ABSTRACT
Objective To analyze the clinical features of acute leukemia(AL) with positive mixed lineage leukemia(MLL)fusion gene in children,and explore their treatment protocols,prognosis factors,and so on.Methods Clinical features,treatment protocols,and prognosis factors were studied retrospectively among 51 AL patients with MLL fusion gene.MLL fusion gene was detected by morphology immunology,cytogenetics,molecul arbiology and reverse transcrption polymerase chain reaction(RT-PCR).Results Fifty-one AL patients with MLL fusion gene positive,included 37 cases of acute lymphoblastic leukemia(ALL) and 14 cases of acute myelocytic leukemia(AML).Forty-two patients exhibited abnormal clonal chromosome 11.MLL fusion gene rearrangements and MLL fusion gene partial tandem duplication were found among 36 cases and 15 cases,respectively.Thirty-two cases who received regular chemotherapy were followed up.Twenty-four cases including 19 cases of ALL and 5 cases of AML had achieved complete remission(CR).Six cases including 5 cases of ALL and 1 cases of AML had achieved more than 2 years CR.Sixteen cases were alive update including 12 cases of ALL and 4 cases of AML.Ten cases of positive MLL fusion gene were turning negative.Up to now,6 cases relapsed and 6 cases were dead.Conclusions The incidence of AL children with positive MLL fusion gene is low.It has some features,such as,high replapse rate and poor prognosis.A few patients sensitive to chemotherapies can achieve CR.They live with constant negative MLL fusion gene.