๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
INTRODUCTION
Neurofibromatosis (NF) and tuberous sclerosis complex (TSC) are neurocutaneous disorders, or phakomatoses. They are characterized by cutaneous lesions as well as peripheral and/or central nervous system neoplasms. Like most hereditary cancer syndromes, NF and TSC are autosomal dominant in inheritance. Despite a high penetrance for both diseases, new cases of NF type 1 (NF1) and TSC frequently represent de novo mutations. The pleiotropic nature of these two neurocutaยญ neous syndromes has led to complex schemes for their classification and diagnosis. Dermatologists are frequently asked to participate in the clinical diagnosis of patients with NF1 and TSC due to the early appearance of cutaneous, especially pigmentary, findings. Advances in the molecular characterization of these disorders have revealed related, but distinct, pathogenic mechanisms.
In 1982, Riccardi proposed a classification scheme for patients with NF that included seven subtypes. Elucidation of the molecular bases of NF1, NF2, mosaic/segmental NF1 (formerly known as NF5), and โNF1-likeโ syndromes has further refined the categorization of patients. Among these conditions, NF1 has the most well-characterized and diagnostic skin findings and is the main focus in this chapter.