Figure 7

Features that characterize variants that activate de novo ectopic splice sites ('ectopic SAVs'). (a) Most ectopic SAVs, in contrast to hSNPs and skipping SAVs, have a large ΔSS value and create an ectopic splice site that is stronger than the natural splice site. (b) Hexamers in the vicinity of the splice junctions are largely made up of ESSs. The graph represents the proportion of positions occupied either by an ESE or ESS motif across approximately 25,000 internal exons. Each position on the graph represents the first base of a hexamer sliding across 100 bp of the upstream and downstream introns and the first and last 50 bp of the exon. (c) Ectopic SAVs are located predominantly in the vicinity of the splice site of the same type created, that is, the majority of ectopic splice sites created are 5' ectopic sites and are located towards the end of the exon close to the 5' splice site. hSNPs that create a strong ectopic splice site computationally ('ectopic-like' hSNPs) are distributed across the exon in quite the opposite way, indicating the same constraints do not apply to these variants.