Neurofibromatoses are a group of genetic disorders that lead to the formation of tumors on nerve tissue. These tumors can grow anywhere in the nervous system, including the brain, spinal cord, and nerves. There are three types of neurofibromatosis: neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis. NF1 is usually diagnosed in childhood, while NF2 and schwannomatosis are usually diagnosed in early adulthood.
Tumors in these diseases are usually not cancerous (benign), but can sometimes become cancerous (malignant). The symptoms are often mild. However, complications from neurofibromatosis can include hearing loss, learning difficulties, cardiovascular (cardiovascular) problems, loss of vision, and severe pain. Neurofibromatosis Treatment in Hyderabad
There are three types of neurofibromatosis, each with different signs and symptoms.
Neurofibromatosis 1 (NF1) is usually diagnosed in childhood. The signs are often evident at birth or shortly thereafter, and almost always by the age of 10. The signs and symptoms are often mild to moderate in severity, but can vary in severity.
Signs and symptoms are:
- Flat, light brown spots on the skin (café au lait spots). These harmless spots are common in many people. Having more than six café-au-lait spots suggests NF1. They are usually present at birth or appear in the first few years of life. No new spots appear after childhood.
- Freckles in the armpits or in the groin. Freckles usually appear between the ages of 3 and 5 years. Freckles are smaller than spots in the café au lait and tend to form in clusters in folds of skin.
Neurofibromatosis is caused by genetic abnormalities (mutations) that are passed on from a parent or that occur spontaneously at conception.
The specific genes involved depend on the type of neurofibromatosis:
- NF1. The NF1 gene is on chromosome 17. This gene produces a protein called neurofibromin, which helps regulate cell growth. The mutated gene causes a loss of neurofibromin, which can cause cells to run out of control.
- NF2. The NF2 gene is located on chromosome 22 and produces a protein called merlin (also called schwannomine) that suppresses tumors. The mutated gene causes a loss of merlin, which leads to uncontrolled cell growth.
- Schwannomatosis. So far it is known that two genes cause schwannomatosis. Mutations in the SMARCB1 and LZTR1 genes that suppress tumors have been linked to this type of neurofibromatosis. Neurofibromatosis Treatment in Hyderabad
Autosomal dominant inheritance model
Autosomal Dominant Inheritance PatternOpen Context Dialog
The biggest risk factor for neurofibromatosis is a family history of the disease. About half of people with NF1 and NF2 inherited the disease from an affected relative. People with NF1 and NF2 whose relatives are unaffected are likely to have a new genetic mutation.
NF1 and NF2 are both autosomal dominant disorders, meaning that every child from one of the parents affected by the disorder has a 50% chance of inheriting the genetic mutation.
The inheritance pattern of schwannomatosis is less clear. The researchers currently estimate that the risk of inheriting schwannomatosis from an affected parent is around 15%.
The complications of neurofibromatosis even vary within the same family. Usually complications result from tumors that affect nerve tissue or put pressure on internal organs.
Complications from NF1 include:
Neurological problems. Learning and thinking difficulties are the most common neurological problems associated with NF1. Rare complications include epilepsy and the accumulation of excess fluid in the brain.
Appearance problems. Visible signs of neurofibromatosis – such as extensive café-au-lait spots, numerous facial neurofibromas, or large neurofibromas – can cause anxiety and emotional distress, although not medically severe.
Skeletal problems. Some children have abnormally shaped bones, which can cause curvatures in the legs and fractures that sometimes don’t heal. NF1 can cause a curvature of the spine (scoliosis) that may require bracing or surgery. NF1 is also linked to a decrease in bone mineral density, which increases the risk of weak bones.