A new variant t(6;15;17)(q25;q22;q21) in acute promyelocytic leukemia: fluorescence in situ hybridization confirmation.
ABSTRACT Acute promyelocytic leukemia (APL) is characterized by the t(15;17)(q22;q21), which results in the fusion of the promyelocytic leukemia (PML) gene at 15q22 with the retinoic acid alpha-receptor (RARalpha) at 17q21. The 2 chimeric genes PML/RARalpha and RARalpha/PML are thought to play a role in leukemogenesis. We report a case of APL in a patient carrying an apparently complex variant translocation identified as t(6;15;17) by R-banding and whole chromosome 15 and 17 painting. However, FISH analysis with a PML/RARalpha dual-color kit showed a more complex translocation, resulting presumably from a two-step rearrangement, with PML-RARalpha fusion gene located as expected on the der(15) but the residual 5'-RARalpha signal located on the der(6). The patient achieved complete remission with all-trans retinoic acid treatment associated with chemotherapy. This case illustrates the usefulness of combined cytogenetics, FISH, and molecular biology to evidence the PML/RARalpha fusion gene in complex cases.
- Leukemia & lymphoma 04/2009; 50(3):466-70. · 2.61 Impact Factor
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ABSTRACT: Nowadays the role of genetic findings in determining the diagnosis, therapy and prognosis of acute myeloid leukemia (AML) has become more valuable. To improve and validate the detection of clonal chromosomal aberrations in leukemia, we designed a combined application of karyotyping with multiplex reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH), and addressed the expression and distribution of fusion genes among the subtypes of Chinese adult patients with de novo AML. Multiplex RT-PCR assays were performed on 477 samples from newly diagnosed AML patients, and cytogenetic data were obtained from 373 of them by R or G banding techniques and those in some cases were confirmed by FISH. The PCR products in some suspected cases were tested by two-directional sequencing. The results showed that except unqualified samples, fusion genes were detected by multiplex RT-PCR in 211 of 474 patients (44.51%), including AML1-ETO, CBFβ-MYH11, PML-RARα, PLZF-RARα, NPM-RARα, MLL rearrangements, BCR-ABL, DEK-CAN, SET-CAN, TEL-PDGFR, TLS-ERG, AML1-MDS1 (EVI-1). In 373 patients, who took both multiplex RT-PCR and karyotype analysis, the detection rate of chromosomal aberrations by using multiplex RT-PCR and karyotyping was 160/373 (42.89%) and 179/373 (47.98%) respectively, and the combination could optimize the detection rate of clonal genetic abnormalities to 216/373 (57.90%). The PCR results from 11 cases "normal" in karyotyping but abnormal in RT-PCR for MLL rearrangements were confirmed by two-directional sequencing. It is concluded that karyotype studies remain the cornerstone for genetic testing; conventional cytogenetics and molecular-based methods are complementary tests for the detection of clonal genetic aberrations in AML, especially for the cryptic or submicroscopic aberrations. Once a genetic marker has been identified by combined analysis, it could be used to monitor residual disease during/after chemotherapy, by quantitative RT-PCR and/or FISH.Journal of Huazhong University of Science and Technology 08/2012; 32(4):501-10. · 0.78 Impact Factor
- The Korean journal of hematology 01/2007; 42(4).