Identification of multiple copies of a 20q-chromosome in a case of myelodysplastic syndrome: a FISH study

In myelodysplastic syndromes (MDS) karyotypic aberrations identify subgroup s of patients with distinct clinical-morphological features and can be rele vant in risk assessment of developing leukemia. Often conventional cytogene tic analysis is not sufficiently informative due to the presence of partial ly or completely unrecognizable chromosome markers. By chromosome microdiss ection (MD) and fluorescence in situ hybridization (FISH) we investigated t he nature of a karyotypic marker occurring in multiple copies in one case o f MDS arisen in a patient previously treated for breast cancer. Results sho wed dicentrics derived from telomeric fusion between interstitially deleted 20q-chromosomes. The abnormal karyotype resulted into polysomy for a delet ed chromosome 20q. (C) 1999 Elsevier Science Ltd. All rights reserved.