Todman’s 2008 proposal that the hereditary lesions of the Arsacid Dynasty were due to neurofibromatosis remains the strongest theory. Neurofibromatosis includes neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2), which are both autosomal dominant and share common clinical features “including hyperpigmented birthmarks of the skin” [13]. The gene discussed is NF1; the disease is neurofibromatosis type 1.