CLARIFICATION OF SUBTLE RECIPROCAL REARRANGEMENTS USING FLUORESCENCE IN-SITU HYBRIDIZATION

Fluorescence in situ hybridization (FISH) using chromosome-specific DN A libraries as painting probes was applied in the analysis of six subt le, balanced chromosome rearrangements. Both fresh and older slides, s ome of which had been previously G-banded, were used to determine if F ISH could identify unambiguously very small amounts of translocated ma terial. Our results indicate that this procedure can clearly and preci sely distinguish the specific components of extremely subtle transloca tions, in different cell types, such as leukocytes, aminocytes, and ch orionic villus, and irregardless of preparation age. This ability make s FISH a valuable tool in clinical cytogenetics for the confirmation o f preliminary G-banded karyotypes. (C) 1993 Wiley-Liss, Inc.