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.

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.