1/41. Two cases of myeloid disorders and a t(8;12) (q12;p13).BACKGROUND AND OBJECTIVE: Rearrangements of the short arm of chromosome 12 have been described in different hematologic malignancies. Some of these abnormalities showed a rearrangement of the ETV6 gene. We studied the 12p region in one case with a t(8;12)(q12;p13) by fluorescence in situ hybridization (FISH). DESIGN AND methods: We have identified a chromosome translocation, t(8;12)(q12;p13) in two patients with myeloid disorders; one with acute myelogenous leukemia (AML) and one with refractory anemia (RA). FISH studies with specific probes (cosmids and YACs) for the 12p region were used to investigate one case. RESULTS: FISH studies demonstrated hemizygous loss of the ETV6 and CDKN1B regions and two copies of the CCDN2 locus, as a result of the balanced translocation and an additional copy of the der(8). INTERPRETATION AND CONCLUSIONS: Myeloid diseases with t(8;12)(q12;p13) have an interstitial deletion of 12p, including the ETV6 and CDKN1B regions. A duplication of CCDN2 locus can also be found.- - - - - - - - - - ranking = 1keywords = chromosome, deletion (Clic here for more details about this article) |
2/41. Familial-skewed X-chromosome inactivation as a predisposing factor for late-onset X-linked sideroblastic anemia in carrier females.X-linked sideroblastic anemia (XLSA) is caused by mutations in the erythroid-specific 5-aminolevulinic acid synthase (ALAS2) gene. An elderly woman who presented with an acquired sideroblastic anemia is studied. Molecular analysis revealed that she was heterozygous for a missense mutation in the ALAS2 gene, but she expressed only the mutated gene in reticulocytes. Her 2 daughters and a granddaughter were heterozygous for this mutation, had normal hemoglobin levels, and expressed the normal ALAS2 gene in reticulocytes. A grandson with a previous diagnosis of thalassemia intermedia was found to be hemizygous for the ALAS2 mutation. Treatment with pyridoxine completely corrected the anemia both in the proband and her grandson. All women who were analyzed in this family showed skewed X-chromosome inactivation in leukocytes, which indicated a hereditary condition associated with unbalanced lyonization. Because the preferentially active x chromosome carried the mutant ALAS2 allele, acquired skewing in the elderly likely worsened the genetic condition and abolished the normal ALAS2 allele expression in the proband. (blood. 2000;96:4363-4365)- - - - - - - - - - ranking = 2.7074967900375keywords = chromosome (Clic here for more details about this article) |
3/41. Familial partial monosomy 7 and myelodysplasia: different parental origin of the monosomy 7 suggests action of a mutator gene.Two sisters are reported, both with a myelodysplastic syndrome (MDS) associated with partial monosomy 7. A trisomy 8 was also present in one of them, who later developed an acute myeloid leukemia (AML) of the M0 FAB-type and died, whereas the other died with no evolution into AML. Besides FISH studies, microsatellite analysis was performed on both sisters to gather information on the parental origin of the chromosome 7 involved in partial monosomy and of the extra chromosome 8. The chromosomes 7 involved were of different parental origin in the two sisters, thus confirming that familial monosomy 7 is not explained by a germ-line mutation of a putative tumor-suppressor gene. Similar results were obtained in two other families out of the 12 reported in the literature. Noteworthy is the association with a mendelian disease in 3 out of 12 monosomy 7 families, which suggest that a mutator gene, capable of inducing both karyotype instability and a mendelian disorder, might act to induce chromosome 7 anomalies in the marrow. We postulate that, in fact, an inherited mutation in any of a group of mutator genes causes familial monosomy 7 also in the absence of a recognized mendelian disease, and that marrow chromosome 7 anomalies, in turn, lead to MDS/AML.- - - - - - - - - - ranking = 159.62646472186keywords = monosomy, chromosome (Clic here for more details about this article) |
4/41. Hypogammaglobulinemia and reduced numbers of B-cells in children with myelodysplastic syndrome.BACKGROUND: Immunodeficiency in pediatric patients with myelodysplastic syndrome (MDS) has not been described. We report the clinical course of three children with MDS, hypogammaglobulinemia, and reduced numbers of B-cells and B-cell precursors. OBSERVATIONS: Three patients with recurrent infection who were younger than 1-year-old had MDS of the refractory anemia (RA) subtype diagnosed. All had reduced numbers of circulating B-cells and hypogammaglobulinemia. In two patients, cytogenetic studies revealed a monosomy 7 karyotype and bone marrow studies showed decreased numbers of CD34 progenitor cells and CD 19 B-cells. Both patients had prolonged courses (7 yrs 10 mos and 6 yrs 9 mos) characterized by recurrent infection and slowly progressive pancytopenia. Both received allogeneic bone marrow transplantation (BMT). The third patient had normal cytogenetic studies and a normal number of CD34 progenitors but decreased CD19 B-cells in the bone marrow. She had a stable course with refractory anemia over the course of 7 years. CONCLUSIONS: Pediatric patients with MDS may have hypogammaglobulinemia and reduced numbers of B-cells. These findings do not preclude a relatively stable and prolonged clinical course. Children with newly diagnosed MDS should have an immunologic evaluation in addition to their hematologic assessment.- - - - - - - - - - ranking = 12.105401338218keywords = monosomy (Clic here for more details about this article) |
5/41. Secondary acute myeloid leukaemia with monosomy 7 in identical adult twins.We report the development of secondary acute myeloid leukaemia (AML) with monosomy 7 in identical twins, both at the age of 52 years. In the first twin, induction therapy resulted in complete remission (CR). At relapse 9 months later monosomy 7 was found. The patient died of sepsis 11 months after diagnosis. The other twin presented with leucopenia and thrombocytopenia and refractory anaemia (RA) was diagnosed. During follow-up, fluorescence in situ hybridization analysis demonstrated a monosomy 7 in 11% of the cells. Twenty-eight months following diagnosis the patient progressed to RA with excess blasts in transformation and induction chemotherapy was initiated without achieving CR. Three months later an allogeneic stem cell transplantation from a niece was performed, resulting in CR of the secondary AML.- - - - - - - - - - ranking = 84.737809367525keywords = monosomy (Clic here for more details about this article) |
6/41. Refractory anemia with ring sideroblasts associated with i(17q) and mutation of the TP53 gene.A patient with a myelodysplastic syndrome ([MDS], i.e., refractory anemia with ring sideroblasts [RARS]) and a rapidly fatal clinical course is presented. A cytogenetic analysis showed an isochromosome 17q as a sole abnormality in all metaphases. An association between RARS and i(17q) has not been reported. Furthermore, a mutation of the remaining TP53 gene in exon 6 was evidenced by a single strand conformation polymorphism technique. This unique case illustrates heterogeneity of phenotypic expression of a stem cell disorder in MDS and indicates precaution in classifying hematologic syndromes especially when morphology is correlated with specific cytogenetic changes.- - - - - - - - - - ranking = 0.45124946500626keywords = chromosome (Clic here for more details about this article) |
7/41. A unique clone involving multiple structural chromosome rearrangements in a myelodysplastic syndrome case.In a young female patient presenting with a myelodysplastic syndrome (MDS), a unique clone involving six structural chromosome rearrangements was identified using G-banding and molecular cytogenetic techniques. Fifty GTG-banded metaphases from bone marrow were initially analyzed and all metaphases contained all of the six structural chromosome rearrangements. To further define the GTG-banded karyotype, a series of fluorescence in situ hybridization and primed in situ labeling experiments were performed and the karyotype was then characterized as: 46,XX,r(5)(p13q13),der(20)t(5;20),dup(11)(p11.2p15), r(11)(p15q25),del(13)(q14),idic(22)(p11). The patient quickly progressed to acute nonlymphocytic leukemia three months after the diagnosis and died of a hemorrhage in the brain parenchyma two months later. In this case, the multiple structural chromosome rearrangements conferred an obvious cellular proliferative advantage and indicated a very poor prognosis. Considering that multiple chromosome abnormalities associated with MDS transformation are often polyclonal, this unique clone involving six structural chromosome rearrangements make our case highly unusual.- - - - - - - - - - ranking = 4.0612451850563keywords = chromosome (Clic here for more details about this article) |
8/41. One allele deletion of the RB1 gene in a case of refractory anemia with del(13)(q12q14): a fluorescence in situ hybridization study of the RB1 gene.The tumor suppressor gene RB1 is known to be located on chromosome band 13q14. We investigated the involvement of the RB1 gene in a case of refractory anemia with del(13)(q12q14) by florescence in situ hybridization (FISH) analysis using the RB1 locus (13q14) dna probe. bone marrow cells derived from this patient exhibited a single signal of the RB1 gene in 58 of 100 bone marrow cells, as determined by interphase FISH analysis. Hematopoietic colony-forming assays showed that the absolute number of erythroid, myeloid, and mixed colonies was comparable to that of normal subjects. FISH analysis of selected colonies revealed that only a single signal for the RB1 gene was detected in five of five granulocyte macrophage-colony-forming units (CFUs), four of five erythroid burst-forming units, and two of four mixed CFUs (total 11/14: 78.6%). Thus, the majority of hematopoietic progenitor cells lacked one allele of the RB1 gene, suggesting that in this particular case the RB1 gene played an important role in abnormal hematopoiesis.- - - - - - - - - - ranking = 0.8412537449562keywords = chromosome, deletion (Clic here for more details about this article) |
9/41. Acute leukemia with t(1;3)(p36;q21), evolution to t(1;3)(p36;q21), t(14;17)(q32;q21), and loss of red cell A and Le(b) antigens.At transformation of refractory anemia with ring sideroblasts to acute nonlymphocytic leukemia (ANLL) the bone marrow cells of a 75-year-old woman showed three different karyotypes, i.e., 46,XX,46,XX,t(1;3)(p36;q21) and 46,XX,t(1;3)(p36;q21),t(14;17)(q32;q21). She received no antileukemic therapy, and 1 year later, all her bone marrow cells were t(1;3)(p36;q21),t(14;17)(q32;q21). In association with the onset and first 11 months of ANLL, the platelet count increased 10-fold to a peak of 750 x 10(9)/L, providing further evidence that the t(1;3)(p36;q21) translocation causes stimulation of thrombopoiesis. Six months after transformation, her red cells showed reduced expression of A and Leb antigens. serum alpha-n-3-acetylgalactosaminyl transferase (blood group A transferase) and red cell adenylate kinase were both reduced. The genes for both these substances are at 9q34, which suggests an abnormality here, although cytogenetically chromosome 9 appeared normal. This is the first case with t(1;3)(p36;q21) to show concurrent loss of red cell antigens and the first report detailing the course of untreated ANLL with t(1;3)(p36;q21).- - - - - - - - - - ranking = 0.45124946500626keywords = chromosome (Clic here for more details about this article) |
10/41. Protein 4.1 deficiency and deletion of chromosome 20q are associated with acquired elliptocytosis in myelodysplastic syndrome.We report a case of myelodysplastic syndrome (MDS), associated with prominent elliptocytosis. A 66-year-old male presented with peripheral pancytopenia, and was diagnosed with MDS [refractory anaemia (RA)]. Apart from marked elliptocytosis, dyshaematopoietic features were not evident in his peripheral blood or hypercellular bone marrow. After 18 months, he had progressed to RA with excess blasts in transformation. Analysis of red blood cell membrane proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a reduced quantity of protein 4.1 (30% of control). Deletion of chromosome 20q was identified by conventional cytogenetic analysis and fluorescence in situ hybridization. Marked elliptocytosis, persistent for more than 17 months, decreased strikingly after chemotherapy with idarubicin and Ara-C. These findings suggest that acquired elliptocytosis occurred as an unusual morphological feature of MDS, associated with abnormalities of protein 4.1 and chromosome 20q.- - - - - - - - - - ranking = 3.0975010699875keywords = chromosome, deletion (Clic here for more details about this article) |
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