High-throughput sequencing now allows researchers to identify patterns of rearrangement in tumour genomes, and has led to the discovery of Complex Genomic Rearrangements (CGRs) as a new cytogenetic feature of some cancers. Closed chain breakage and rejoining (CCBR), a generalization of reciprocal translocation, was recently identified in prostate cancer . CCBRs involve the balanced rearrangement of some
loci, and thus have the potential to fuse or interrupt up to
genes. In addition, dispersed throughout some breast cancer genomes are ‘genomic shards’, small fragments of DNA originating from elsewhere in the genome and inserted at the breakpoints of larger scale rearrangements.