Abstract: Objective To analyze the clinical and laboratory characteristics of Leukemia with t（11;19）（q23;p13）. Methods Twenty-one patients with （11;19）（q23;p13） were reviewed including the data of conventional cytogenetic analysis,fluorescence in situ hybridization （FISH）,fusion genes,and immunophenotype. Results Sixteen of 21 patients carry t（11;19）（q23;p13.1）,showing 11q+ and 19p- derivatives and positive MLL/ELL fusion genes. Seven males and nine females were definitively diagnosed,among them,one shows M2 ; 3,M4; and 10,M5. The other 2 cases were CMML. Five of 21 patients were t（11;19）（q23;p13.3）,exhibiting 11q- and 19p+ derivatives and positive MLL/ENL fusion genes. One male and four females were identified,3 cases were classified as proB-ALL,1 as preB-ALL,and 1 as T-ALL. Conclusions The t（11;19）（q23;p13） abnormality is one of the rare and non-random chromosomal translocations. The t（11;19）（q23;p13.1） are mostly seen in the patients with acute myeloid leukemia （AML） in adults. Comparatively,the t（11;19）（q23;p13.3） frequently occurs in the infants and children with malignancies of lymphoid lineage.

Key words: t（11;19）, Leukemia, MLL/ELL, MLL/ENL