OBJECTIVETo study the myelodysplastic syndrome(MDS) with 1;7 translocation in five cases and to determine further the constitution and origin of centromere of the derivative chromosome resulting from 1;7 translocation.

METHODSBone marrow chromosome preparation of five cases was made using direct method or short- term culture. Karyotypic analysis was carried out by R-banding technique. Dual-color fluorescence in situ hybridization(FISH) using Spectrum Red and Spectrum Green directly labeled chromosome 1-specific a-satellite DNA probe(red) and chromosome 7-specific a-satellite DNA probe(green) was performed in three patients of them.

RESULTSAll of the five cases had 1;7 translocation. The centromere of the derivative chromosome 7p/1q was constituted with red and green signals in three of them.

CONCLUSIONThe result of dual-color FISH confirms that the centromere of the derivative chromosome resulting from 1;7 translocation originated from both centromeres of chromosome 1 and chromosome 7.