Neurofibromatosis Type 1

Neurofibromatosis type 1 is a genetic disorder caused by mutations in the NF1 gene, a tumor suppressor gene on chromosome 17, that leads to the growth of benign tumors called neurofibromas along nerves throughout the body, along with flat, light brown skin patches known as cafe-au-lait spots, freckling in the armpits and groin, and small growths on the iris called Lisch nodules. It is one of the most common single-gene disorders, affecting roughly one in three thousand people, with severity varying widely even within the same family. German pathologist Friedrich Daniel von Recklinghausen described the condition in detail in 1882, and it was long known by his name before the modern classification separated it into distinct neurofibromatosis types.