Neurofibromatosis is not a single medical disorder. It refers to three different conditions involving the development of tumors that may affect the brain, spinal cord, and the nerves that send signals between the brain and spinal cord and all other parts of the body. Most tumors are non-cancerous benign , although some may become cancerous malignant.
Neurofibromatosis 1 NF1 is the most common of the three conditions. Although many people with NF1 inherit the gene that causes the condition, between 30 and 50 percent of cases arise from a spontaneous genetic mutation in the NF1 gene.
Once this mutation has occurred, the abnormal gene can be inherited. Each child of an affected parent has a 50 percent chance of inheriting the gene mutation. Children and adults with NF1 can have a variety of symptoms and medical problems that can change across a lifespan. Most people with NF1 have an average life expectancy. Because many of the other clinical features of NF1 develop as an individual ages, getting the correct diagnosis may take several years. Neurofibromatosis 2 NF2 is less common than NF1.
Approximately 50 percent of affected people inherit the gene familial ; in others, however, the condition is caused by a spontaneous genetic mutation in the NF2 gene. Each child of an affected parent has a 50 percent chance inheriting the abnormal NF2 gene. While teenagers and adults often are first seen for hearing and balance problems, young children with NF2 more commonly seek initial medical attention due to vision problems and meningiomas. Signs of NF2 may be present in childhood but can be overlooked, especially in children who do not have a family history of NF2.
Children are often first seen by a doctor because of schwannomas in the skin, vision loss from retinal abnormalities or tumors, seizures, or weakness related to spinal cord compression.
