Introduction
Is a group of three conditions in which tumors grow in the nervous system. The three types are neurofibromatosis type I (NF1), neurofibromatosis type II (NF2), and schwannomatosis. In NF1 symptoms include light brown spots on the skin, freckles in the armpit and groin, small bumps within nerves, and scoliosis. In NF2, there may be hearing loss, cataracts at a young age, balance problems, flesh colored skin flaps, and muscle wasting. In schwannomatosis there may be pain either in one location or in wide areas of the body. The tumors in NF are generally non-cancerous.
Symptoms
Neurofibromatosis type 1 in early life may cause learning and behavior problems – about 60% of children who have NF1 have mild difficulty in school. Signs the individual might have are as follows:
- Six or more light brown dermatological spots
- At least two neurofibromas
- At least two growths on the eye’s iris
- Abnormal growth of the spine (scoliosis)
People with neurofibromatosis type 2 can exhibit the same type of skin symptoms as type 1, but not necessarily in every case. The symptom most characteristic of NF2 is hearing loss. The hearing loss occurs due to the pressure of tumors on the acoustic nerve. The same pressure can cause headaches, dizziness, and nausea.
The main symptom of schwannomatosis is localized pain. This pain is due to tissues and nerves experiencing more pressure because of nearby tumors.
Cause
The three types of Neurofibromatosis are caused by different mutations on chromosomes. NF1 is caused by a mutation on the NF1 gene on the arm of chromosome 17. NF2 is caused by a mutation on the NF2 tumor suppressor gene on chromosome 22. Schwannomatosis is caused by various mutations on chromosome 22.