Whole arm translocation t(17;18): a non-random abnormality of myeloid cell proliferation

Whole arm translocation t(17;18) was detected in two patients, one with acute monocytic leukemia and the other with acute transformation of chronic myelocytic leukemia. Dual-color fluorescence in situ hybridization (FISH) to interphase nuclei with alphoid probes specific to chromosomes 17 and 18 showed the presence of two very close spots. This feature was interpreted as the conservation of the pericentromeric region of the two chromosomes involved in the translocation. The present cases add to eight previously reported other patients with whole arm translocation t(17;18) (one with FISH studies). Since these patients had either myeloid leukemia or myelodysplastic syndrome, it is suggested that the t(17;18)(p10;q10) translocation is a new non-random abnormality associated with myeloid cell proliferations.