Cytogenetic features of 5q deletion and 5q-syndrome in myelodysplastic syndrome in Korea; marker chromosomes proved to be chromosome 5 with interstitial deletion by fluorescence in situ hybridization

Abstract

We characterized the cytogenetic changes and prognostic characteristics of 133 Korean patients with myelodysplastic syndrome (MDS), focusing on 5q- syndrome and MDS with chromosome abnormalities involving 5q deletion according to World Health Organization 2008 classification. In all patients, G banding and fluorescence in situ hybridization for 5q were performed, and in MDS patients with 5q deletion, the deleted region on chromosome 5 was mapped with fluorescence in situ hybridization for EGR1, CSF1R, and PDGFRB. The frequency of isolated del(5q) syndrome and 5q deletion was 2.2% (3 of 137 patients) and 15.3% (21 of 137 patients), respectively. International Prognostic Scoring System (IPSS) groups were low risk (5.8%), intermediate 1(51.1%), intermediate 2 (27.8%), and high risk (15.3%). The patients with del(5q) were significantly older (62 years) and showed an unfavorable survival compared to patients without del(5q). Half (53%) of the patients with del(5q) also had complex chromosome abnormalities, including chromosome 7 abnormalities. Of the patients with del(5q), 93.3% were deleted for all three regions on 5q, compared to 66.7% of patients with isolated del(5q). Marker chromosomes proved to be chromosome 5 with interstitial deletion of q arm by fluorescence in situ hybridization in three patients. The biological characteristics of MDS in Korea seem to be markedly different from those of Caucasians, with Koreans having a younger age, lower frequencies of 5q- syndrome, higher frequencies ofcomplex cytogenetic abnormalities including del(5q), and poorer prognosis. We infer that additional chromosome abnormalities contribute to the adverse prognostic impact in patients with del (5q). (C) 2010 Elsevier Inc. All rights reserved.