Studies On Detection Of Rearrangements Of MLL Gene In Acute Monocytic Leukemia

Objective: To explore the value of fluoresence in situ hybridization (FISH) technique and reverse transcriptase-multiplex nested polymerase chain reaction technique in the detection of mixed lineage leukemia(MLL) gene rearrangement in acute monocytic leukemia; To report a novel and unrecorded translocation (3;20)(q13;p13) in a patient with incurable and relapsing acute monocytic leukemia(AML-M5).Methods: Dual-color MLL probe was used to detect the MLL rearrangement in 26 cases AML-M5. Setting 3 parallel systems of PCR, common MLL gene rearrangements in 26 cases AML-M5 were detected by RT-Multiplex Nested PCR technique. The results were compared with conventional cytogenetics. Chromosome painting with whole chromosome painting probes for chromosomes 3 and 20 were performed in 1 patient with incurable and relapsing AML-M5.Results: MLL rearrangements were deteced in 9/26 AML-M5 by FISH, and 10/26 by RT-Multiplex Nested PCR. A reciprocal translocation between 3 and 20 was further confirmed by chromosome painting technique in 1 patient with incurable and relapsing AML-M5.Conclusion:â‘ Interphase FISH was more sensitive method for the detection of MLL rearrangement than convertional cytogenetic method.â‘¡RT-Multiplex Nested PCR confirmed translocation detected by convertional cytogenetic method, but also detected MLL partial tandem duplication that could not been detected by cytogenetic examination or FISH.â‘¢In order to raise the detecting rate of MLL rearrangement, it is necessary to use FISH and/or RT-Multiplex Nested PCR to screen all the patients with acute leukemia.â‘£A novel and unrecorded translocation (3;20)(q13;p13) was reported in a patient with incurable and relapsing acute monocytic leukemia(AML-M5).