Reassessment of two apparent deletions of chromosome 16p to an ins(11;16) and a t(1;16) by chromosome painting.

Two apparent deletions of the short arm of chromosome 16 were studied by in situ hybridisation using biotinylated DNA from a chromosome 16 specific cosmid library (chromosome painting). One abnormality was delineated as a t(1;16)(p36;p12) and the other as a ins(11;16)(q13;p13.13p13.3). Apparently unbalanced de novo abnormalities detected by classical cytogenetic procedures should be interpreted with caution. In situ hybridization using DNA from chromosome specific libraries provides the appropriate technology to delineate such abnormalities.