[Detection of 20q(-) chromosome abnormality in myelodysplastic syndrome by interphase fluorescence in situ hybridization].

In order to explore the value of interphase fluorescence in situ hybridization (FISH) in the detection of partial deletion of the long arm of chromosome 20 (20q(-)) in patients with myelodysplastic syndrome (MDS), spectrum Green fluorescein directly labeled yeast artificial chromosome (YAC) clone 912C3 which spans the breakpoint cluster region in band 20q12 was used as probes to perform interphase FISH on the marrow cells from 52 cases of MDS and 5 normal controls. 200 to 300 cells were scored for each case and cases which had cells with a green hybridization signal>7.16% were defined as 20q(-) positive. The results of FISH were compared with those of conventional cytogenetics (CC) assay. The results showed that among 52 cases of MDS, 7 (13.5%) cases were positive by FISH, however, of which, 4 cases were positive and the other 3 cases were negative by CC assay. It is concluded that YAC912C3 and interphase FISH providing a powerful technique in the detection of 20q(-) in MDS is an important complement to CC assay.