Pattern of trisomy 1q in hematological malignancies: a single institution experience

An extra copy of 1q usually originates from the translocated unbalanced derivative chromosome, isochromosome, or "jumping translocation." We report a pattern of partial trisomies and unbalanced whole-arm translocations of 1q in 10 patients: 5 with myelodysplastic syndrome, 3 with acute myeloid leukemia, and a single patient with acute lymphoblastic leukemia and myeloproliferative syndrome. The trisomy of 1q was registered as the sole karyotype aberration in one patient, while it was accompanied by a limited number of additional chromosomal changes in nine patients. These patients are a subset of a larger group of 92 adults carrying a wide variety of chromosome 1 anomalies within a complex cytogenetic context observed over a period between 1994 and 2006 in a panel of 3,786 hematologic patients at the Institute of Hematology in Belgrade. Conventional cytogenetics was supplemented by fluorescence in situ hybridization with a probe specific for the paracentric region of 1q. Whole-arm 1q translocations involved chromosomes Y, 7, 14, 15, 16, and 19. This study suggests that gain of 1q as the sole cytogenetic abnormality may be sufficiently mutagenic to favor leukemogenesis and hematopoietic tissue degeneration (trilineage myelodysplasia).