FISH detection of PML-RARA fusion in ins(15;17) acute promyelocytic leukaemia depends on probe size (original) (raw)
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https://www.ijrrjournal.com/IJRR\_Vol.6\_Issue.3\_March2019/Abstract\_IJRR002.html, 2019
Background: Acute promyelocytic leukaemia (APML) is a sub-type of acute myeloid leukaemia (AML). APML accounts for 10% of all AML diagnosis. Diagnosis is made by presence of abnormal promyelocytes in circulating blood and bone marrow smear and presence of PML RARA fusion transcript which is responsible for leukemogenesis. Fluorescence in situ Hybridisation (FISH) plays key role in confirming diagnosis by detecting PML/RARA (15;17) translocation which will help in deciding treatment and prognosis in patients diagnosed with APML. Aims and objectives: To estimate presence of PML/RARA translocation in patients diagnosed with APML using FISH. Materials and methods: Bone marrow samples of 20 patients diagnosed with APML was collected for standardized lymphocyte culture method followed by standard protocol for FISH using commercially available probes for PML /RARA gene. Ethical clearance was obtained from institutional ethical committee. Results: Out of 20 patients, 18 patients had shown positive result for PML/RARA translocation. Hence 90% of patients showed positive results for fusion gene. Conclusion: Detection of PML/ RARA translocation helps in rapid diagnosis as well as treatment of patient with APML. Further it will also help in prognosis and follow up to detect residual disease in these patients.
Annals of Hematology, 2021
Dear Editor, Acute promyelocytic leukaemia (APL) is characterized by the presence of the t(15;17) chromosomal translocation that generates the PML-RARA fusion gene [1].PML-RARA, formed by the fusion of the promyelocytic leukaemia (PML) and retinoic acid receptor α (RARA) genes, is a constitutively active nuclear receptor that exerts transcriptional repression of RARα target genes leading to enhanced self-renewal capacity and myeloid differentiation block [2]. In approximately half of all cases, APL cells harbor additional mutations in genes such as FLT3, WT1, NRAS or KRAS [3, 4]. Mice expressing PML-RARA under the control of various promoters develop APL-like disease with variable penetrance and only after a significant period of latency (6–16 months) [5, 6]. These observations suggest a long latency between PML-RARA acquisition and APL onset, as reported for somatic mutations associated with acute myeloid leukaemia with a normal karyotype (AML-NK) [7]. Here, to investigate whether ...
British Journal of Haematology, 1995
This study reports the results of a simultaneous application of cytogenetic fluorescence in situ hybridization (FISH) and molecular analysis (RT-PCR) in 28 APL cases (23 M3 and five M3v; 26 studied at diagnosis and two at relapse). FISH on metaphases identified the t(15;17) in all cases who were positive for the PML/RAR a transcript by RT-PCR. Conventional cytogenetics revealed the t( 15; 17) in only 68% of cases. However, it enabled the detection of additional chromosome changes in five cases, three of whom were M3v. 11 patients were also investigated during complete remission (CR) by both FISH and RT-PCR, in order to evaluate residual disease; the duration of CR at the time of analysis ranged between 1 and 1 6 months, with three patients being studied twice. Comparison of RT-PCR and FISH results showed a very good correlation. In fact, of the 10 samples which were RT-PCR positive for residual disease, all were also recognized by interphase FISH, and eight were positive by metaphase FISH. Of the three samples negative at RT-PCR, all were also negative at the interphase FISH. The results of this study indicate that: (a) the t(15;17) is present in all cases positive for the PML/RAR Q rearrangement, thus in virtually all true APLs; (b) standard cytogenetics, capable of unravelling the t( 1 5; 17) in only 68% of cases, enables recognition of additional chromosome changes of potential clinical and prognostic significance; (c) FISH on interphase nuclei is a reliable tool for the monitoring of residual disease, with a sensitivity greater than that of FISH on metaphase cells and superimposable to that of RT-PCR.
Cancer Genetics and Cytogenetics, 1995
A 39-year-old woman was diagnosed with acute promyelocytic leukemia (APL) with disseminated intravascular coagulation syndrome. The hematologic examination showed a morphologic, cytochemical, and immunophenotypic picture typical of an APL, with a marked leukocytosis and o mixed population of hypergranular and microgranular promyelocytes. The cytogenetic analysis showed a 46,XX,t(9;22) karyotype, without any alterations of chromosomes 15 and 17. The t(15;17) translocation was not evident in FISH experiments, while a molecular analysis revealed the presence of a PML-RARa chimera.
Rapid diagnostic approach to PML-RARα-positive acute promyelocytic leukemia
The Hematology Journal, 2002
Introduction: Acute promyelocytic leukemia (APL) is a distinct entity characterized by a speci®c bone marrow morphology and a rearrangement of the PML-and the RARa-gene mostly due to a balanced translocation between the long arm of chromosome 15 with a breakpoint in 15q22 and the long arm of chromosome 17 with a breakpoint in 17q12-21. The introduction of all trans retinoic acid (ATRA) into treatment protocols has improved the outcome of APL dramatically. Therefore, it is essential to establish the diagnosis of APL as quickly and as reliably as possible. Materials and methods: We investigated 1714 newly diagnosed AML. In 92 cases an AML M3 (n=67) or M3v (n=25) was diagnosed using cytomorphology. In all these cases chromosome banding analysis and molecular studies were performed. Results: In 3/92 APL cases (3.2%) normal chromosomes 15 and 17 in chromosome banding analysis were observed. In these cases either an insertion of parts of the PML-gene into the RARalocus or an insertion of parts of the RARa-gene into the PML-locus was detected by FISH analysis. In all three patients a PML-RARa-rearrangement was also observed by RT ± PCR. Conclusion: A small subgroup of APL shows cryptic rearrangements of the PML-and RARa-gene that are undetectable by cytogenetics. This is analogous to Ph-negative, BCR-ABL-positive CML cases. FISH and RT ± PCR have to be performed in all cases that show the typical characteristics of AML M3 or M3v in cytomorphology in addition to chromosome banding analysis. The Hematology Journal t(15;17)-negative, PML-RARa-positive APL C Schoch et al 262 The Hematology Journal t(15;17)-negative, PML-RARa-positive APL C Schoch et al
British Journal of Haematology, 1992
Acute promyelocytic leukaemia (APL; AML M3) is identified by a unique t( 15;17) translocation which fuses the PML gene to the retinoic acid receptor alpha gene (RARA). Keverse transcription coupled with the polymerase chain reaction (RT-PCR) has been used to develop a diagnostic test for APL based on the PML-RARA fusion message. Separate PCR assays were designed to amplify either PML-RARA (1 5q + derived) or RARA-PML (1 7q-derived) chimaeric transcripts. PML-RARA transcripts were detected in every case from a series of 18 APL patients with cytogenetically confirmed t( 1 5; 1 7) translocations, whereas RARA-PML messages were detected in only 67% (12/18) of these
Leukemia, 2012
The PML-RARA fusion protein is found in approximately 97% of patients with acute promyelocytic leukemia (APL). APL can be associated with life-threatening bleeding complications when undiagnosed and not treated expeditiously. The PML-RARA fusion protein arrests maturation of myeloid cells at the promyelocytic stage, leading to the accumulation of neoplastic promyelocytes. Complete remission can be obtained by treatment with all-trans-retinoic acid (ATRA) in combination with chemotherapy. Diagnosis of APL is based on the detection of t(15;17) by karyotyping, fluorescence in situ hybridization or PCR. These techniques are laborious and demand specialized laboratories. We developed a fast (performed within 4-5 h) and sensitive (detection of at least 10% malignant cells in normal background) flow cytometric immunobead assay for the detection of PML-RARA fusion proteins in cell lysates using a bead-bound anti-RARA capture antibody and a phycoerythrin-conjugated anti-PML detection antibody. Testing of 163 newly diagnosed patients (including 46 APL cases) with the PML-RARA immunobead assay showed full concordance with the PML-RARA PCR results. As the applied antibodies recognize outer domains of the fusion protein, the assay appeared to work independently of the PML gene break point region. Importantly, the assay can be used in parallel with routine immunophenotyping for fast and easy diagnosis of APL.
Cancer Genetics and Cytogenetics, 2005
We describe a patient with acute promyelocytic leukemia (APL) and the karyotype 46,XX,i(17)(q10) with PML-RARA fusion gene detected by fluorescence in situ hybridization (FISH) and nested reverse transcriptase-polymerase chain reaction (RT-PCR). FISH using dual-color translocation probes for PML (promyelocytic leukemia) and RARA (retinoic acid receptor-alpha) showed fusion signal for PML-RARA on both arms of i(17q). The patient attained complete remission (CR) with all-trans retinoic acid treatment and became PML-RARA negative. One year later, while PML-RARA negative on FISH and RT-PCR, the patient presented with thrombocytopenia. Bone marrow examination suggested an acute monoblastic leukemia (AML-M5a) including the karyotype 46,XX,t(8;16) (p11.2;p13.3),inv(11)(p15q22~q23)[11]/47,idem,ϩi(8)(q10) . She is currently in CR. The occurrence of therapy related acute leukemia after successful therapy for APL is an emerging problem.