Acquired partial duplication or triplication of the long arm of human chromosome 1 has been observed rarely in myelodysplastic syndrome(MDS). We describe a dup(1)(q21q32), trp(1)(q21q32) in a patient with refractory anemia of MDS. A 51-year-old man was admitted for dyspnea. Five months ago, he was diagnosed with myelodysplastic syndrome (RA) and iron deficiency anemia and had been treated with iron vitamin Bl2, oxymetholone, and prednisolone. The karyotype of trypsin-Giemsa-banded metaphase cells obtained from bone marrow aspirates was
46,XY,dup(1)(q21q32)×2[5]/46,XY,try(1)(q21q32)[2]/46,XY,dup(1)(q21q32),trp(1)(q21q32)[2] and confirmed the amplification of 1q21-lq32 by CGH (comparative genomic
hybridization). In this assay, test and reference DNAs are labeled with FITC and Texas Red, respectively and co-hybridized to normal metaphase chromosomes. Ratio profiles of each individual chromosome were analyzed using a Quips-XL software(Vysis, Downers Grove, IL, USA). The thresholds of gain and loss were defined 1.2 and 0.8, respectively.