[Detection and clinical features of MLL gene rearrangement in adult patients with acute leukemia].

This study was purposed to investigate the incidence of mixed lineage leukemia (MLL) gene rearrangement and partner gene types as well as the clinical features and prognosis of acute leukemia (AL) with this rearrangement through detection in adult AL using combination of 3 techniques, and to evaluate the clinical value of this combination detection. The MLL gene rearrangement in 183 cases of adult AL was detected by combination of conventional cytogenetics, split signal FISH and multiplex nested PCR. The results showed that the incidence of MLL rearrangements in adult patients with AL was low (8.2%), and MLL-AF4 fusion gene was most common and predominant in acute lymphoblastic leukemia (ALL), while the MLL-AF6 and MLL-AF9 were most frequent in acute myeloid leukemia (AML). Extramedullary involvements were found in 40% of MLL-rearranged AL patients, and 33.3% of patients with MLL-rearranged AL reached to complete remission within 30 days during induction chemotherapy. In addition, in this cohort of MLL-rearranged adult AL patients, the 3-month relapse rate and 6-month overall survival rate were 50.0% and 50.0% respectively. It is concluded that the rate of missed diagnosis of CC technique for patients with MLL-rearranged AL reached to 60% in this study, while the combination of CC, FISH and multiplex nested PCR has been confirmed to have important significance for evaluating prognosis and conducting clinical therapy of patients with MLL-rearranged AL.