One case of acute promyelocytic leukemia with 3'RARα submicroscopic deletion / 白血病·淋巴瘤

ABSTRACT

Objective To report a rare case of M3r subtype of acute promyelocytic leukemia (APL)with 3'-end of RARα (3'RARα) submicroscopic deletion, and the characters of morphologic, cytogenetic,molecular genetic and molecular biology studies. Methods Chromosomes of bone marrow (BM) cells were prepared with direct method and short-term culture method, and R-banding technique was used for karyotypic analysis. Fluorescence in situ hybridization (FISH) assays were performed on fixed BM cells using the following specific DNA probes CEP X/Y alpha satellite DNA probe, LSI PML-RARα dual-color dual-fusion and LSI RARα dual-color break apart probes. A quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) was performed to detect the PML-RARα transcript. A multiplex nested RT-PCR was also performed, which may simultaneously detect the fusion genes derived from 29 chromosomal aberrations in acute leukemia including PML-RARα, PLZF-RARα and NPM-RARα fusion transcripts. Results R-banding analysis revealed a karyotype of 45,X,-Y[6]/46,XY[8], FISH using CEP X/Y probe further confirmed Y-chromosome loss. FISH analysis with RARα dual-color break apart probe demonstrated a deletion of the entire 3'-end of one allele of RARα gene. Cytogenetic, FISH and RT-PCR analyses showed no PML-RARα,PLZF-RARα, NPM-RARα, NuMA-RARα and STAT5b-RARα rearrangements. Conclusion A new RARαrearrangement involving 3'RARα submicroscopic deletion in APL without X-RARα fusion has been identified.FISH analysis with RARα dual-color break apart probe is a useful method for characterization of this abnormality, but its molecular consequences remain to be elucidated.