12 year-old girl with juvenile myelomonocytic leukemia (JMML) and monosomy 7 underwent allogeneic bone marrow transplantation (BMT) from her HLA-matched brother. To monitor the engraftment and the course of the disease we used fluorescence in situ hybridization (FISH) with probes specific for the centromeres of chromosomes X, Y and 7. Complete hematological remission was achieved and confirmed by the virtually exclusive presence of normal male cells in the bone marrow (BM). Acute graft-versus host disease (GvHD) was treated with prednisone and cyclosporine A (CSA) and female cells with monosomy 7 reoccurred in the peripheral blood (PB) and BM. After discontinuation of the immunosuppressive therapy, the leukemic cells with monosomy 7 disappeared again from these compartments. One year after transplantation, isolated extramedullary relapses occurred in lymph nodes and skin, followed by dissemination of blast cells into the BM, whereas the PB cells remained of donor origin. The fact that the leukemic cells fluctuated with the intensity of the immunosuppressive treatment provides evidence of a graft versus leukemia (GvL) effect in this unusually old girl with JMML with a unique extramedullary disease progression.- - - - - - - - - - ranking = 2keywords = leukemia (Clic here for more details about this article) |
5/94. Acute trilineage leukemia with monosomy of chromosome 7 following an acute promyelocytic leukemia.We describe an 8 year old boy who had received chemotherapy for an acute promyelocytic leukemia and developed a secondary leukemia 27 months after the diagnosis of this first malignancy. Blasts cells were positive for cytoplasmic markers CD22, CD3 and myeloperoxidase. Cell surface T and myeloid-associated markers were also detected. Cytogenetic study disclosed monosomy 7. The patient achieved complete remission, but relapsed 15 months later with identical immunophenotypic and cytogenetic findings. Three-lineage commitment is proved by the expression of specific criteria for myeloid, and lymphoid T and B typing. A multipotent immature progenitor must be the target of leukemogenic agents. The prognosis is obviously ominous.- - - - - - - - - - ranking = 2.4188881789239keywords = leukemia, myelocytic leukemia, myelocytic (Clic here for more details about this article) |
6/94. Loss of maternal allele in a child with myelodysplastic syndrome and monosomy 7.monosomy 7 or partial deletion of the long arm of chromosome 7 is frequently described in children with myelodysplastic syndrome and acute myeloblastic leukemia. Parental origin of chromosome 7 in children with sporadic monosomy 7 has been examined very rarely. To investigate if monosomy 7 shows parent-of-origin, we have studied a female child with monosomy 7 and de novo myelodysplastic syndrome by a series of polymorphic polymerase chain reaction markers. We found loss of maternal allele and discussed the results with the previous reports.- - - - - - - - - - ranking = 0.2keywords = leukemia (Clic here for more details about this article) |
7/94. A novel BCR-ABL transcript e2a2 in a chronic myelogenous leukaemia patient with a duplicated Ph-chromosome and monosomy 7.A novel BCR-ABL transcript was detected by multiplex RT-PCR in a patient with philadelphia chromosome (Ph) positive chronic myelogenous leukaemia (CML) in accelerated phase. Sequencing of the aberrant transcript revealed an in-frame e2a2 fusion that included a 9 basepairs insertion. cytogenetic analysis showed t(9;22), an additional Ph chromosome and monosomy 7. The clinical course was dismal: therapy was poorly tolerated, and the patient died in blast crisis 10 months after diagnosis. These data support the association of additional Ph and monosomy 7 with poor prognosis and suggest that the novel e2a2 BCR-ABL transcript may be related to an aggressive clinical course.- - - - - - - - - - ranking = 0.19811417414825keywords = myelogenous (Clic here for more details about this article) |
8/94. Extensive cytogenetic studies of clonality following interferon-alpha therapy in chronic myeloid leukemia occurring in monosomic cells in a patient with turner syndrome mosaic.In a 27-year-old female with turner syndrome mosaic, Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) occurred only in the monosomic cells (45, Xc). Extensive cytogenetic studies, including triple-color fluorescence in situ hybridization (FISH), revealed that Ph-positive monosomic cells (45, Xc), Ph-negative monosomic cells and normal diploid cells (46, XX) were present in her bone marrow at diagnosis. After successful interferon therapy, the non-leukemia cells expanded and reconstituted normal hematopoiesis resulting in complete cytogenetic response, following the selective suppression of the monosomic Ph-positive leukemia clone. The ratio of Xc to XX cells in bone marrow cells was significantly increased to that in skin fibroblasts. Moreover, the ratio of Ph-positive cells to Ph-negative cells was found to be significantly different between karyotyping and FISH. Studies of this quite unique case not only confirmed the clonality of CML, effectiveness of interferon-alpha and x chromosome imbalance among different tissues, but also demonstrated a discrepant increase of the BCR/ABL-positive clone in CML. The latter supports the hypothesis that reduced programmed cell death may be the primary mechanism responsible for the expansion of the leukemia clone in CML. Our study verifies the importance of extensive analysis of a neoplastic disease in patients with a constitutional chromosomal abnormality.- - - - - - - - - - ranking = 1.6641576887107keywords = leukemia, myeloid leukemia (Clic here for more details about this article) |
9/94. Discordant detection of monosomy 7 by GTG-banding and FISH in a patient with Shwachman-diamond syndrome without evidence of myelodysplastic syndrome or acute myelogenous leukemia.The myelodysplastic syndromes (MDS) are a group of hematologic disorders commonly affecting elderly persons and often leading to acute myelogenous leukemia (AML). Although rare in children, when MDS does occur, it is frequently part of a congenital disorder such as Shwachman-diamond syndrome (SDS). monosomy 7 and/or deletion of part or all of 7q are poor prognostic signs in MDS and AML, although the pathophysiologic relationship between this finding and MDS or AML is unclear. Shwachman-diamond syndrome is an inherited illness characterized by exocrine pancreatic insufficiency and by congenital neutropenia. patients with SDS are at increased risk of developing myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML). Because monosomy 7 is a poor prognostic sign in MDS and AML, establishing its presence is important. However, different methods of detection of monosomy 7 may lead to different results in some patients. We present the case of a 10-year-old girl known to have SDS, who had a bone marrow aspiration and biopsy done to rule out MDS and AML. By light microscopy, the patient's bone marrow was unremarkable. GTG-banding showed the following karyotype: 45,XX,-C[3]/47,XX, C[1]/46,XX[45]. fluorescence in situ hybridization (FISH) was performed with a chromosome 7-specific alpha-satellite probe (D7Z1). Almost all (373 of 376) cells exhibited only one chromosome 7 signal. A second marrow aspiration done 6 months later showed an essentially normal karyotype by GTG-banding. fluorescence in situ hybridization with the same chromosome 7 probe showed 230 of 250 cells to be monosomic for chromosome 7. A whole chromosome 7 painting probe demonstrated disomy for chromosome 7 in 90 of 90 cells; however, subtle heteromorphism in the centromeric regions of the 2 copies of chromosome 7 was noted in some cells. This case demonstrates that FISH and GTG-banding can give discordant results, that the two should be viewed as complementary technologies, and that both have a place in a full karyotypic analysis. Furthermore, this case demonstrates for the first time that heteromorphism and/or subtle structural abnormalities of chromosome 7, previously associated with MDS and AML, can exist without clinical or morphologic signs of these illnesses. It will be of interest to further study the relationship, if any, between SDS and various structural abnormalities of chromosome 7 in MDS and AML, and to elucidate the molecular mechanisms of pathogenesis, physiology, and treatment of these disorders.- - - - - - - - - - ranking = 1.528436081567keywords = leukemia, myelogenous, myelogenous leukemia (Clic here for more details about this article) |
10/94. trisomy 11 and a complex t(11;11;22) in a patient with acute myelomonocytic leukemia (AML-M4) following myelodysplasia (MDS): a cytogenetic study of a mechanism of leukemogenesis.We describe a 73-year-old man diagnosed with acute myelomonocytic leukemia (AML-M4) following myelodysplasia with trisomy 11 and with a t(11;11;22). This is the first case with both abnormalities present in the same cells and with the t(11;11;22) involving a chromosome 11 already duplicated at 11q23. This band contains the MLL gene that undergoes partial tandem duplication in patients with 11, which is "promiscuous," being translocated with a large number of genetic partners. Our patient had a complex karyotype that was completely defined by in situ hybridization. This technique demonstrated that the t(11;11;22) derivative with a duplication of band 11q23 carried from three to four copies of MLL. Two copies of the gene were close to each other and centromeric to the break-point region. Therefore, a partial tandem duplication of the MLL gene might have happened before the occurrence of t(11;11;22). Considering the associated chromosome defects, the monosomy for the long arm of chromosome 7, due to an unbalanced translocation t(7;17), further underlines the possibility that a partial tandem duplication of the MLL gene might have taken place.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
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