Neurofibromatosis is a rare genetic disorder characterized by tumor growth in the nerve tissues and other parts of the body. These tumors can grow anywhere in the nervous system, including the brain, spinal cord, and nerves. Neurofibromatosis is generally diagnosed in childhood or early adulthood and affects the growth and development of the nerve cells and tissues. It is not a single disorder in itself, but refers to a set of three different conditions: Neurofibromatosis 1 (NF 1), Neurofibromatosis 2 (NF 2) & Schwannomatosis. The tumor formation in this disorder is usually noncancerous (benign) but sometimes may turn out to be cancerous (malignant) as well. This leads to severe complications such as neurological problems, vision and hearing issues. Timely management & treatment of neurofibromatosis helps to reduce further complications, and aids in healthy growth & development in children.
Types of Neurofibromatosis
1. Type 1 or NF1: It causes skin changes and deformed bones. NF1 usually starts in childhood. Sometimes the symptoms are noticeable at birth or shortly afterward.
2. Type 2 or NF2: It causes hearing loss, ringing in the ears, and poor balance in the person. NF2 is characterized by multiple tumors in the cranial or spinal nerves and is less common than NF1.
3. Schwannomatosis: It is the rarest type of neurofibromatosis and is characterized by causing intense pain. This disorder generally affects people after the age of 20. It causes tumor formation on the cranial, spinal, and peripheral nerves. However, it hardly affects the nerve that carries sound and balance signaling from the inner ear to the brain, so it doesn't cause hearing loss.
Signs and Symptoms related to Neurofibromatosis
Symptoms of Neurofibromatosis 1
Symptoms of NF1 are noticeable at birth or in early childhood.
Symptoms of Neurofibromatosis 2
Signs and symptoms, in this case, are generally observed in the late teen and early adulthood and can vary in its severity. Signs and symptoms include:
Symptoms of Schwannomatosis
Causes of Neurofibromatosis
The major cause of neurofibromatosis is genetic defects or mutations that are passed on by a family or spontaneously at conception. The mutation in the genes entirely depends upon the type of neurofibromatosis:
1. NF1- This gene produces a protein known as neurofibromin that helps regulate cell growth. The mutated gene can result in the loss of neurofibromin, which allows cells to grow at an uncontrollable rate.
2. NF2- This gene produces a protein called merlin (also called schwannomin), which is responsible for suppressing the tumors. The mutation in this gene causes loss of merlin, leading to the uncontrolled growth of cells.
3. Schwannomatosis- Mutations of two genes SMARCB1 and LZTR1, which suppress tumors, are linked with this type of neurofibromatosis.
Complications of neurofibromatosis can vary even within the same family members and also vary depending upon the types.
The pain caused by schwannomatosis can be impairing and may need surgical intervention in certain cases.
Diagnosis of Neurofibromatosis
For diagnosing neurofibromatosis, the doctor might start by reviewing personal and family medical history along with a physical examination. Some additional tests might be required to diagnose NF1, NF2, or schwannomatosis as well:
An eye examination to detect lisch nodules, cataracts, and vision problems
Hearing and balance examination.
Genetic tests help to identify the cause and type of neurofibromatosis.