Depiction of the strategy used for assigning genomic coordinates to complex SV events. Coordinates within our database BreakDB are stored in a recursive fashion, if multiple SVs with partially overlapping coordinates occurred within a single haplotype. In particular, where a coordinate is typically defined with respect to the reference genome, it can also be defined in respect to other SVs, as indicated in the scheme depicted in the figure. For example, an insertion event can take place within an earlier insertion event, affecting the same haplotype the earlier event occurred in. If coordinates for the second insertion event were reported merely relative to the human reference genome, positional information for the SV would be lost. BreakDB therefore reports both coordinates within the ancestral ('parent') event, but can also trace back all the way to the reference coordinates.
Korbel et al. Genome Biology 2009 10:R23 doi:10.1186/gb-2009-10-2-r23