Fig. 1.

Sebaceous carcinomas are distinguished by somatic mutation burden and type into pauci-mutational, MSI, and UV-damage categories. a Total numbers of SSNVs (blue) and indels (red) are shown for each of 32 SeC in this study. Pauci-mutational SeC (samples 1–13) show a mutation rate ranging from 1.2 to 5.2 per Mb, while MSI and UV tumors reach rates of 82.6 and 586 per Mb, respectively. Nine of the 13 pauci-mutational tumors (samples 1–9) represent all 9 ocular SeC sequenced in this report. b The percentage of mutations demonstrating each of the Stratton mutational signatures are shown, for signatures present in at least 10% of mutations of at least one sample. High frequency of DNA damage mutations (signatures 6 and 15 in red and orange, respectively) vs. UV-damage signatures (7 and 11 in darker blue and lighter blue, respectively) distinguish SeC. The color key further details other mutational signatures in these samples. While mutations associated with normal aging (signature 1) are sparse in the UV subclass, they represent the single largest class detected in the pauci-mutational cancers. Somatic mismatch repair mutations in MSI tumors are labelled