Architecture of structural variants. (a) Simple SVs: deletion (Del), insertion (Ins), inversion (Inv), tandem duplication (tandem Dup) and other types of copy number gains. Linked gain is a small copy number gain at close proximity to its copy. Inverted linked gain (not drawn) is similar to a linked gain but the copy is inverted. Del+Nml+Del is two deletions separated by a normal copy of small size. (b) Complex SVs: deletion co-occurring with insertion (Del+Ins), inversion with flanking deletions (Del(s)+Inv), inversion with insertion (Inv+Ins), deletion within a copy number gain (Del in gain) and inversion within a copy number gain (Inv in gain).