Mosaic activating RAS mutations in nevus sebaceus and nevus sebaceus syndrome

Exome sequencing Genomic DNA was isolated using the Qiagen Blood/Tissue kit (Qiagen, Valencia, CA). Exome capture was performed with the Agilent SureSelect All-Exon v2 kit, and 100 bp paired-end library reads were generated on Illumina HiSeq 2000 to a 50-fold target average depth of coverage. Alignment of reads to the human genome was performed with DNAnexus (www.dnanexus.com) and bwa (Li and Durbin, 2009), and small nucleotide variants called by the DNAnexus cancer nucleotide variation algorithm using default parameters, as well as Seqgene (Deng, 2011) with the following parameters: minimum read coverage = 5, minimum percent for variant call = 0.05, minimum Phred-based cutoff for variant bases = 20.