Detection of unidentified chromosome abnormalities in human neuroblastoma by spectral karyotyping (SKY)

Spectral karyotyping (SKY) is a novel technique based on the simultaneous h ybridization of 24 fluorescently labeled chromosome painting probes, It pro vides a valuable addition to the investigation of many tumors that can be d ifficult to define by conventional banding techniques. One such tumor is ne uroblastoma, which is often characterized by poor chromosome morphology and complex karyotypes, Ten primary neuroblastoma tumor samples initially anal yzed by G-banding were analyzed by SKY. In 8/10 tumors, we were able to obt ain additional cytogenetic information. This included the identification of complex rearrangements and material of previously unknown origin. Structur ally rearranged chromosomes can be identified even in highly condensed meta phase chromosomes. Following the SKY results, the G-banding findings were r eevaluated, and the combination of the two techniques resulted in a more ac curate karyotype. This combination allows identification not only of materi al gained and lost, but also of breakpoints and chromosomal associations. T he use of SKY is therefore a powerful tool in the genetic characterization of neuroblastoma and can contribute to a better understanding of the molecu lar events associated with this tumor. (C) 2001 Wiley-Liss, Inc.