Analysis of reciprocal translocations by chromosome painting: applications and limitations of the technique.

Fluorescent in situ hybridization with chromosome-specific DNA libraries (chromosome painting) is an important new method for assessing chromosome rearrangements. In the research presented in this paper, two familial reciprocal translocations have been studied in the balanced and unbalanced forms, using both traditional G-banding techniques and chromosome painting. Although for each case two chromosomes were involved in the rearrangement, we found that only one chromosome library was suitable for detecting the translocation. These findings illustrate both the potential and the limitations of chromosome painting as a diagnostic tool in cytogenetics.