Clinical, haematological and molecular studies in patients with chromosome translocation t(7;11): A study of four Chinese patients in Taiwan

Translocation t(7;11)(p15;p15) is an uncommon but recurrent chromosome aberration in acute myeloid leukaemia (AML), which occurs mostly in oriental patients and in AML M2 or, occasionally, M4 subtype. Recently, a consistent chimaeric fusion transcript NUP98-HOXA9 was found in several cases of t(7;11). Four AML cases with the chromosome abnormality in Taiwan are described. They were all adults with ages ranging from 30 to 41 years (median 36 years). Three of them were diagnosed as having AML M2; the remaining one as M4. Marked dyserythropoiesis was demonstrated in two patients. All four patients showed pan-myeloid antigen CD13 on the leukaemic cells, but none coexpressed lymphocyte-associated antigens and neither of the two patients studied for CD34 expression had positive staining. NUP98-HOXA9 fusion transcript was detected in both patients who had molecular analysis and the breakpoints on chromosome 11 and 7 respectively were similar to those previously reported. They all received conventional induction chemotherapy, but only one achieved a complete remission (CR) with short duration. This study and others reported in the literature suggest a racial or geographical predisposition among oriental patients to AML with t(7;11) and that this is associated with a poor prognosis. The molecular detection of NUP98-HOXA9 fusion transcript would be a useful method for the diagnosis of t(7;11) and also for monitoring disease status after treatment.