Multiplex fluorescence in situ hybridization and cross species color banding of a case of chronic myeloid leukemia in blastic crisis with a complex Philadelphia translocation

Exciting neu techniques in molecular cytogenetics-namely, spectral karyotyp ing, multiplex fluorescence in situ hybridization (M-FISH), and cross speci es color banding-have been recently developed. An increasing number of repo rts demonstrate the success of these procedures in providing additional cyt ogenetic information-identifying marker chromosomes and revealing the prese nce of previously undetected chromosomal changes. However, these procedures have their limitations, and their absolute sensitivity in the accurate ide ntification of subtle chromosomal abnormalities remains to be established. M-FISH and color banding have been applied to a case of chronic myeloid leu kemia with a complex Philadelphia translocation involving chromosomes 9, 17 , and 22, which had initially been identified from G-banded chromosome anal ysis. The abnormalities were confirmed by chromosome "painting" and specifi c probes. Although M-FISH and color banding revealed no additional cryptic chromosomal changes, this study has clearly demonstrated the success of the se multiple color FISH approaches in the accurate characterization of a com plex rearrangement with subtle abnormalities. (C) Elsevier Science Inc., 19 99. All rights reversed.