<unk>  <unk>  is a group of three conditions in which tumors grow in the nervous system. The three types are<unk>  type I <unk> 1),<unk>  type II <unk> 2), and schwannomatosis. In<unk> 1 symptoms include light brown spots on the skin, freckles in the armpit and groin, small bumps within nerves, and scoliosis. In<unk> 2, 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<unk>  are generally non-cancerous. The cause is a genetic mutation in certain oncogenes. These can be inherited from a person's parents, or in about half of cases spontaneously occur during early development. Different mutations result in the three types of<unk> .<unk>  arise from the supporting cells of the nervous system rather than the neurons themselves. In<unk> 1, the tumors are neurofibromas (tumors of the peripheral nerves), while in<unk> 2 and schwannomatosis tumors of Schwann cells are more common. Diagnosis is typically based on symptoms, examination, medical imaging, and biopsy. Genetic testing may rarely be done to support the diagnosis. There is no known prevention or cure. Surgery may be done to remove tumors that are causing problems or have become cancerous. Radiation and chemotherapy may also be used if cancer occurs. A cochlear implant or auditory brainstem implant may help some who have hearing loss due to the condition. In the United States, about 1 in 3,500 people have<unk> 1 and 1 in 25,000 have<unk> 2. Males and females are affected equally often. In<unk> 1, symptoms are often present at birth or develop before 10 years of age. While the condition typically worsens with time, most people with<unk> 1 have a normal life expectancy. In<unk> 2, symptoms may not become apparent until early adulthood.<unk> 2 increases the risk of early death. Descriptions of the condition occur as far back as the 1st century. It was formally described by Friedrich Daniel von Recklinghausen in 1882, after whom it was previously named.
Neurofibromatosis
Tuberous sclerosis
Fox–Fordyce disease
Ollier disease
Irlen syndrome
Progeria
Fabry disease
Degos disease