Neurofibromatosis type 1
This is the most common form of neurofibromatosis. Its symptoms include:
- Six or more brown spots (know as cafe-au-lait spots) on the skin measuring more than 5 millimeters in children and more than 15 millimeters in adolescents
- Two or more neurofibromas (slow-growing tumors of the nervous system) or one plexiform neurofibroma (peripheral nerve tumor), which can cause disfigurement
- Freckling in armpit or groin areas
- An optic glioma, a type of tumor affecting the optic nerves or where the nerves cross
- Two or more growths on the iris of the eye, known as Lisch nodules
- Skeletal or spinal abnormalities such as scoliosis or thinning of the shin bone
- Family history of NF1
- Larger than normal head circumference
- Higher-than-normal rates of epilepsy
- Higher-than-normal rates of ADHD and learning disabilities.
Some of these symptoms, like Lisch nodules and freckling, can be seen at birth. NF1 almost always appears by the time a person is 10 years old.
Neurofibromatosis type 2
NF2 is distinguished by tumors that grow on the hearing nerves. This can lead to partial or complete deafness, a ringing in the ears or balance problems. The disease usually manifests between the ages of 18 and 22.
This form of the disease is genetically distinct from NF1 and NF2. It has only recently been recognized as a separate condition, so not as much is known about it. This condition results in growths known as schwannomas, a type of benign nerve cell tumor. These growths can occur anywhere on the body except on the vestibular nerve, a nerve in the inner ear that is important to balance. Schwannomatosis can result in sometimes-serious pain caused by the growths pressing on nerves and surrounding tissue.