We also estimated the theoretical number of variants per individual (exome) based on the total size of RefSeq hg19 coding intervals (33,828,798 bp); this is shown as a second axis on the same plots (Figures 2A and 2B). We reasoned this would provide a second and potentially more accurate comparison metric versus the rate of observed de novo variants per individual because the callable exome differed by cohort (Figure S3). The theoretical rate also has the advantage of providing an estimate of the total number of expected de novo variants under 100% coverage, as opposed to the number of observed variants per individual, and is therefore a useful metric for comparing across sequencing studies.
