We conducted Sanger-sequencing-based validation for all de novo variants predicted in TD probands and observed confirmation rates of 97.2% in the TIC Genetics trios (97.8% for SNVs and 60% for indels). We did not do so in SSC controls, and consequently, for all burden analyses, we compared unconfirmed de novo variants identified using identical methods from both cohorts. For analysis of recurrent mutations in probands, we relied solely on confirmed variants. See Table S2 for detailed annotations of each predicted de novo variant, including validation status.
