1/6. A novel t(16;20)(q22;p13) in polycythemia vera.We report a patient with polycythemia vera whose bone marrow cells carried a novel t(16;20)(q22;p13) as detected by karyotype analysis using G- and Q-banding techniques. The reciprocal translocation was confirmed by fluorescence in situ hybridization (FISH) using dna libraries of chromosomes 16 and 20. To our knowledge, t(16;20)(q22;p13) has not been reported previously. The core binding factor beta (CBFbeta) gene located on 16q22 is known to be frequently involved in acute myelocytic leukemia. On the other hand, the 20p13 locus contains a gene encoding protein kinase CK2alpha, which is closely related to cell proliferation and cell cycle regulation. The t(16;20)(q22;p13) may be one of the cytogenetic aberrations in myeloproliferative disorders, and therefore, our observation warrants further studies on a possible involvement of the genes resulting from this translocation.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/6. Translocation (X;20)(q13.1;q13.3) as a primary chromosomal finding in two patients with myelocytic disorders.Reports of x chromosome translocations, as primary chromosomal changes associated with hematologic disorders, remain relatively uncommon. Herein, we report the detection, by conventional cytogenetic methods, of a cytogenetically identical t(X;20) in two different patients with hematologic disorders (probable myelodysplasia and polycythemia vera/acute myelocytic leukemia). In both cases, this translocation appeared as the primary clonal chromosome abnormality, with breakpoints occurring in the long arms of both the x chromosome and chromosome 20 (Xq13.1 and 20q13.3, respectively). Further characterization and comparison of the translocation chromosome products of these two cases by use of fluorescence in situ hybridization techniques is also described. Similar previously reported cytogenetically cases and the potential that this specific rearrangement may represent a nonrandom chromosomal finding are discussed.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/6. Simultaneous genotypic and immunophenotypic analysis of interphase cells using dual-color fluorescence: a demonstration of lineage involvement in polycythemia vera.Fluorescent in situ hybridization has become a useful technique by which chromosomal abnormalities may be shown in interphase cells. We present a dual-fluorescence method whereby a chromosomal and immunophenotypic marker can be visualized simultaneously in the same interphase cell. Two patients with the myeloproliferative disorder polycythemia vera and trisomy for chromosome 8 have been studied using this technique and selective involvement of the myeloid and erythrocyte lineages has been shown by the detection of the trisomy in immunophenotyped cells. Simultaneous analysis of genotype and immunophenotype in individual cells from patients with myeloproliferative disorders or leukemia may help identify the developmental and lineage status of cells in which molecular alterations have resulted in clonal advantage.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/6. der(1)t(1;9): a specific chromosome abnormality in polycythemia vera? Cytogenetic and in situ hybridization studies.Two patients with polycythemia vera and an extra der(1)t(1;9) chromosome are reported. In one patient this was found as the sole abnormality. The other patient originally presented with trisomy 9 but later developed an extra der(1) during the further course of the disease with disapperance of the extra chromosome 9. in situ hybridization studies on this latter patient proved that the centromere of chromosome 1 was involved in the formation of the derivative chromosome.- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |
5/6. Chronic myelogenous leukemia and acute lymphoblastic leukemia occurring in the course of polycythemia vera.We are reporting an unusual case of a 54-year-old woman with polycythemia vera (PV) who developed Ph chromosome positive chronic myelogenous leukemia (CML) 8 years after the initial diagnosis of PV, and terminating in acute lymphoblastic leukemia (ALL), 11 years after the initial diagnosis. Cytogenetic studies revealed a normal female karyotype at the time of diagnosis of PV and the presence of a Ph chromosome at the time of appearance of CML. Southern blot hybridization revealed a bcr rearrangement in both mononuclear cells and granulocytes. The diagnosis of ALL was established on the basis of morphology, positive TdT staining, and monoclonal antibody studies positive for 12, B4, and J5. This case demonstrates the transition of PV into CML, followed by a blastic transformation into acute lymphocytic leukemia. At termination of her disease there were findings compatible with bi-phenotypic leukemia. These findings would suggest that the disease arose in a primitive multipotential stem cell.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/6. polycythemia vera treated with recombinant interferon-alpha 2a: evidence of a selective effect on the malignant clone.We periodically analyzed bone-marrow cytogenetic features in 8 patients belonging to a series of 38 subjects with polycythemia vera (PV), all treated with recombinant interferon-alpha 2a (rIFN-alpha) at a weekly dose of 9,000,000 IU. Six out of these 8 patients never showed any chromosome alterations, while 2 displayed at diagnosis the presence of trisomy 8 in all bone-marrow metaphases. Interestingly enough, in these 2 patients rIFN-alpha treatment was able to induce not only complete hematological response but also the disappearance of trisomy 8, as shown by conventional cytogenetic investigation and fluorescence in situ hybridization performed on bone-marrow cells after 1 year of treatment. This finding indicates that, as previously shown in chronic myeloid leukemia, in PV rIFN-alpha can also eradicate the malignant clone by means of a selective effect on bone-marrow transformed cells.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |