We estimated the theoretical rate of coding de novo variants per child by multiplying the per bp mutation rate by the size of the RefSeq hg19 coding exome (33,828,798 bp; see “Definition of Coding Portion of Exome”). We then determined the mean mutation rate per cohort. Again, we estimated the 95% CI in R using the t.test function with one vector of data corresponding to the individual mutation rates. We obtained an identical estimate by simply multiplying the mean mutation rate per bp by the size of the coding exome.
