OBJECTIVETo report an acute promyelocytic leukaemia (APL) case with translocation of rob (13;21) t(15;17) (q22;q21) and review its clinical and laboratory characteristics.

METHODSBased on routine karyotype analysis and bone marrow morphology, we further used double color double fluorescent in situ hybridization (DCDF-FISH) and reverse transcriptase PCR (RT-PCR) to examine the patient's abnormities on cytogenetic and molecular biology, and reveal the clinical characteristics of this rare translocation also from the related literatures.

RESULTSThe clinical manifestation and bone marrow morphology examination of this patient were in accordance with pathologic feature of APL. On first visit, immunophenotyping analysis showed positive myeloid markers. Through R-banding, the patient's karyotype was confirmed as 45, XX, rob(13;21) t(15;17) (q22;q21) [6]/45, XX, rob(13;21) [14]. FISH results showed that 68.9% cells were typical t(15;17) pattern. The positive rates of fusion gene of PML-RARα detected by RT-PCR was 25.8%. Patient was treated by induction and consolidation therapy, the karyotype was 45, XX, rob(13;21 )[20] after complete remission. The positive rate of fusion gene of PML-RARα by FISH and its level were 2.5% and 0.003% respectively.

CONCLUSIONAPL with rob (13;21) t(15;17) (q22;q21) was very rare, which was accorded with clinical and laboratory characteristics of APL. The value of chromosome abnormality as a prognostic marker in APL needs to be further observed..

Chromosome Aberrations ; Chromosome Banding ; Chromosomes, Human, Pair 15 ; Chromosomes, Human, Pair 17 ; Chromosomes, Human, X ; Humans ; In Situ Hybridization, Fluorescence ; Karyotype ; Leukemia, Promyelocytic, Acute ; Oncogene Proteins, Fusion ; Remission Induction ; Translocation, Genetic