Nevus sebaceus is a common congenital skin hamartoma, classically appearing as a yellowhued plaque on the scalp, face, or neck. It is the hallmark lesion of Schimmelpenning/nevus sebaceus syndrome (MIM: 163200), a multisystem disorder that includes a spectrum of central nervous system, ocular, skeletal, and cardiovascular defects. Secondary neoplasms arise within nevus sebaceus at a modest but elevated rate (Moody et al, 2012), prompting disagreement about whether they should be routinely excised (Shwayder, 2011). Determining the pathogenesis of nevus sebaceus would provide a framework to better understand this lesion and its associated syndrome.

The appearance of nevus sebaceus along Blaschko’s lines suggests that a mosaic genetic mutation causes the lesion, with more extensive multisystem involvement potentially underlying the syndromic form (Happle, 1993). Here, we report a case of an individual with nevus sebaceus syndrome. As individuals with this syndrome are uncommon, we sought to identify associated mutations by comparing the exome sequence of the nevus sebaceus from our patient with those of sporadic nevus sebaceus.