Jumping translocation of 1q in a BCR/ABL-positive acute lymphoblastic leukemia.

Jumping translocations (JT) are rare chromosomal abnormalities in which an identical copy of a chromosomal region (donor) is translocated to a different chromosome (acceptor). Chromosome 1 is often involved as donor chromosome. JTs of the long arm of chromosome 1 (1q) or parts of it are associated with a poor outcome. We report on a 72-year-old male patient with a BCR/ABL1 rearrangement positive acute lymphoblastic leukemia (common ALL, or c-ALL; FAB L2 morphology) and with additional structural and numeric aberrations. Four aberrant clones were observed after conventional cytogenetic analysis. Three of the four clones showed a JT with 1q as donor and 3q, 8q, and 22q as acceptors. To the best of our knowledge, neither JT between 1q and chromosome 3 nor JT between 1q and chromosome 22 have been described in c-ALL. This report emphasizes the frequent involvement of 1q in JT and the association with a poor prognosis.