Objective: To explore the value of reverse transcription-multiplex nested PCR in detecting MLL rearrangement in lzAML-M4/M5.
Methods: Bone marrow chromosome preparation was made using direct method or short-term culture. Karyotypic analysis was carried out by R-banding technique. Five common MLL fusion genes and MLL partial tandem duplication in 40 AML cases, including 12 M4 and 28 M5 were detected by reverse transcription(RT)-multiplex nested PCR.
Results: R-banding karyotypic analysis revealed 11q23 translocation including t(6;11)(q27;q23), t(9;11)(p21;q23), t(11;17)(q23;q21) and t(11;19)(q23;p13.1) in 7 cases. MLL rearrangements consisting of MLL/AF6 (1 case), MLL/AF9 (1 case), MLL/AF17 (2 cases), MLL/ELL (2 cases) and MLL partial tandem duplication(2 cases) were detected in 8 cases by RT-multiplex nested PCR. Among 8 cases with MLL rearrangement, 6 were chromosome translocation, 2 were MLL partial tandem duplication.
Conclusion: RT-multiplex nested PCR is a powerful technique in the detection of MLL rearrangement for tentativelly diagnosed AML-M4/M5.