In situ hybridization and translocation breakpoint mapping

Abstract
We have performed in situ hybridization of a probe for the λ IGLC constant region to metaphase spreads from two DiGeorge syndrome (DGS)-related chromosomal rearrangements with breakpoints in 22q11. In this study we have demonstrated that the breakpoints are proximal to the λ IGLC constant region cluster. Thus, at the molecular level, DGS-related breakpoints can be distinguished from the 22q11 breakpoint of CML, but not from the 8;22 translocation of Burkitt lymphoma or from the 21;22 translocations that we have previously studied.