Cytogenetic and molecular genetic methods for chromosomal translocations detection with reference to the KMT2A/MLL gene

2020 ◽  
pp. 1-27
Author(s):  
Nikolai Lomov ◽  
Elena Zerkalenkova ◽  
Svetlana Lebedeva ◽  
Vladimir Viushkov ◽  
Mikhail A. Rubtsov
Keyword(s):  
Molecular Genetic ◽  
Chromosomal Translocations ◽  
Mll Gene

Analyzing the MLL Recombinome.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4267-4267
Author(s):  
Claus Meyer ◽  
Bjoern Schneider ◽  
Martin Reichel ◽  
Sieglinde Angermuller ◽  
Susanne Schnittger ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Chromosomal Translocations ◽  
Clinical Decisions ◽  
Disease Entity ◽  
Acute Leukemias ◽  
Novel Technique ◽  
Mll Gene ◽  
Distinct Disease ◽  
Distinct Disease Entity

Abstract Acute leukemias are frequently associated with specific chromosomal translocations of the human MLL gene. In general, MLL translocations define a distinct disease entity that needs to be diagnosed with precision to facilitate rapid clinical decisions. Here we present data about a new PCR based method that uses patient genomic DNA to identify any MLL fusion. Fourty different MLL translocations were successfully analyzed. We will present three novel MLL translocation partner genes and a new MLL deletion. The benefits of this novel technique for diagnosis and MRD analyses will be discussed. Supported by grant 2001.061.1 from the Wilhelm Sander foundation.

Molecular Genetic Characterization of 3'-Deletion of MLL Gene in Infant Acute Leukemia.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2498-2498
Author(s):  
Grigory Tsaur ◽  
Olga Plekhanova ◽  
Alexander Popov ◽  
Tatyana Gindina ◽  
Yulia Olshanskaya ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Leukemia ◽  
Lymphoblastic Leukemia ◽  
Molecular Genetic ◽  
Fish Analysis ◽  
Long Distance ◽  
Mll Gene ◽  
Partner Gene ◽  
Genetic Features ◽  
Blast Cells

Abstract Abstract 2498 Background. MLL gene rearrangements are associated with unfavorable outcome in infant acute lymphoblastic leukemia (ALL) and have intermediate prognosis in infant acute myeloid leukemia (AML). Application of fluorescence in-situ hybridization (FISH) allows detecting not only conventional MLL rearrangements, but also concurrent 3'-deletion of MLL gene. However, detailed characteristics of infant leukemia carrying 3' MLL deletion remain unclear. Aim. To investigate molecular genetic features of MLL-rearranged infant acute leukemia with concurrent 3' MLL deletion. Methods. 64 patients (27 boys and 37 girls) aged from 1 day to 11 months (median 6.6 months) including 44 ALL patients, 18 AML patients, 1 patient with acute bilineage leukemia and 1 patient with acute undifferentiated leukemia were enrolled in the current study. Chromosome banding analysis was done according to standard procedure. FISH analysis using LSI MLL Dual Color, Break Apart Rearrangement Probe (Abbott Molecular, USA) was performed on at least 200 interphase nuclei and on all available metaphases. Presence of MLL rearrangements was detected by FISH, reverse-transcriptase PCR. In 29 cases long-distance inverse PCR was additionally performed. In case of MLL rearrangement presence standard FISH pattern was defined as simultaneous detection of 3 different fluorescent signals: 1 fused (orange) signal, 1 green signal derived from 3' part of MLL gene, 1 red signal from 5' end of MLL (1F1G1R). MLL rearrangements with concurrent 3' MLL deletion led to 1F1R FISH pattern formation due to lack of green signal. Results. FISH revealed MLL rearrangements in 73% of ALL cases that was higher than frequency of 11q23 translocations detected by conventional cytogenetics — 55%. In MLL-positive cases we found 38 patients (81%) with standard FISH pattern, 7 ones (15%) with concurrent 3'-deletion of MLL gene and 2 (4%) with complex MLL rearrangements. Among patients with 3' MLL deletions there were 1 case with 5' MLL duplication (1F2R) and 1 case with 5' MLL triplication (1F3R). Frequency of 3'-deletions were similar in ALL and AML patients (13% and 15%, respectively). We did not find more than one FISH pattern in bone marrow blast cells of each patient with 3' MLL deletion. In this cohort of patients all blast cells carried concurrent 3'-deletion of MLL gene. Moreover, percentage of blast cells carrying MLL rearrangements did not differ significantly between patients with standard FISH pattern (median 97%, range 22–100%) and 3'-deletion (median 83%, range 13–99%) (p=0.206). 3'-deletion of MLL was not associated with breakpoint position in MLL gene and type of translocation partner gene. MLL translocation partner genes detected in patients with 3' deletions were as follows AF4(n=2), MLLT3(n= 3), MLLT10(n=2). None of the patients with 3'-deletions had reciprocal fusion gene. Initial patients' characteristics (age, sex, WBC count, immunophenotype, CNS-status, type of MLL partner gene) and treatment response parameters (day 8 peripheral blood blast cell count, day 15 bone marrow status, day 36 remission achievement, minimal residual disease status at time point 4) did not differ significantly between 2 groups. Although cumulative incidence of relapse was lower in patients with 3'-deletion as compared to patients with standard FISH pattern (0.31±0.04 and 0.55±0.01, respectively), difference between these two groups was not statistically significant (p=0.359). Conclusion. In our work we characterized rare subgroup of infant MLL-rearranged acute leukemia carrying concurrent 3' MLL deletion. Our data provide additional information of molecular genetic features of acute leukemia in children younger than one year. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The Role of Molecular Genetic Translocations in the Initial Response to the Treatment under the ALLIC BFM 2009 Program in Children Patients with Acute Lymphoblastic Leukemia

2021 ◽  
Vol 6 (3) ◽  
pp. 162-169
Author(s):  
O. A. Vynnytska ◽  
◽  
O. I. Dorosh ◽  
L. Ya. Dubey ◽  
N. V. Dubey
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Correlation Analysis ◽  
Peripheral Blood ◽  
Lymphoblastic Leukemia ◽  
Molecular Genetic ◽  
Primary Response ◽  
Chromosomal Translocations ◽  
Induction Treatment ◽  
Blast Cells

The correlation analysis between the number of blast cells in bone marrow and peripheral blood was performed, and the dependence of blast percentage on the presence of molecular genetic translocations (AF4/MLL, BCR/ABL1, TEL/AML, E2A/PBX1) in patients with acute lymphoblastic leukemia (ALL) under the conditions of ALLIC-BFM 2009 cytostatic therapy was researched. The purpose of the study was to establish a relationship between the number of blast cells in bone marrow and peripheral blood depending on the presence of molecular genetic translocations for early detection of induction treatment by ALLIC BFM 2009. Materials and methods. The survey group consisted of 105 children aged 12 months to 16 years (median age was 6 years). Among those surveyed were 62 boys (59.0%) and 43 girls (41.0%). All patients were diagnosed with acute lymphoblastic leukemia. Results and discussion. Correlation analysis revealed a high degree of correlation between the number of blast cells in the bone marrow and peripheral blood, as the correlation coefficient (r) is 0.87. It is shown that the increase in the number of blast cells depends on the presence of chromosomal translocations. The highest number of blasts was observed in patients with BCR/ABL1 and E2A/PBX1 translocations, in whom the content of blasts in bone marrow was 97 and 96%, respectively, and in peripheral blood - 67 and 73%, respectively. It was found that treatment under the ALLIC BFM 2009 program leads to a decrease in the number of blast cells in the bone marrow and blood with minimal values on the 33rd day of treatment. It has been shown that the highest levels of blast cells during chemotherapy are observed in patients with chromosomal translocations BCR/ABL1 and E2A/PBX1. In patients with AF4/MLL translocation, the efficacy of therapy was the highest because no blast cells in the bone marrow were visualized on day 33 of treatment. The study of the primary response of patients with acute lymphoblastic leukemia to induction treatment according to the ALLIC BFM 2009 program revealed the dependence of the level of blast cells of bone marrow and blood on the type of chromosomal aberration. Patients with BCR/ABL1 and E2A/PBX1 have the highest resistance to chemotherapy with molecular genetic translocations, and patients with AF4/MLL and TEL/AML have the lowest resistance, as evidenced by the presence and absence of blast cells in the peripheral blood, respectively. Conclusion. Establishing the relationship between cytogenetic and molecular genetic features of the tumour clone will help determine the degree of malignancy of the process, as well as the risk group for the course of the disease. Determining the dependence of acute leukemia on molecular genetic translocations will make it possible to further modify the treatment program

Overview of the Role of Molecular Methods in the Diagnosis of Malignant Lymphomas

1999 ◽  
Vol 123 (12) ◽  
pp. 1189-1207 ◽  
Author(s):  
L. Jeffrey Medeiros ◽  
Jeanne Carr
Keyword(s):  
Polymerase Chain Reaction ◽  
Molecular Genetics ◽  
Tumor Suppressor Genes ◽  
Southern Blot Analysis ◽  
Molecular Genetic ◽  
Chromosomal Translocations ◽  
Chain Reaction ◽  
Malignant Lymphomas ◽  
Polymerase Chain

Abstract Objective.—To review the role of molecular genetics in the diagnosis of malignant lymphomas. Data Sources and Study Selection.—Primary research studies and reviews published in the English literature that focus on molecular genetics and malignant lymphoma, in particular, clonality, chromosomal translocations, tumor suppressor genes, and Hodgkin disease. Data Extraction and Synthesis.—Molecular genetics has an important role in the assessment of malignant lymphomas. Clonality, detected by Southern blot analysis or the polymerase chain reaction, is helpful for establishing the diagnosis of lymphoma in lesions with ambiguous morphologic and immunophenotypic findings. Southern blot analysis is the “gold standard” for clonality assessment, but the process is labor-intensive and time-consuming. Polymerase chain reaction analysis is more convenient, but a potentially significant false-negative rate exists in the analysis of some antigen receptor genes as a result of using consensus primers and the process of somatic hypermutation. Chromosomal translocations, which result in oncogene activation, occur in many types of B- and T-cell lymphomas, and their detection is helpful in classification as well as in establishing a diagnosis of malignancy. Gene rearrangements and chromosomal translocations also can be used to monitor minimal residual disease. Tumor suppressor genes, although their analysis is relatively less useful for diagnosis, are involved in both pathogenesis and tumor progression and will be more important diagnostically as this field continues to expand. Molecular genetic analysis has played a major role in improving our understanding of Hodgkin disease. Conclusions.—Molecular genetic tests are currently important ancillary tools for the diagnosis and classification of malignant lymphomas, and their role is likely to increase in the future.

Rearrangement of the MLL Gene in Acute Lymphoblastic and Acute Myeloid Leukemias with 11q23 Chromosomal Translocations

1993 ◽  
Vol 329 (13) ◽  
pp. 909-914 ◽  
Author(s):  
Michael J. Thirman ◽  
Heidi J. Gill ◽  
Robert C. Burnett ◽  
David Mbangkollo ◽  
Norah R. McCabe ◽  
...  
Keyword(s):  
Chromosomal Translocations ◽  
Mll Gene ◽  
Myeloid Leukemias ◽  
Acute Myeloid

scholarly journals Inflammatory myofibroblastic tumours: where are we now?

2007 ◽  
Vol 61 (4) ◽  
pp. 428-437 ◽  
Author(s):  
B C Gleason ◽  
J L Hornick
Keyword(s):  
Soft Tissues ◽  
Spindle Cell ◽  
Molecular Genetic ◽  
Young Patients ◽  
Chromosomal Translocations ◽  
Inflammatory Pseudotumour ◽  
Molecular Features ◽  
Generic Term ◽  
Spindle Cell Proliferation ◽  
Genetic Features

Inflammatory pseudotumour is a generic term applied to a variety of neoplastic and non-neoplastic entities that share a common histological appearance, namely a cytologically bland spindle cell proliferation with a prominent, usually chronic inflammatory infiltrate. Over the last two decades, inflammatory myofibroblastic tumour (IMT) has emerged from within the broad category of inflammatory pseudotumour, with distinctive clinical, pathological and molecular features. IMT shows a predilection for the visceral soft tissues of children and adolescents and has a tendency for local recurrence, but only a small risk of distant metastasis. Characteristic histological patterns include the fasciitis-like, compact spindle cell and hypocellular fibrous patterns, which are often seen in combination within the same tumour. Chromosomal translocations leading to activation of the ALK tyrosine kinase can be detected in approximately 50% of IMTs, particularly those arising in young patients. This review will examine the clinical, pathological, and molecular genetic features of IMT and discuss an approach to diagnosis and differential diagnosis.

Leukemia- and lymphoma-associated flow cytometric, cytogenetic, and molecular genetic aberrations in healthy individuals

2012 ◽  
Vol 153 (14) ◽  
pp. 531-540
Author(s):  
János Jakó ◽  
László Szerafin
Keyword(s):  
B Cell ◽  
Fusion Gene ◽  
Molecular Genetic ◽  
Jak2 V617f ◽  
Chromosomal Translocations ◽  
Jak2 V617f Mutation ◽  
Healthy Individuals ◽  
Specific Flow ◽  
Genetic Aberrations ◽  
Flow Cytometric

Most leukemia and lymphoma cases are characterized by specific flow cytometric, cytogenetic and molecular genetic aberrations, which can also be detected in healthy individuals in some cases. The authors review the literature concerning monoclonal B-cell lymphocytosis, and the occurrence of chromosomal translocations t(14;18) and t(11;14), NPM-ALK fusion gene, JAK2 V617F mutation, BCR-ABL1 fusion gene, ETV6-RUNX1(TEL-AML1), MLL-AF4 and PML-RARA fusion gene in healthy individuals. At present, we do not know the importance of these aberrations. From the authors review it is evident that this phenomenon has both theoretical and practical (diagnostic, prognostic, and therapeutic) significance. Orv. Hetil., 2012, 153, 531–540.

AF4-MLL Expression Is Necessary and Sufficient for Leukemia Onset in Mice

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 685-685
Author(s):  
Adelheid Bursen ◽  
Karen Schwabe ◽  
Brigitte Rüster ◽  
Anne Wenger ◽  
Martin Ruthardt ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Lymphoblastic Leukemia ◽  
Model System ◽  
Chromosomal Translocations ◽  
Leukemic Cells ◽  
Human Leukemia ◽  
Fusion Genes ◽  
Chromosome 11 ◽  
Mll Gene ◽  
Necessary And Sufficient

Abstract Uniform structural and numerical chromosomal abnormalities are frequently demonstrated in human leukemia and lymphomas, probably as initiating events in cancer formation. Recurrent chromosomal translocations generally result in two derivative chromosomes, both of which are usually present in the leukemic blasts at the time of diagnosis. The human MLL (mixed lineage leukemia) gene on chromosome 11, band q23, participates in a variety of chromosomal translocations, which are assumed to be the initial step of the malignant transformation of haematopoietic cells leading to malignancies of myeloid and/or lymphoid lineage. Translocation t(4;11)(q21;q23) fuses the MLL gene to the AF4 (ALL-1 fused gene on chromosome 4; MLLT2) gene and is one of the most frequent rearrangements of the human MLL gene, being particularly common in infant acute lymphoblastic leukemia (ALL) associated with a poor outcome with treatment. Of note, the fusion of MLL to most other partners results in acute myeloid leukemia (AML). While MLL fusions associated with AML have been successfully established in mice, modeling a t(4;11) associated ALL emerged as more delicate. To generate such a model system in mice and to elucidate a potential association of the resulting fusion genes, MLL-AF4 and AF4-MLL for leukemia phenotype specification, the cDNA constructs of both fusion genes were used in a retroviral transduction/transplantation setup. Therefore murine HSCs (Lin−, Sca-1+) were transduced with either both fusion genes, or with MLL-AF4 or AF4-MLL alone, and subsequently administered by suborbital injection to sublethally irradiated recipient mice. Mice were observed daily and moribund primary AF4-MLL and MLL-AF4/AF4-MLL recipient mice were monitored after a latency of approximately 6 months and with a penetrance of 25% for the AF4-MLL and 40% for the MLL-AF4/AF4-MLL cohort. Diseased mice exhibited the following criteria for classification as a leukemic disorder: All leukemia mice showed enlarged spleen and thymus, and a massive infiltration of lymphoblast-like leukemic cells in the peripheral blood, bone marrow, and other major organs. cDNA cassettes of the fusion genes were transcribed in the analyzed samples, as assessed by RT-PCR. Furthermore, leukemic cells of AF4-MLL and MLL-AF4/AF4-MLL mice could be successfully re-transplanted into secondary recipients with a latency of 3–7 weeks and a penetrance of 90%, phenocopying the primary leukemia. Flow cytometry was used to further characterize the leukemic immunophenotype. Primary AF4-MLL recipients exclusively developed a CD3+ precursor T-cell lymphoblastic leukemia (Pre-T LBL; according to Bethesda proposals for classification of lymphoid neoplasms in mice), and aside from CD3+ Pre-T LBL, one of the MLL-AF4/AF4-MLL leukemia mice displayed a mixed lymphoid/myeloid malignancy. In contrast, expression of the MLL-AF4 fusion protein in muHSCs did not show any detectable effect in recipient mice over an observation period of more than 13 months. Taken together, in this particular model system the expression of the AF4-MLL fusion protein in multi-potent haematopoietic stem cells is necessary and sufficient to cause cancer. Additional expression of the MLL-AF4 fusion protein in murine HSCs indicates an instructive function in lineage determination of the tumor. For further examination of this finding we consider the establishment of a xenograft NOD/SCID mouse model expressing the fusion genes MLL-AF4 and AF4-MLL in human CD34+ cells.

Cytogenetic and Molecular Genetic Characterization Of MLL-PTD Positive AML In Comparison To MLL-Translocated AML

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2557-2557 ◽  
Author(s):  
Claudia Haferlach ◽  
Alexander Kohlmann ◽  
Wolfgang Kern ◽  
Torsten Haferlach ◽  
Susanne Schnittger
Keyword(s):  
De Novo ◽  
Molecular Genetic ◽  
Genetic Alterations ◽  
The Other ◽  
Employment Equity ◽  
Cytogenetic Abnormalities ◽  
Mll Gene ◽  
Equity Ownership ◽  
De Novo Aml ◽  
Tandem Duplications

Background Partial tandem duplications within the MLL gene (MLL-PTD) are a recurrent molecular alteration in acute myeloid leukemia (AML). MLL-PTD occurs with a frequency of 6-8% in de novo AML. Data on additional cytogenetic and molecular alterations in MLL-PTD+ AML is scarce. Beside partial tandem duplications within the MLL gene, the MLL gene is also a target of balanced translocations leading to the fusion of MLL with a large variety of partner genes. Aims 1. Evaluate the spectrum of additional cytogenetic and molecular genetic alterations. 2. Analyze whether additional aberrations impact prognosis. 3. Compare the spectrum of additional abnormalities between MLL-PTD+ AML and AML with MLL-translocations. Patients and Methods We selected a cohort of 225 de novo AML patients harboring a MLL-PTD. These were compared to a cohort of 130 de novo AML with MLL-translocation (MLL-t). Mutation screening for the following genes was performed in pts with MLL-PTD and MLL-t, respectively: ASXL1 (132; 85), CEBPA (184; 67), FLT3-ITD (225; 125), FLT3-TKD (208; 112), IDH1R132 (145; 88), IDH2R140 (141; 63), IDH2R172 (137; 73), KRAS (59; 82), NRAS (98; 82), RUNX1 (213; 97), NPM1 (221; 123), TP53 (104; 89), and WT1 (159; 86). EVI1 expression was assessed in 55 MLL-PTD+ pts and in 77 pts with MLL-t. Results The frequency of MLL-PTD and MLL-translocations differed significantly with respect to age. While MLL-PTD were more frequent in elderly pts, MLL-t were more frequent in younger pts (<10 yrs: 0%/2.3%; 10-19 yrs: 0%/3.8%, 20-29 yrs: 0.9%/13.1%, 30-39 yrs: 3.1%/9.2%, 40-49 yrs: 8.9%/23.1%; 50-59 yrs: 11.1%/13.1%; 60-69 yrs: 35.1%/13.8%; 70-79 yrs: 29.3%/13.8%; ≥80 yrs: 11.6%/7.7%; p<0.001). FAB subtype distribution differed significantly between of MLL-PTD+ and MLL-t AML. While in MLL-PTD+ AML most frequently subtypes M1 (33.8%) and M2 (43.6%) were observed, AML with MLL-t most frequently showed M4 (30%) and M5a (23.1%). The most frequent cytogenetic abnormalities in MLL-PTD+ cases were gains of 11q (n=37), followed by 8q (n=14), and 13q (n=7) and losses of 5q (n=14), 7q (n=14) and 17p (n=5). In contrast, in MLL-t patients the most frequent gains were trisomies 6 (n=7) and 8 (n=33), as well as gains of 1q (n=10), 19p (n=10), 19q (n=8) and 21q (n=21). There were many significant differences in co-occurring mutations between MLL-PTD+ and MLL-t: DNMT3Amut: 44.7% vs 0% (p<0.001), FLT3-ITD: 33.3% vs 3.2% (p<0.001), IDH1R132 14.5% vs 0% (p<0.001), IDH2R140: 19.9% vs 0% (p<0.001), IDH2R172 9.5% vs 0% (p=0.005), and RUNX1 25.8% vs 2.1% (p<0.001). On the other hand KRASmut (3.4% vs 23.2%, p=0.001) and NRASmut (8.2% vs 25.6%, p=0.002) were less frequent in MLL-PTD+ as compared to MLL-t AML. TP53 mutations were observed in comparable frequencies (3.8% vs 5.6%). NPM1 mutations were not detected in either entity. The mean EVI1 expression was significantly higher in MLL-t pts compared to MLL-PTD+ pts (167.1+/-259.1vs 0.4 +/- 0.47, p<0.001). Overall, chromosome abnormalities in addition to the MLL alteration were more frequent in MLL-t AML as compared to MLL-PTD+ AML (mean number of alterations: 1.2 vs 0.7, p=0.004). This goes along with more additional molecular mutations in MLL-PTD+ AML as compared to MLL-t AML (mean number of molecular mutations: 1.5 vs 0.6, p=0.004). Overall survival at 5 yrs was comparable in both subgroups (MLL-PTD+: 27.9% vs MLL-t: 39.8%). In both subgroups age was significantly associated with OS (<60 yrs vs ≥60 yrs: MLL-PTD+: 56.9 vs 16.3 months, MLL-t: 47.8 vs 9.7 months, for both p<0.001). Neither in MLL-PTD+ AML nor in MLL-t AML the presence of additional chromosome aberration had an impact on outcome. With respect to molecular mutations only IDH2R140 was significantly associated with shorter OS (HR: 2.2, p=0.007) and IDH2R172 with longer OS (HR: 0.2, p=0.04) in MLL-PTD+ AML. Conclusions Although both MLL-PTD+ and MLL-translocations disrupt the same gene AML harboring one or the other MLL abnormality differ significantly with respect to age distribution, the pattern of additional cytogenetic abnormalities and the frequency of accompanying molecular mutations. MLL-PTD is more frequent in older patients, presents most frequently as FAB M1 and M2, and harbors more additional molecular genetic events and less additional cytogenetic events. However, both AML subtypes are associated with adverse outcome, particularly in elderly patients. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Sign in / Sign up

Export Citation Format

Share Document