T(1221) - A NEW RECURRENT TRANSLOCATION IN ACUTE LYMPHOBLASTIC-LEUKEMIA

A t(12;21)(p11-p12;q22) was detected by chromosome painting in three p atients with acute lymphoblastic leukemia (ALL) among eight ALL cases with 12p- abnormalities. The three leukemias had similar immunophenoty pes (DR+, CD10+, CD19+). Fluorescence in situ hybridization (FISH) exp eriments using YAC clones from 21q21-q22 were performed to better loca lize the breakpoint on chromosome 21. This breakpoint was localized to 21q22.2 in one patient. Although only one case of ALL with t(12;21) h as been reported previously, the present results suggest that ttl 2;2 1) is a recurrent translocation in ALL. (C) 1994 Wiley-Liss, Inc.