[New chromosome abnormality in chronic myeloid leukemia].

A case of chronic myelogenous leukemia with myelofibrosis and failure to respond to busulfan therapy has been reported. An abnormal clone with a rearrangement of four chromosomes, 46, XX, t(1;9) (q21; q24), t(6;22) (q26;q11) was observed. The possible significance of these chromosome abnormalities which are different from the t(9;22) translocation in C.M.L. is discussed.