Constitutional t(5;7)(q11;p15) rearranged to acquire monosomy7q and trisomy 1q in a patient with myelodysplastic syndrome transforming to acute myelocytic leukemia

We report the case of a 61-year-old woman who presented with a myelodysplastic syndrome (MDS) and a t(5;7)(q11.2;p15) in her bone marrow cells. Subsequent analysis of phytohemagglutinin-stimulated peripheral blood lymphocytes and cultured skin fibroblasts showed that the translocation was constitutional. Disruption of chromosome bands 5q11.2 and 7p15 has been described recurrently in MDS and acute myelocytic leukemia (AML) and, although the age of onset was not earlier than usual, it is nonetheless possible that genes interrupted by this translocation may been a predisposing factor for her condition. With progression to AML, a further rearrangement of the constitutional der(7)t(5;7) occurred, involving chromosome arm 1q. Fluorescence in situ hybridization (FISH) with whole-chromosome paints showed that the result of the second rearrangement, a t(1;7)(q32.1;q32), was observed, leading to trisomy of the segment 1q32.1∼qter and monosomy of the segment 7q32.1∼qter. The acquired imbalances, particularly loss of 7q, are commonly associated with MDS/AML and a poor prognosis; however, this patient remained in remission after treatment for more than two years before AML relapse, perhaps because the affected regions fall outside of the critical regions of imbalance.