1/15. 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 = 1keywords = hybridization (Clic here for more details about this article) |
2/15. A group of previously not recognized cytogenetic abnormalities in myeloid hematological malignancies.We have identified a group of previously not reported chromosome abnormalities related to myeloid hematological malignancies. Cases 1 and 2 were observed to have an additional i(4)(p10) as the sole anomaly with similar clinical features of myeloid disorders; that is, acute nonlymphocytic leukemia (ANLL-M2) and myelodysplastic syndrome (MDS)-refractory anemia with an excess of blasts in transformation, respectively. fluorescence in situ hybridization studies with the use of a 4p-specific microdissection probe further confirmed the presence of an i(4)(p10) in these patients. Case 3 was diagnosed with ANLL-M1 and had an additional i(8)(p10) as the only change, also confirmed by a whole-chromosome painting procedure. In cases 4-6, deletions of 18q at breakpoints q12, q23, and q21 were identified as the sole anomaly in a myeloproliferative disorder (MPD), MPD, and MDS, respectively. X-autosome translocations other than t(X;10)(p11;p11) and t(X;11)(q13;q23) have not been reported as recurrent or primary changes in hematological disorders. In the present study, a t(X;9)(q26;q22) and t(X;5)(q13;q33) as the sole anomaly were found in cases 7 and 8, respectively. Both cases had the same diagnosis of MDS. Considering that trisomies 4 ( 4) and 8 ( 8) are common anomalies in MDS and ANLL, our findings strongly indicate that amplification of genes on 4p and 8p, but not on 4q and 8q, may play a crucial role in the pathogenesis of MDS and ANLL. In addition, genes on 18q12-23 and on Xq13-26 may be involved in the pathogenesis of myeloid disorders.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/15. Pentasomy 8q resulting from duplication of isochromosome 8q in chronic myelomonocytic leukemia.We report an interesting case of chronic myelomonocytic leukemia (CMML) with pentasomy 8q resulting from the duplication of isochromosome 8q in a 47-year-old male. His blood picture and myelogram showed CMML and the chromosome study, using R-banding and G-banding techniques, revealed a karyotype of 47,XY,-8, i(8)(q10)x2. Dual-color fluorescence in situ hybridization (FISH) studies with a #8 centromeric probe and a locus-specific probe for C-myc gene completely confirmed the result of the conventional cytogenetic method. reverse transcription polymerase reaction (RT-PCR) revealed no BCR/ABL fusion transcript. hydroxyurea and 6-mercaptopurine therapy did not induce a complete remission and five months later he died of exacerbation of his disease. On reviewing another two cases with pentasomy 8q in the literature, we feel that pentasomy 8q, when present as a sole anomaly, may play a specific role in leukemogenesis and in determining the clinical characteristics such as monocytic involvement and poor prognosis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/15. A novel cryptic translocation t(12;17)(p13;p12-p13) in a secondary acute myeloid leukemia results in a fusion of the ETV6 gene and the antisense strand of the PER1 gene.The ETV6 gene is a member of the ETS family of transcription factors and the main target of chromosomal rearrangements affecting chromosome band 12p13. To date, more than 15 fusion partners of ETV6 have been characterized at the molecular level. Most of these fusions encode chimeric proteins with oncogenic properties. However, some of the translocations do not produce a functional fusion protein, but may induce ectopic expression of oncogenes located close to the breakpoint. We herein report the characterization and cloning of a novel cryptic translocation, t(12;17)(p13;p12-p13), occurring in a patient with an acute myeloid leukemia evolving from a chronic myelomonocytic leukemia. cytogenetic analysis suggested the presence of a deletion of the short arm of chromosome 12, del(12)(p13), in three of the five metaphase cells analyzed. However, fluorescence in situ hybridization (FISH) with the ETV6-specific cosmid clones 179A6, 50F4, 163E7, and 148B6 as well as probes hybridizing to the TP53 gene on 17p13 and the subtelomeric region of 17p revealed the presence of a translocation between 12p and 17p. By FISH, the breakpoints could be localized in intron 1 of ETV6 and centromeric to TP53. By 3' rapid amplification of cDNA ends-polymerase chain reaction (3' RACE-PCR), a fusion transcript between exon 1 of ETV6 and the antisense strand of PER1 (period homolog 1, drosophila), a circadian clock gene, could be identified. This ETV6-PER1 (antisense PER1 strand) fusion transcript does not produce a fusion protein, and no other fusion transcripts could be detected. We hypothesize that in the absence of a fusion protein, the inactivation of PER1 or deregulation of a gene in the neighborhood of PER1 may contribute to the pathogenesis of leukemias with a t(12;17)(p13;p12-p13).- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/15. HCMOGT-1 is a novel fusion partner to PDGFRB in juvenile myelomonocytic leukemia with t(5;17)(q33;p11.2).PDGFRB, a transmembrane tyrosine kinase receptor for platelet-derived growth factor, is constitutively activated by gene fusion with different partners in myeloproliferative/myelodysplastic disorders with peculiar clinical characteristics. Six alternative partner genes have been described thus far. In this study, we report the molecular cloning of a novel translocation t(5;17)(q33;p11.2) in a case of juvenile myelomonocytic leukemia. The novel partner gene was identified as HCMOGT-1 using 5'-rapid amplification of cDNA ends; fluorescence in situ hybridization and reverse transcriptase-PCR analyses confirmed that the translocation resulted in PDGFRB/HCMOGT-1 fusion. We show that the breakpoint of PDGFRB occurred at the same site of all previously reported PDGFRB translocations.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/15. A der(14)t(1;14)(q12;p11) in chronic myelomonocytic leukemia.Duplication of the long arm of chromosome 1 (1q) is widely reported in human neoplasia, including the myelodysplastic syndromes (MDS). So far, it has not been described as a single aberration in the chronic myelomonocytic leukemia (CMML), a subtype of MDS. Rather, trisomy 1q was always a part of complex chromosome changes affecting the subtypes of MDS other than CMML. We report on a patient with CMML with an unbalanced translocation of the entire 1q onto the short arm of chromosome 14 as a sole cytogenetic abnormality. fluorescence in situ hybridization (FISH) analysis with an alpha-satellite probe for the paracentric region of the long arm of chromosome 1 confirmed the presence of trisomy 1q in a derivative chromosome, der(14)t(1;14)(q12;p11). The discrepant results between the metaphase cytogenetics (100% abnormal) and interphase cytogenetic (71% nuclei with 3 signals) suggest that trisomy 1q, even in the absence of additional cytogenetic changes, has a sufficient leukemogenic potential to confer a proliferative advantage on hematopoietic cells committed to monocyte stemline both in vitro and in vivo. The literature data on partial and complete trisomy 1q in CMML is reviewed.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/15. A case of chronic myelomonocytic leukemia with severe eosinophilia having t(5;12)(q31;p13) with t(1;7)(q10;p10).We describe an unusual case of chronic myelomonocytic leukemia with severe eosinophilia having t(5;12)(q31;p13) with t(1;7)(q10;p10). The eosinophilic proliferation was severe in peripheral blood and bone marrow, and they revealed marked dysplastic features. We performed fluorescence in situ hybridization (FISH) and immunohistochemistry to evaluate the clonality of eosinophils. The eosinophils were stained positively to platelet-derived growth factor receptor-beta. By FISH using chromosome 1 satellite probe and chromosome 1q telomere probe, the eosinophils were proved to belong to the malignant clone.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/15. Rearrangement of proximal 11q13 band in a CMML in acute transformation.fluorescence in situ hybridization (FISH) was performed on bone marrow cells thought to contain a t(7;11)(p22;q13) from a patient with chronic myelomonocytic leukemia in transformation. FISH analysis using a panel of 10 probes previously mapped to 11q13 revealed a cytogenetically undetected complex rearrangement that involved chromosomes 7 and 11 as well as a chromosome 3 at band p24. Two distinct translocation breakpoints, both proximal to the BCL1 locus, were found in chromosome 11 that perforce separate it into three subregions. The two breakpoints appear distinct from the two previously described ones which involved the FAU and GSTP1 genes. Our observations add to the involvement of proximal 11q13 in myeloid malignancies.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/15. Cytogenetic clonality in chronic myelomonocytic leukemia studied with fluorescence in situ hybridization.Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome (MDS) subtype, characterized by monocytosis, dysgranulocytosis and a low number of blast cells in the peripheral blood (PB). The clonal nature of MDS has been demonstrated by various techniques: the stem cell involved initially is capable of myeloid and lymphoid differentiation. Fluorescent in situ hybridization (FISH) is a technique which can be utilized without any pretreatment on whole interphase cells. In this study leukocytes of PB Wright-stained smears from four CMML patients with trisomy 8 (three cases) and 9 (one case) have been analyzed by FISH. Utilizing a probe for the centromere of chromosome 8 and for the heterochromatic region of chromosome 9, we observed the cells involved by trisomy. In each of the four cases neutrophils, eosinophils, basophils and monocytes may show trisomy 8 or 9, whereas lymphocytes resulted disomic. The comparison between leukocytes morphology and genotype suggests that the supernumerary chromosome does not influence cellular differentiation and maturation. We conclude that FISH analysis of PB leukocytes of patients with CMML is informative when studying the clonality of the disease. Chromosomal abnormalities seem to involve a hematopoietic cell committed to myeloid but not lymphoid differentiation. Trisomies 8 and 9 seem to confer some proliferative advantage without influencing the morphologic characteristics of leukocytes. Other causes will be investigated to explain dysmorphisms of neutrophils and monocytes typical of this disease.- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |
10/15. Myelomonocytic crisis with t(5;17) and a p53 mutation in a patient with chronic myelogenous leukemia.We report a 64-year-old Japanese man with chronic myelogenous leukemia (CML) who expired with myelomonocytic crisis. Cytogenetic analyses of chronic phase (CP) and accelerated phase (AP) cells revealed a philadelphia chromosome and an isochromosome for the long arm of chromosome 17, i(17q). This karyotype was replaced by another karyotype in blast crisis (BC), resulting in near triploidy with t(5;17) (p15;p11) and loss of chromosome 17 pter-->p11. interphase fluorescent in situ hybridization studies with a chromosome 17 specific alpha satellite dna probe confirmed the presence of a clonal change in BC. In addition, single-strand conformation polymorphism analysis and PCR-direct sequencing of BC cells revealed a point mutation at codon 203 of the p53 gene, GTG to GAG (Val to Glu), and loss of the normal allele. In contrast, no alterations of the p53 gene were found in CP and AP cells. Therefore, progression of CML in this patient appeared to be related to loss of 17p, as well as a mutation in the p53 gene.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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