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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Translocation (6;9)(p23;q34) is a cytogenetic aberration that can be found in specific subtypes of both acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). This translocation is associated with an unfavourable prognosis. Recently, the genes involved in the t(6;9) were isolated and characterized. Breakpoints in both the dek gene on chromosome 6 and the can gene on chromosome 9 appear to occur in defined regions, which allows us to diagnose this type of leukemia at the molecular level. Moreover, because of the translocation a chimeric dek-can mRNA is formed which, as we show here, is an additional target for diagnosis via cDNA-preparation and the polymerase chain reaction (PCR). We studied 17 patients whose blood cells and/or bone marrow cells showed a t(6;9) with karyotypic analysis. Fourteen patients suffered from AML, one patient had a refractory anemia with excess of blasts in transformation (RAEBt), one patient had an acute myelofibrosis (AMF), and one patient a chronic myeloid leukemia (CML). In nine cases studies at the DNA and RNA levels were possible while in seven cases only the DNA could be analyzed. In one case only RNA was available. Conventional Southern blot analysis showed the presence of rearrangements of both the dek gene and the can gene. In both genes, breakpoints cluster in one intron in the patients investigated. The presence of a consistent chimeric dek-can product after cDNA preparation followed by the PCR was demonstrated. We conclude from our data that the t(6;9) is found in myeloproliferative disorders with typical clinical characteristics. This translocation results in highly consistent abnormalities at the molecular level.
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PMID:The translocation (6;9) (p23;q34) shows consistent rearrangement of two genes and defines a myeloproliferative disorder with specific clinical features. 158 43

The translocation (6;9)(p23;q34) is mainly found in specific subtypes of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The diagnosis of this translocation is not easy since the cytogenetic change is quite subtle. The two genes involved in this translocation were recently isolated and diagnosis at the DNA-level became an additional option. Both the dek gene on chromosome 6 and the can gene on chromosome 9 contain one specific intron where breakpoints of t(6;9) patients were found to cluster. The translocation results in a consistent chimeric dek-can mRNA which is generated from the 6p- derivative. Five centers participated in a study to estimate the incidence of t(6;9) in leukemic patients using conventional Southern blot analysis. Patients (n = 320) with either acute undifferentiated leukemia (AUL), AML, MDS or acute lymphoblastic leukemia (ALL) were screened for rearrangement of the genes involved in this translocation. Four of these 320 patients showed rearrangement of the can gene on chromosome 9, of which one also had a rearranged dek gene on chromosome 6. A further 20 patients were studied with karyotypic aberrations in which either the short arm of chromosome 6 or the long arm of chromosome 9 were specifically involved. Both conventional Southern blot analysis and contour-clamped homogeneous electric field (CHEF) analysis failed to show dek-can rearrangement in any of these patients. The results of our study indicate that the incidence of the t(6;9) is a low as reported based on cytogenetic data and that rearrangement of the dek and can genes is mainly restricted to this specific translocation.
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PMID:Dek-can rearrangement in translocation (6;9)(p23;q34). 160 86

We report here a case of acute nonlymphocytic leukemia evolving from a myelodysplastic syndrome which developed in an elderly man who had received radiation therapy for a prior cancer. Cytogenetic analysis revealed the following karyotype: 47,XY, + 8,t(1;6)(p13;p23). The breakpoints in the translocation are in the regions of the NRAS1 and PIM1 oncogenes on chromosomes 1 and 6, respectively. This translocation has not been previously observed in hematological malignancies.
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PMID:Translocation (1;6)(p12;p23) in ANLL. 230 87

Two patients with acute myelomonocytic leukemia (AML-M4) and a specific chromosomal translocation t(6;9)(p23;q34) are reported and compared to 21 AML patients with the same translocation collected from the literature. Our observation suggest that AML with t(6;9)(p23;q34) is characterized by myelodysplasia, basophilia, and a variety of blast cell morphologies (M1, M2, M4) with a greater proportion of the cases than previously appreciated being examples of acute myelomonocytic leukemia (AML-M4). The consistent association of myelodysplasia provokes the proposal that this subtype of de novo AML is a result of an acute stem cell disorder. The poor outcome with standard AML chemotherapy experienced in this group of relatively young patients necessitates consideration of alternative therapeutic strategies such as early bone marrow transplantation.
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PMID:Acute myelomonocytic leukemia (AML-M4) and translocation t(6;9)(p23);q34): two additional patients with prominent myelodysplasia. 347 96

Two further cases with myeloproliferative disorders (a child with smoldering leukemia and a young male with acute nonlymphocytic leukemia of FAB type M2) and a translocation t(6;9)(p23;q34) are described. Special attention is paid to environmental factors and the early age of onset of patients within the group of leukemias with this specific translocation. In one of our cases a secondary chromosomal anomaly has arisen, which is comparable with another case from the literature.
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PMID:Translocation (6;9)(p23;q34) in smoldering leukemia and acute nonlymphocytic leukemia. 356 80

We have characterized another subset of acute nonlymphocytic leukemia (ANLL) based on the cytogenetic and morphologic findings in a group of nine patients. Five patients had chromosomal analyses performed at the University of Chicago, two patients were studied at the All-Union Cancer Research Center in Moscow, and one patient each was studied at the University of Maryland and at Fairfax Hospital in Fairfax, Virginia. All nine patients had a reciprocal translocation involving the short arm of chromosome 6 and the long arm of chromosome 9 [t(6;9)(p23;q34)]. The patients, four males and five females, ranged in age from 5 to 51 years; the median age of 38 years is lower than that typically seen in ANLL. Only two of eight treated patients entered a complete remission. Classification of bone marrow morphology according to FAB Cooperative Group criteria revealed AML-M1 in one patient, AML-M2 in four, and AMMoL-M4 in three. One patient had refractory anemia with excess blasts (RAEB) which evolved to AML-M2. All bone marrow specimens showed severe myelodysplasia, with Auer rods present in seven of the nine cases. Of note was the particular prominence of bone marrow basophils (greater than 1%) in eight of the nine (89%) patients. Among 160 evaluable patients with ANLL de novo seen at the University of Chicago whose cells lacked a t(6;9), only five (3%) had greater than 1% basophils in the marrow aspirates. It is of interest that the breakpoint in 9q involves the same chromosomal band as that in the t(9;22) observed in chronic myelogenous leukemia (CML), in which increased basophils are a prominent feature. Thus, the association of the t(6;9) with increased bone marrow basophils in ANLL may provide additional insight into the chromosomal location of genes regulating the production and/or maturation of basophils.
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PMID:Increased numbers of marrow basophils may be associated with a t(6;9) in ANLL. 397 50

FLT4 is a recently cloned receptor tyrosine kinase cDNA, which is characterized by seven immunoglobulin-like loops in its extracellular domain. We have previously mapped the FLT4 gene to chromosome segment 5q33-qter using somatic cell hybrids. Here we have refined the localization to band 5q35 by fluorescence in situ hybridization and show that the gene is translocated to chromosomes 2 and 6 in the t(2;5)(p23;q35) and t(5;6)(q35;p21) translocations, respectively, of Ki-I-positive lymphomas, as well as to chromosome 3 in the t(3;5)(q25.1;q34) translocation, which is occasionally found in myelodysplastic syndromes and acute myeloid leukemia. No evidence was obtained for a rearrangement or deregulation of the translocated FLT4 gene. We further show that abundant FLT4 mRNA expression occurs only in erythroid and megakaryoblastoid cell lines among nine leukemia cell lines studied.
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PMID:FLT4 receptor tyrosine kinase gene mapping to chromosome band 5q35 in relation to the t(2;5), t(5;6), and t(3;5) translocations. 768 67

We treated a 16-month-old girl with myelodysplastic syndrome (MDS; refractory anemia with excess of blasts subtype, RAEB by FAB classification) that developed into acute megakaryoblastic leukemia (ANLL-M7). The blast cells were positive for CD41 shown by flow cytometry and for platelet peroxidase by electron microscopy. Cytogenetically, five kinds of abnormal karyotypes were apparent at the initial visit and karyotypic progression (clonal evolution) was also evident. These karyotypes were considered to be derived from the putative original clone, 48,XX, +6, +21. The observed karyotypes were considered 50,XX, +4,add(4)(q31), +6,add(7)(p22),add(10)(q24),add(12)(q11), +20, +21, + mar[karyotype A];48,XX,add(4)(q31), +6,add(10)(q24),add(12)(q11), +21 [karyotype B];48,XX, +6,t(6;13)(p23;q14), +21 [karyotype C];51,XX, +X, t(6;13)(p23;q14), + der(6)t(6;13)(p23;q14), +21, +21, + mar [karyotype D]; and 49,XX, +X, -3,t(6;13)(p23;q14), +der(6)t(6;13)(p23;q14), -12, +21, +21, + mar [karyotype E]. It seems karyotypes B and C were derived from the putative clone; karyotype B developed into karyotype A; and karyotype C developed into karyotype E through karyotype D. After development of ANLL-M7, the cytogenetic study showed a karyotype with further karyotypic progression. The patient was treated with high-dose cytosine arabinoside (HD AraC) followed by allogeneic bone marrow transplantation. Despite intensive care, she died 3 months after the transplantation.
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PMID:Childhood myelodysplastic syndrome with clonal evolution progressing to acute megakaryoblastic leukemia (ANLL-M7). 822 7

A second case of acute myeloid leukemia (AML) with a t(2;4)(p23;q25) as the sole anomaly is reported. Our case had a de novo AML (M2); the case previously described had AML (M2) post-MDS. It is suggested that t(2;4)(p23;q25) is a new, recurrent, but rare anomaly in AML.
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PMID:Translocation (2;4)(p23;q25): an additional case of a new recurrent anomaly in acute myeloid leukemia. 824 96

The clinical, hematological, and cytogenetic data from two young adults with acute myeloid leukemia (AML) FAB type M1 is described. At diagnosis, cytogenetic investigation revealed the presence of the translocation t(6;9)(p23;q34). Bone marrow basophilia was not detected in either patient nor was there any evidence of preceding or underlying myelodysplasia. Both patients achieved complete remission (CR) and one patient remains in CR of over 5 years duration. It is suggested that the presence of basophilia may be associated with the myelodysplasia rather than the chromosome anomaly t(6;9).
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PMID:Translocation t(6;9)(p23;q34) in acute myeloid leukemia without myelodysplasia or basophilia: two cases and a review of the literature. 846 30


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