1/20. Three new cases of chromosome 3 rearrangement in bands q21 and q26 with abnormal thrombopoiesis bring further evidence to the existence of a 3q21q26 syndrome.Defects of 3q in bands q21 and q26 have been reported in more than 70 cases of acute nonlymphocytic leukemia (ANLL), myelodysplastic syndrome (MDS), and myeloproliferative disorder (MPD) in blast crisis. In this paper three additional patients are described: patient 1 with refractory anemia with excess of blasts in transformation (RAEB-T) and inv(3)(q21q26), patient 2 with RAEB-T and t(3;3)(q21;q26), and patient 3 with myelofibrosis with myeloid metaplasia (MMM) in blast crisis and inv(3)(q21q26). In addition to 3q rearrangements, monosomy 7 and del(7)(q22q36) were observed in patients 1 and 2, respectively. In the three patients, the most characteristic clinical features were elevated platelet counts, marked hyperplasia with dysplasia of the megakaryocytes, and poor prognosis. Although disturbance of thrombopoiesis was not systematically observed in all patients with t(3;3)(q21;q26), inv(3)(q21q26), and ins or dup(3)(q21 q26), study of the 77 cases reported and of the three cases presented here brings further evidence to the existence of a cytogenetic syndrome involving bands q21 and q26 simultaneously, which represents a subtype of ANLL, MDS, and MPD, characterized by normal or elevated platelet counts, hyperplasia with dysplasia of megakaryocytes, multilineage involvement, young median age of patients with MDS, preferential involvement of women in t(3;3), high incidence of chromosome 7 defects in MDS and ANLL, short duration of the MDS phase, no response to chemotherapy, short survival, and por prognosis.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
2/20. Cytogenetic and molecular studies of the philadelphia translocation in myelodysplastic syndromes. Report of two cases and review of the literature.We report two patients with a myelodysplastic syndrome and the philadelphia (Ph) chromosome. The first patient was a 73-year-old man who was diagnosed as having a chronic myelomonocytic leukemia in combination with features suggestive of a myeloproliferative syndrome. Chromosomal analysis showed a normal karyotype in the majority of cells, mixed with metaphases containing a standard Ph translocation, t(9;22)(q34;q11), as well as a translocation between chromosome 4 and 6: t(4;6)(p15;p12). Southern blot analysis showed breakpoint cluster region rearrangement as observed in classic chronic myeloid leukemia. The second patient was a 63-year-old man with a myelodysplastic syndrome, type refractory anemia. Cytogenetic study of bone marrow cells at the time of diagnosis revealed a normal karyotype: 46,XY. The initial myelodysplastic syndrome evolved to a myeloproliferative phase with progressive leukocytosis and thrombocytosis. During the terminal phase the Ph chromosome was discovered in 100% of the examined cells. We discuss the correlation between MDS and myeloproliferative diseases, the de novo acquisition of the Ph chromosome during the course of a myelodysplastic syndrome, and review the literature.- - - - - - - - - - ranking = 2keywords = leukemia (Clic here for more details about this article) |
3/20. Benign chronic neutropenia with abnormalities involving 16q22, affecting mother and daughter.We report a case of familial, chronic, benign neutropenia in a 17-year-old female showing (1) the spontaneous expression of a heritable rare fragile site at 16q22 and (2) a deletion at the same region. The del(16)(q22), which most likely originated from the fragile site, was the main clonal abnormality detected in the patient's bone marrow cells, whereas a few cells with either del(16)(q22) or fra(16)(q22) were seen in the patient's peripheral blood. Interestingly, the del(16q) was also detected in the patient's uncultured cells, as demonstrated by FISH, excluding an in vitro origin of the del(16q) during culture. The bone marrow was hypocellular with decreased neutrophils and their precursors. Absolute neutrophil counts ranged from (0.62 to 1.24) x 10(9)/L with a median value of 1.02 x 10(9)/L. The patient had a more severe neutropenia than her mother, which correlated with the presence of more cells with del(16q) in the marrow. The patient's mother, who was also diagnosed with neutropenia, revealed only a few cells with the rare fra(16)(q22) in her peripheral blood cells, whereas her bone marrow showed cells with both fra(16)(q22) and del(16)(q22), although the del(16q) was present in only 2/20 cells. Some possible candidate genes contributing to the pathogenesis of the neutropenia are discussed. Chromosome abnormalities involving the 16q22 breakpoint have been observed in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). In this patient, the del(16)(q22) risk factor is unknown for subsequent development of MDS or AML. Another point to consider is the need to determine the origin of a chromosome abnormality, particularly when the clinical picture does not fit the chromosome findings. Although, the observation of a constitutional structural abnormality in a mosaic form is an extremely rare event, it is somewhat different in the case of a fragile site expression, which can, as in this case, be present in some cells and not in others.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
4/20. Acute T-lymphocytic leukemia with Ph1 and 5q-chromosome abnormalities and rearrangements of bcr and TCR-delta genes.Almost all cases of Ph1-positive acute lymphocytic leukemia (ALL) have an immature B-cell phenotype and are CD10-positive. A very rare case of Ph1-positive ALL with T-cell features (T-ALL) is presented. Cytogenetic analyses revealed a clone with a Ph1 chromosome and 5q- at diagnosis, and mosaic clones with an additional complex abnormal karyotype at relapse. dna analysis revealed rearrangement of the breakpoint cluster region (bcr) gene with deletion of the 5' side and of the T-cell receptor (TCR) delta gene, without any rearrangement of other immune-associated genes. From the results of immunophenotypic and genetic analyses, the origin of leukemic cells seemed to be an immature T-cell at a very early stage on T-cell ontogeny.- - - - - - - - - - ranking = 5keywords = leukemia (Clic here for more details about this article) |
5/20. Differential expression of FRA16B in peripheral lymphocytes and bone marrow cells.Expression of the rare fragile site FRA16B in chromosome band 16q22 was studied in bone marrow (BM) cells and peripheral blood lymphocytes (PBLs) from three unrelated subjects. Although FRA16B was detected only in PBLs from two healthy subjects who had been previously treated for non-Hodgkin's lymphoma (NHL), both cell types displayed FRA16B in a patient with chronic myelomonocytic leukemia (CMMoL). This variability in expression could be related to differences in the proliferative status of the cell populations or to differences in gene activity in the fragile site region.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
6/20. Spontaneous chromosome fragility in band 3q21, 11p11, or 11q13 of cultured bone marrow cells from two patients with hematologic disorders.Chromatid gaps and breaks clustering to band 3q21, 11p11, or 11q13 were observed prior to chemotherapy in short-term cultured bone marrow cells from two patients with hematologic disorders, one with acute monoblastic leukemia having 8 as the sole karyotypic abnormality and the other with pernicious anemia having no chromosome abnormality. The mitogen-stimulated peripheral blood lymphocytes of both patients, however, yielded a negligible frequency of chromosome aberrations. Because of no notable history of clastogen exposure in these patients, the observed chromosome fragility is most probably spontaneous, which might be correlated with the patients' physiologic condition at examination, i.e., an unusually low level of folic acid or vitamin B12, both being involved in dna synthesis. Although band 11q13 is known to contain a common fragile site, chromosome fragility in bands 3q21 and 11p11 has not yet been reported in either normal or neoplastic cells. The present findings appear to favor the in vivo expression of chromosome fragility.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
7/20. Heritable rare fragile sites in patients with leukemia and other hematologic disorders.Fragile site studies were performed on a total of 126 patients with leukemia and other hematologic disorders including myelodysplastic syndrome (MDS) and polycythemia vera (PV). Compared with an incidence (6.0%) of heritable rare fragile sites in the healthy population, the frequency was not higher in the patient group (3.2%), as a whole. However, two cases of fra(17)(p12) in MDS appeared fourfold larger than expected for this group of patients. In one case, a homozygous carrier of fra(17)(p12) in PV was also very rarely expected from its population incidence. These findings suggested a possible role of rare fragile sites, at least in the etiology of these preleukemic or myeloproliferative disorders.- - - - - - - - - - ranking = 5keywords = leukemia (Clic here for more details about this article) |
8/20. Heritable fragile sites and cancer: fra(16)(q22) in lymphocytes of an acute nonlymphocytic leukemia patient with inv(16)(p13q22).Fragile site testing was performed on normal peripheral blood lymphocytes from three acute nonlymphocytic leukemia patients who carried inv(16)(p13q22) in malignant cells. Cultures were treated with BrdU, distamycin A, Hoechst 33258, or folic acid deprivation to induce fragile site expression. One patient was found to be a carrier of fra(16)(q22), but the expression was observed only by Hoechst 33258 treatment.- - - - - - - - - - ranking = 5keywords = leukemia (Clic here for more details about this article) |
9/20. Inversion (16)(p13q22) in tumor cells of sigmoid colon.We report on the cytogenetic findings in direct preparations of two tumors of the sigmoid colon. Respectively, they had a near-triploid and a near-tetraploid constitution and relative numerical and other inconstant chromosomal imbalances. The only constant chromosomal structural anomaly apparently was inversion of chromosome #16, inv(16)(p13q22), which was found in all the cells examined. This rearrangement has been found to be associated with a type of acute myelomonocytic leukemia type M4. We suggest that an etiologic clastogenic (and oncogenic) agent responsible for this rearrangement may eventually be the cause of various kinds of malignancy.- - - - - - - - - - ranking = 1keywords = leukemia (Clic here for more details about this article) |
10/20. Translocation X;10 in a case of congenital acute monocytic leukemia.Unusual cytogenetic findings were noted in the leukemic cells from a patient with congenital acute monocytic leukemia (AMol or M5, according to the FAB classification), whereas, the chromosomes of cultured skin fibroblasts were normal. G-banded karyotypes of leukemic cells showed an X-autosome translocation, 46,X,t(X;10)(Xpter q13::10q11.2 qter)(10pter q11.2::Xq28 q13:: Xq28 qter). review of reported cases of acute nonlymphocytic leukemia (ANLL) with rearrangements involving chromosomes #10 or X showed a high frequency of abnormalities of the short arm of #10 in myelomonocytic (M4) and monocytic (M5) leukemias, particularly in patients less than 2-yr-of-age. Although previously reported cases of ANLL in infants are predominantly of these types, the translocation observed in this case is unique. Fragile sites known to exist on chromosomes #10 and X are not associated with neoplasia and, except for Xq27-28, were not at the breakpoints of the case presented. The precise location of a human cellular oncogene recently identified on the x chromosome remains unknown.- - - - - - - - - - ranking = 7keywords = leukemia (Clic here for more details about this article) |
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