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Tang Z, Toruner GA, Tang G, Cameron Yin C, Wang W, Hu S, Thakral B, Wang SA, Miranda RN, Khoury JD, Medeiros LJ. Chronic myeloid leukemia with insertion-derived BCR-ABL1 fusion: redefining complex chromosomal abnormalities by correlation of FISH and karyotype predicts prognosis. Mod Pathol 2020; 33:2035-2045. [PMID: 32404952 DOI: 10.1038/s41379-020-0564-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/24/2020] [Accepted: 04/24/2020] [Indexed: 12/29/2022]
Abstract
Chromosomal insertion-derived BCR-ABL1 fusion is rare and mostly cryptic in chronic myeloid leukemia (CML). Most of these cases present a normal karyotype, and their risk and/or prognostic category are uncertain. We searched our database and identified 41 CML patients (20 M/21 F, median age: 47 years, range 12-78 years) with insertion-derived BCR-ABL1 confirmed by various FISH techniques: 31 in chronic phase, 1 in accelerated phase, and 9 in blast phase at time of diagnosis. Conventional cytogenetics analysis showed a normal karyotype (n = 19); abnormal karyotype with morphologically normal chromosomes 9 and 22 (n = 5); apparent ins(9;22) (n = 2) and abnormal karyotype with apparent abnormal chromosomes 9, der(9) and/or 22, der(22) (n = 15). The locations of insertion-derived BCR-ABL1 were identified on chromosome 22 (68.3%), 9 (29.3%), and 19 (2.4%). Complex chromosomal abnormalities were often overlooked by conventional cytogenetics but identified by FISH tests in many cases. After a median follow-up of 58 months (range 1-242 months), 11 patients died, and 3 lost contact, while the others achieved different cytogenetic/molecular responses. The locations of BCR-ABL1 (der(22) vs. non-der(22)) and the karyotype results (complex karyotype vs. noncomplex karyotype) by conventional cytogenetics were not associated with overall survival in this cohort. However, redefining the complexity of chromosomal abnormality by correlating karyotype and FISH findings, CML cases with simple chromosomal abnormalities had a more favorable overall survival than that with complex chromosomal abnormalities. We conclude that insertion-derived BCR-ABL1 fusions often involve complex chromosomal abnormalities which are overlooked by conventional cytogenetics, but can be identified by one or more FISH tests. We also suggest that the traditional cytogenetic response criteria may not apply in these patients, and the complexity of chromosomal abnormalities redefined by correlating karyotype and FISH findings can plays a role in stratifying patients into more suitable risk groups for predicting prognosis. (Word count: 292).
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Affiliation(s)
- Zhenya Tang
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
| | - Gokce A Toruner
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Guilin Tang
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - C Cameron Yin
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Wei Wang
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Shimin Hu
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Beenu Thakral
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Sa A Wang
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Roberto N Miranda
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Joseph D Khoury
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - L Jeffrey Medeiros
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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Ratajczak B, Gniot M, Przybylowicz-Chalecka A, Czerwinska-Rybak J, Komarnicki M, Lewandowski K, Jarmuz-Szymczak M. Characterization and significance of the Philadelphia negative/ BCR-ABL1 positive rearrangement or masked Philadelphia translocation in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors: a single-center study. Leuk Lymphoma 2019; 61:189-193. [PMID: 31389273 DOI: 10.1080/10428194.2019.1648807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Blazej Ratajczak
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland
| | - Michal Gniot
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland
| | | | - Joanna Czerwinska-Rybak
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland
| | - Mieczyslaw Komarnicki
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland
| | - Krzysztof Lewandowski
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland
| | - Malgorzata Jarmuz-Szymczak
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland.,Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
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Soliman DS, Amer AM, Mudawi D, Al-Sabbagh Z, Alkuwari E, Al-Sabbagh A, Ibrahim F, Yassin MA. Chronic Myeloid Leukemia with cryptic Philadelphia translocation and extramedullary B-lymphoid blast phase as an initial presentation. ACTA BIO-MEDICA : ATENEI PARMENSIS 2018; 89:38-44. [PMID: 29633732 PMCID: PMC6179102 DOI: 10.23750/abm.v89i3-s.7219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 11/25/2022]
Abstract
Chronic Myeloid Leukemia (CML) is a clonal myeloproliferative neoplasm (MPN) characterized by the presence of a reciprocal translocation between the long arms of chromosomes 9 and 22, t(9;22)(q34:q11), resulting in fusion of the break point cluster region (BCR) with the ABL gene, which forms an oncogene, the transcript of which is an oncoprotein with a tyrosine kinase function. In the great majority of CML; BCR/ABL1 is cytogenetically visualized as t(9;22); giving rise to the Ph chromosome, harboring the chimeric gene. Cryptic or masked translocations occur in 2-10% patients with no evidence for the BCR/ABL rearrangement by conventional cytogenetics but are positive by Fluorescence in Situ Hybridization (FISH) and/or reverse transcriptase polymerase chain reaction (RT-PCR). These patients are described as Philadelphia negative (Ph negative) BCR/ABL1-positive CML with the chimeric gene present on the derivative chromosome 22, as in most CML cases, or alternatively on the derivative 9 in rare occasions. In the majority of cases, CML is diagnosed in the chronic phase; it is less frequently diagnosed in accelerated crises, and occasionally, its initial presentation is as acute leukemia. The prevalence of extramedullary blast phase (BP) has been reported to be 7-17% in patients with BP. Surprisingly, no extramedullary blast crises of B-lymphoid lineage have been reported before among cases of CML as the initial presentation. We report an adult male diagnosed as CML-chronic phase when he was shortly presented with treatment-naive extramedullary B-lymphoid blast crises involving multiple lymph nodes, with no features of acceleration or blast crises in the peripheral blood (PB) and bone marrow (BM). In addition the patient had variant/cryptic Philadelphia translocation. This is the first report of CML, on the best of our knowledge, with extramedullary B-lymphoid blast phase, as initial presentation, that showed a cryptic Ph translocation. (www.actabiomedica.it)
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Affiliation(s)
- Dina S Soliman
- Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha,Qatar.
| | - Aliaa M Amer
- Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha,Qatar.
| | - Deena Mudawi
- Department of Hematology and Medical Oncology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha, Qatar.
| | - Zafar Al-Sabbagh
- Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha,Qatar.
| | - Einas Alkuwari
- Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha,Qatar.
| | - Ahmad Al-Sabbagh
- Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha,Qatar.
| | - Feryal Ibrahim
- Department of Laboratory Medicine and Pathology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha,Qatar.
| | - Mohamed A Yassin
- Department of Hematology and Medical Oncology, National Center for Cancer Care and Research, Hamad Medical Corporation, Doha, Qatar.
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Cryptic BCR-ABL fusion gene as variant rearrangement in chronic myeloid leukemia: molecular cytogenetic characterization and influence on TKIs therapy. Oncotarget 2018; 8:29906-29913. [PMID: 28404889 PMCID: PMC5444712 DOI: 10.18632/oncotarget.15369] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/16/2017] [Indexed: 11/29/2022] Open
Abstract
At diagnosis, about 5% of Chronic Myeloid Leukemia (CML) patients lacks Philadelphia chromosome (Ph), despite the presence of the BCR/ABL rearrangement. Two mechanisms have been proposed about the occurrence of this rearrangement: the first one is a cryptic insertion between chromosomes 9 and 22; the second one involves two sequential translocations: a classic t(9;22) followed by a reverse translocation, which reconstitutes the normal morphology of the partner chromosomes. Out of 398 newly diagnosed CML patients, we selected 12 Ph-negative cases. Six Ph-negative patients treated with tyrosine kinase inhibitors (TKIs) were characterized, in order to study the mechanisms leading to the rearrangement and the eventual correlation with prognosis in treatment with TKIs. FISH analysis revealed cryptic insertion in 5 patients and classic translocation in the last one. In more detail, we observed 4 different patterns of rearrangement, suggesting high genetic heterogeneity of these patients. In our cases, the BCR/ABL rearrangement mapped more frequently on 9q34 region than on 22q11 region, in contrast to previous reports. Four patients, with low Sokal risk, achieved Complete Cytogenetic Response and/or Major Molecular Response after TKIs therapy. Therapy resistance was observed in one patient with duplication of BCR/ABL rearrangement and in another one with high risk. Even if the number patient is inevitably low, we can confirm that the rare Ph-negative CML patients do not constitute a “warning” category, meanwhile the presence of further cytogenetic abnormalities remains an adverse prognostic factor even in TKI era.
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Molica M, Massaro F, Breccia M. Diagnostic and prognostic cytogenetics of chronic myeloid leukaemia: an update. Expert Rev Mol Diagn 2017; 17:1001-1008. [PMID: 28930482 DOI: 10.1080/14737159.2017.1383156] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Despite the advent of molecular assessment, banding cytogenetics and fluorescence in situ hybridization (FISH) still have a significant role in diagnostic and prognostic approaches to chronic myeloid leukaemia (CML). Area covered: At diagnosis and during treatment with tyrosine kinase inhibitors (TKIs), cytogenetics is used to detect the Philadelphia chromosome, with its typical translocation t(9;22)(q34;q11.2), and any additional or other chromosomal aberrations (ACAs and OCAs) that may arise in 5-10% of cases, the latter associated to transformation of the disease in blast phases. In this review, the potential role of banding cytogenetics and FISH is discussed through a review of published papers on the prognostic impact of these tools in CML treatment and monitoring. Expert commentary: Cytogenetic techniques, including banding cytogenetics and FISH, continue to maintain a crucial role in CML monitoring. At diagnosis and after 3 months of therapy, banding cytogenetics will continue to be an essential test to perform, but it will become redundant after the achievement of a major molecular response (MMR) assessed with molecular techniques. FISH analysis maintains its usefulness in monitoring the response to TKIs only in special situations.
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Affiliation(s)
- Matteo Molica
- a Hematology, Department of Cellular Biotechnologies and Hematology , Sapienza University , Rome , Italy
| | - Fulvio Massaro
- a Hematology, Department of Cellular Biotechnologies and Hematology , Sapienza University , Rome , Italy
| | - Massimo Breccia
- a Hematology, Department of Cellular Biotechnologies and Hematology , Sapienza University , Rome , Italy
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Chen L, Wu Y, You Y, Xiao M, Yao Y, Li W. A novel e8a2 BCR-ABL1 intronic fusion through insertion of a chromosome 22 BCR gene fragment into chromosome 9 in an atypical Philadelphia (Ph) chromosome chronic myeloid leukemia patient. Leuk Lymphoma 2016; 57:2930-2933. [PMID: 27118564 DOI: 10.3109/10428194.2016.1173211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Lifeng Chen
- a Department of Hematology , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , Hubei Province , P.R. China
| | - Yaohui Wu
- a Department of Hematology , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , Hubei Province , P.R. China
| | - Yong You
- a Department of Hematology , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , Hubei Province , P.R. China
| | - Min Xiao
- b Department of Hematology , Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , Hubei Province , P.R. China
| | - Ye Yao
- c Department of Radiation Oncology and Medical Oncology , Zhongnan Hospital, Wuhan University , Wuhan , Hubei Province , P.R. China.,d Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital , Wuhan University , Wuhan , Hubei Province , P.R. China
| | - Weiming Li
- a Department of Hematology , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , Hubei Province , P.R. China
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Wafa A, Almedani S, Liehr T, Al-Achkar W. Masked inv dup(22)(q11.23), tetrasomy 8 and trisomy 19 in a blast crisis-chronic myeloid leukemia after interrupted Imatinib-treatment. Mol Cytogenet 2015; 8:98. [PMID: 26705423 PMCID: PMC4690327 DOI: 10.1186/s13039-015-0204-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 12/17/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The Philadelphia (Ph) chromosome, or derivative chromosome 22 [der(22)], is a product of the reciprocal translocation t(9;22). It is the hallmark of chronic myelogenous leukemia (CML). It results in juxtaposition of the 5' part of the BCR gene on chromosome 22 to the 3' part of the ABL1 gene on chromosome 9. During CML progression 60-80 % of the cases acquire additional genetic changes. Blast crisis (BC) is characterized by the rapid expansion of a population of differentiation arrested blast cells (myeloid or lymphoid cells population), often presenting with secondary chromosomal abnormalities. Here we report an unusual CML-BC case with acquired secondary chromosomal aberrations observed after the patient had to interrupt a successful Imatinib treatment for overall 16 months. CASE PRESENTATION A complete cytogenetic and molecular cytogenetic analysis were performed and application of molecular genetic methods such as reverse transcription polymerase chain reaction (RT-PCR) finally characterized a complex karyotype including an inv dup(22)(q11.23), tetrasomy 8 and trisomy 19. CONCLUSIONS Here we report the first case of a BC after successfully initiated and suddenly interrupted Imatinib treatment. Changes present after such an instant indicate for a rapid progression after Imatinib is no longer suppressing the disease.
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Affiliation(s)
- Abdulsamad Wafa
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission, Human Genetics Division, P.O. Box 6091, Damascus, Syria
| | - Suher Almedani
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission, Human Genetics Division, P.O. Box 6091, Damascus, Syria
| | - Thomas Liehr
- Jena University Hospital, Institute of Human Genetics, Jena, Germany
| | - Walid Al-Achkar
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission, Human Genetics Division, P.O. Box 6091, Damascus, Syria
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Cattaneo D, Morotti D, Bucelli C, Cannone M, Zappa M, Guerneri S, Iurlo A. Comprehensive Molecular Analyses in a Case of Masked Philadelphia Chronic Myeloid Leukemia. Cytogenet Genome Res 2015; 147:35-40. [PMID: 26636412 DOI: 10.1159/000442039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2015] [Indexed: 11/19/2022] Open
Abstract
Here, we report the case of an 80-year-old woman with masked Philadelphia chronic myeloid leukemia (Ph CML). At diagnosis, qualitative PCR demonstrated the presence of a typical e14a2 configuration, and chromosome analysis showed an apparently normal female karyotype. However, FISH with BCR-ABL1 dual fusion probes gave a positive signal in 152/200 analyzed nuclei, with the fusion signal detected on the long arm of a cytogenetically normal chromosome 9. Using locus-specific probes for chromosome 9 and 22 telomeres, a third chromosome involvement was excluded. Furthermore, microarray analysis from the same specimens showed a normal result. Due to a high Charlson Comorbidity Index, the patient was treated with a reduced dose of imatinib, achieving a rapid hematological response after 1 month. However, after 6 months of imatinib therapy, she had to be considered as warning (Ph+ 26.5%, BCR-ABL1 >1%) according to the European LeukemiaNet 2013 recommendations. In conclusion, we confirmed the importance of a combination of cytogenetic and molecular techniques for the diagnosis and therapy monitoring of masked Ph CML, but, different from what has been reported in the literature so far, we cannot completely exclude the fact that the unusual cytogenetic pattern of this patient may have negatively influenced her response to tyrosine kinase inhibitor therapy.
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Affiliation(s)
- Daniele Cattaneo
- Oncohematology Division, IRCCS Ca' Granda - Maggiore Policlinico Hospital Foundation, Milan, Italy
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Bennour A, Saad A, Sennana H. Chronic myeloid leukemia: Relevance of cytogenetic and molecular assays. Crit Rev Oncol Hematol 2015; 97:263-74. [PMID: 26412717 DOI: 10.1016/j.critrevonc.2015.08.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 07/07/2015] [Accepted: 08/24/2015] [Indexed: 12/12/2022] Open
Abstract
Chronic myeloid leukemia (CML) is the prototype cytogenetic malignancy. Even before the development of basic G- and R-banding techniques, CML was found to be associated with a persistent chromosomal abnormality, the Philadelphia (Ph) chromosome. Banding technology later showed the marker chromosome to be a translocation between the breakpoint cluster region (BCR) on chromosome 22q11.2 and the Abelson proto-oncogene (ABL) on chromosome 9q34. Further advances in cytogenetic and molecular biology have also contributed to the understanding, diagnosis, and treatment of CML. Fluorescent in situ hybridization (FISH) has revealed cryptic translocations in most cases of Ph-negative CML. Additional rare chromosomal variant translocations have been discovered as well. The understanding of cytogenetic and molecular physiopathology of CML has led to the use of tyrosine kinase inhibitors as treatment for this disease with spectacular success. Over the 40 years since being identified as the first cytogenetic disease, CML has become the greatest success in translating the basic science of oncology into the treatment of patients with cancer. In this review we will not only summarize the biology of CML, recent progress in the delineation of mechanisms and treatment strategies, but also we will discuss the laboratory tools used for diagnosing CML, for monitoring during treatment and for revealing point mutations and additional chromosomal abnormalities. In doing so, we will describe in detail our individual research on CML, identifying why and how these tests were performed to help to explain CML subgroups and clinical significance of additional chromosomal abnormalities.
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Affiliation(s)
- Ayda Bennour
- Department of Cytogenetics, Molecular Genetics and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia.
| | - Ali Saad
- Department of Cytogenetics, Molecular Genetics and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia
| | - Halima Sennana
- Department of Cytogenetics, Molecular Genetics and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia
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Shao L, Miller S, Keller-Ramey J, Zhang Y, Roulston D. Cytogenetic, fluorescence in situ hybridization, and genomic array characterization of chronic myeloid leukemia with cryptic BCR-ABL1 fusions. Cancer Genet 2015; 208:396-403. [DOI: 10.1016/j.cancergen.2015.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 04/03/2015] [Accepted: 04/06/2015] [Indexed: 10/23/2022]
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Czuchlewski DR, Farzanmehr H, Robinett S, Haines S, Reichard KK. t(9;22)(q34;q11.2) is a recurrent constitutional non-Robertsonian translocation and a rare cytogenetic mimic of chronic myeloid leukemia. Cancer Genet 2012; 204:572-6. [PMID: 22137489 DOI: 10.1016/j.cancergen.2011.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/14/2011] [Accepted: 10/17/2011] [Indexed: 01/26/2023]
Abstract
The diagnosis of hematologic malignancy can be greatly aided by the detection of a cytogenetic abnormality. However, care must be taken to ensure that constitutional chromosomal abnormalities are not misattributed to a putative population of malignant cells. Here we present an unusual case in which a constitutional balanced t(9;22)(q34;q11.2) cytogenetically mimicked the acquired, t(9;22)(q34;q11.2), that is characteristic of chronic myeloid leukemia. Of special note, fluorescence in situ hybridization (FISH) analysis for this constitutional translocation (9;22)(q34;q11.2) using standard probes for BCR and ABL1 resulted in an abnormal pattern that was potentially misinterpretable as a BCR-ABL1 fusion. This is the first reported FISH analysis of a constitutional t(9;22)(q34;q11.2), and overall only the second report of such an abnormality. In light of the isolated prior report, our case also suggests that the constitutional t(9;22)(q34;q11.2) is one of the very few recurrent constitutional non-Robertsonian translocations described in humans. Our case underscores the necessity of complete clinical and laboratory correlation to avoid misdiagnosis of myeloid malignancy in the setting of rare constitutional cytogenetic abnormalities.
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Bennour A, Bellâaj H, Ben Youssef Y, Elloumi M, Khelif A, Saad A, Sennana H. Molecular cytogenetic characterization of Philadelphia-negative rearrangements in chronic myeloid leukemia patients. J Cancer Res Clin Oncol 2011; 137:1329-36. [PMID: 21739181 DOI: 10.1007/s00432-011-1002-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 06/27/2011] [Indexed: 01/13/2023]
Abstract
BACKGROUND The BCR/ABL gene rearrangement is generated by a reciprocal translocation t(9;22)(q34;q11) in chronic myeloid leukemia (CML) patients. In most cases, it is cytogenetically visualized by the Philadelphia (Ph) chromosome. About 5-10% of CML patients lack cytogenetic evidence of the Ph translocation but show BCR/ABL fusion by fluorescence in situ hybridization (FISH) or reverse transcriptase-polymerase chain reaction (RT-PCR). Deletions around the breakpoints on derivative chromosome 9 including 5'ABL and 3'BCR sequences occur in 10-15% of Ph-positive CML patients and are thought to have prognostic significance. METHODS We explored cryptic rearrangements involving chromosomes 9 and 22 in 3 CML patients with an apparently normal bone marrow karyotypes using multiplex RT-PCR and FISH with commercial and home-brew probes. RESULTS The BCR/ABL fusion transcripts were detected by RT-PCR. Using commercial FISH probes, the BCR/ABL fusion gene was found on chromosome 22 in two patients and on chromosome 9 in one patient. Consecutive FISH assays clarified the mechanism of the masked Ph chromosome: in the 3 patients, Ph rearrangement resulted from double mechanism consisting in standard translocation t(9;22)(q34;q11) followed by a second reversed translocation t(9;22)(q34;q11). One patient achieved major cytogenetic response after 6 months of imatinib therapy, and one patient had successful bone marrow transplant. CONCLUSIONS In this study, we have characterized three Ph-negative CML patients with cryptic BCR/ABL rearrangement generated after an uncommon mechanism involving two sequential translocations and confirm that the BCR/ABL hybrid gene may be located on other sites than 22q11. Ph-negative CML patients with BCR/ABL fusion gene have the same prognosis as patients with classical t(9;22).
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Affiliation(s)
- Ayda Bennour
- Department of Cytogenetics, Molecular Genetics and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia.
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13
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Shibata Y, Malhotra A, Dutta A. Detection of DNA fusion junctions for BCR-ABL translocations by Anchored ChromPET. Genome Med 2010; 2:70. [PMID: 20860819 PMCID: PMC3092121 DOI: 10.1186/gm191] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 06/09/2010] [Accepted: 09/22/2010] [Indexed: 12/13/2022] Open
Abstract
Anchored ChromPET, a technique to capture and interrogate targeted sequences in the genome, has been developed to identify chromosomal aberrations and define breakpoints. Using this method, we could define the BCR-ABL1 translocation DNA breakpoint to a base-pair resolution in Philadelphia chromosome-positive samples. This DNA-based method is highly sensitive and can detect the fusion junction using samples from which it is hard to obtain RNA or cells where the RNA expression has been silenced.
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Affiliation(s)
- Yoshiyuki Shibata
- Department of Biochemistry and Molecular Genetics, University of Virginia, School of Medicine, 1300 Jefferson Pk Ave, Charlottesville, VA 22908-0733, USA.
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Virgili A, Brazma D, Reid AG, Howard-Reeves J, Valgañón M, Chanalaris A, De Melo VA, Marin D, Apperley JF, Grace C, Nacheva EP. FISH mapping of Philadelphia negative BCR/ABL1 positive CML. Mol Cytogenet 2008; 1:14. [PMID: 18638369 PMCID: PMC2500019 DOI: 10.1186/1755-8166-1-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 07/18/2008] [Indexed: 12/12/2022] Open
Abstract
Background Chronic myeloid leukaemia (CML) is a haematopoietic stem cell disorder, almost always characterized by the presence of the Philadelphia chromosome (Ph), usually due to t(9;22)(q34;q11) or its variants. The Ph results in the formation of the BCR/ABL1 fusion gene, which is a constitutively activated tyrosine kinase. Around 1% of CML patients appear to have a Ph negative karyotype but carry a cryptic BCR/ABL1 fusion that can be located by fluorescence in situ hybridisation (FISH) at chromosome 22q11, 9q34 or a third chromosome. Here we present FISH mapping data of BCR and ABL1 flanking regions and associated chromosomal rearrangements in 9 Ph negative BCR/ABL1 positive CML patients plus the cell line CML-T1. Results BCR/ABL1 was located at 9q34 in 3 patients, 22q11 in 5 patients and CML-T1 and 22p11 in 1 patient. In 3 of 6 cases with the fusion at 22q11 a distal breakpoint cluster was found within a 280 Kb region containing the RAPGEF1 gene, while in another patient and the CML-T1 the distal breakpoint fell within a single BAC clone containing the 3' RXRA gene. Two cases had a duplication of the masked Ph while genomic deletions of the flanking regions were identified in 3 cases. Even more complex rearrangements were found in 3 further cases. Conclusion BCR/ABL1 formation resulted from a direct insertion (one step mechanism) in 6 patients and CML-T1, while in 3 patients the fusion gene originated from a sequence of rearrangements (multiple steps). The presence of different rearrangements of both 9q34 and 22q11 regions highlights the genetic heterogeneity of this subgroup of CML. Future studies should be performed to confirm the presence of true breakpoint hot spots and assess their implications in Ph negative BCR/ABL1 positive CML.
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Affiliation(s)
- Anna Virgili
- Molecular Cytogenetics, Academic Haematology, Royal Free and UCL Medical School, Rowland Hill Street, London, NW3 2PF, UK.
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Bennour A, Sennana H, Laatiri MA, Khelif A, Saad A. A masked BCR/ABL rearrangement in a case of chronic myeloid leukemia with translocation t(3;9)(p14;q34). ACTA ACUST UNITED AC 2008; 181:72-4. [DOI: 10.1016/j.cancergencyto.2007.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2007] [Revised: 11/19/2007] [Accepted: 11/20/2007] [Indexed: 10/22/2022]
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Aliano S, Cirmena G, Garuti A, Fugazza G, Bruzzone R, Rocco I, Malacarne M, Ballestrero A, Sessarego M. HMGA2 overexpression in polycythemia vera with t(12;21)(q14;q22). ACTA ACUST UNITED AC 2007; 177:115-9. [PMID: 17854665 DOI: 10.1016/j.cancergencyto.2007.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 05/08/2007] [Accepted: 05/15/2007] [Indexed: 11/20/2022]
Abstract
Chromosomal translocations involving the 12q14 band are rarely detected in hematological disorders, and are usually correlated with HMGA2 gene expression. HMGA2 is highly expressed during embryonic cell growth and differentiation, and regulates transcription and chromatin organization, but is rarely detectable in adult tissues. We describe a case of polycythemia vera with a t(12;21)(q14;q22). The 12q14 breakpoint was characterized by fluorescence in situ hybridization analysis using the bacterial artificial chromosome RP11-366L20 containing 3' sequences of the HMGA2 gene. Qualitative and quantitative polymerase chain reaction showed the presence of high levels of HMGA2 gene expression, which were temporarily reduced with hydroxyurea therapy. The present case confirms that involvement of the 12q14 band may be associated with HMGA2 overexpression in chronic Philadelphia chromosome-negative myeloproliferative disease, regardless of the partner chromosome involved in the translocation. Such overexpression may contribute to the pathogenesis of the disease, which otherwise of itself shows a favorable and stable course.
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Affiliation(s)
- Stefania Aliano
- Laboratory of Cytogenetics, Department of Internal Medicine, University of Genoa, V.le Benedetto XV-6, 16132 Genoa, Italy
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