Chromosome derived from translocation(1;17) retains alphoid sequences of both chromosomes involved.

Examining a bone marrow (BM) karyotype of a patient with a refractory anemia with excess of blasts (RAEB), we detected a clone with an unbalanced translocation(1;17), resulting in monosomy of 17p and trisomy of 1q. Using fluorescence in situ hybridization (FISH) technique with alpha-satellite DNA probes specific for chromosomes 1 and 17, we observed that the chromosome derived from the translocation shows hybridization signals for both the centromeres of chromosomes 1 and 17. This finding suggests that the breakpoints of the two autosomes involved in the rearrangement occurred in the primary constriction. The case confirms the ability of ISH analysis to detect structural rearrangements in cancer cytogenetics.