Objective To study the frequency of mixed-lineage leukemia(MEL)gene rearrangement and frequent types of fusion genes and the clinical characteristics in acute leukemia(AL)with MLL gene rearrangement.Methods MLL gene rearrangement was detected by multiplex nested RT-PCR in 109 cases of AL.Immunophenotypes were screened by flow cytometry and the chnical features of MLL gene rearranged were analyzed.Results MLL gene rearrangement were identified in 6.4%(7/109)of the patients,4 cases of AML,1 case of M2,1 case of M4,2 cases of M5,3 cases of.B-ALL.MLL-AF4,MLL-AF6,MLL-AF9,MLL-AF10.MLL-ENL were deleted by multiplex nested RT-PCR.Patients with MLL gene rearrangement presented higher initial white blood cell count(WBC)(P=0.019).Conclusion Multiplex nested RT-PCR is a fast and effective method to detect gene rearrangement of MLL in AL Patients with MLL gene rearrangement presented higher WBC and poor prognosis.

Objective To explore the frequencies of MPL exon 10 mutations in JAK2 V617F-negative myeloproliferative neoplasms patients. Methods MPLW515K/L was processed through allele-specific PGR combined with direct sequence analysis. The mutations of others MPL exon 10 were detected by single strand conformation polymorphism PGR (PCR-SSCP) combined with direct sequencing. Results Of the 103 patients with JAK2 V617F-negtive myeloproliferative neoplasms patients, 1 carried MPLW515K mutation (TGG→AAG)in PMF; 1 was found to have new mutation (CTGGTGATCGCT insert) in ET and have homozygous mutation. Conclusion JAK2 V617F-negtive myeloproliferative neoplasms patients carried additional mutations in addition to W515K/L mutations in MPL exon 10, but its frequency of mutation is low.