Abstract: Objective To explore the clinical features and prognosis of acute myeloid leukemia (AML) with positive TLS/ERG gene in children. Methods The clinical data of TLS/ERG gene positive AML in 6 children admitted from June 2008 to December 2018 were retrospectively analyzed, and the prognosis data of 62 similar cases of children reported in domestic and foreign literature were summarized and analyzed. Results Six AML children with positive TLS/ERG gene was 1 . 3 % of the AML children from 0 to 18 years admitted in the same period. They were 4 boys and 2 girls with a median age of 9 . 1 years ( 4 . 0 - 14 . 0 years). One case was complicated with central nervous system (CNS) leukemia at the onset. In addition to expressed myeloid markers CD 117 , CD 13 , CD 33 , and CD 34 , immunophenotypic expression of CD 56 was found in 4 ( 66 . 7 %) children. There was no remission after induction chemotherapy in 3 children. Bone marrow recurrence occurred in 3 of 5 children receiving allogeneic hematopoietic stem cell transplantation, and the median recurrence time was 11 . 6 months ( 3 . 0 - 22 . 0 months) after transplantation. After transplantation, one patient relapsed in the form of CNS leukemia, but the bone marrow was in sustained remission. Bone marrow had the sustained remission in 1 case. By summarizing the prognostic data of children with TLS/ERG positive AML reported in the literature, it was found that all patients in the chemotherapy group experienced recurrence, and the recurrence rate in the transplantation group was 69 . 2 %. One of the patients had sustained remission and long-term survival after a second transplant following recurrence. Conclusions The incidence of TLS/ERG positive AML is extremely low, most of its immunophenotypes are associated with CD 56 expression, and the overall prognosis is poor. Hematopoietic stem cell transplantation can improve the prognosis, which is still the recommended treatment for the first remission period, but the recurrence rate after transplantation is still high. It is needed to improve treatment methods and find new treatment options.

Key words: acute myeloid leukemia; fusion gene; prognosis; child