We found that the mutational mechanisms generating CNVs vary depending on the different size of the genomic alteration. NAHR has more of a role in larger CNV formation, whereas VNTR and dispersed duplications (whose role in CNV formation was previously under-appreciated) are more commonly observed with smaller CNVs. Although some sequence motifs (for example, some non-B-DNA structures) were more mutagenic than others, the sequence context was not strongly predictive of the location of CNVs, unlike the link between segmental duplications and larger CNVs mediated by NAHR.
