Various types of neurofibromatosis have been described. They all exhibit the formation of neurofibromas, which are tumors arising from the nerve sheath. Chromosomal genetic mutations have been described for each with hereditary predilection.
Type 1 Neurofibromatosis
This is the most common form of neurofibromatosis with approximately 1 in 3000 individuals in the US affected. Common signs include café-au-lait birthmarks, freckling, optic gliomas, and neurofibroma tumors. Surgery is currently the only definitive treatment available.
Type 2 Neurofibromatosis
This more rare form of neurofibromatosis affects the central nervous system and results from a different chromosome gene mutation than NF-1. The main characteristic is the presence of vestibular schwannomas on both 8th cranial nerves.
Schwannomatosis
This is a more recently described rare form of neurofibromatosis. It involves extensive, body-wide formation of neurofibromas on major peripheral nerves. Skin findings do not occur as with NF-1 and vestibular schwannomas similar to NF-2 are absent.