Simultaneous presence of ins (15;17),t(2;17;20) and trisomy 8 in a patient with acute promyelocytic leukemia / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To report a rare complex karyotypic abnormalities including ins (15;17),t(2;17;20) and trisomy 8 in a patient with acute promyelocytic leukemia (APL).</p><p><b>METHODS</b>Chromosomes were prepared after 24 h culture of bone marrow cells. R-banding technique was used to analyze the karyotype. Multiplex fluorescence in situ hybridization (M-FISH), chromosome painting using whole chromosome parint (WCP) 2, 15, 17 and 20 and interphase-FISH (I-FISH) using PML-RARa dual-colour dual-fusion translocation probe were performed to ascertain the essence and origin of the abnormal chromosomes detected by conventional karyotypic analysis.</p><p><b>RESULTS</b>Karyotypic analysis revealed a karyotype of 47, XY, 2q-, + 8, 17q+ , 20p+ . M-FISH analysis showed a karyotype of 47, XY, t(2;17;20) (q24;q21;p13), + 8, which was confirmed by chromosome painting. PML-RARa fusion gene which lied in the derivative chromosome 15 was detected by I-FISH suggesting a cryptic insertion (15;17)(q22;q21.1q21.3).</p><p><b>CONCLUSION</b>FISH is a reliable method for characterization of cryptic ins (15;17) and other complex translocations. It should be used in all suspected APL patients lacking t(15;17) by conventional karyotypic analysis.</p>