Neurofibromatosis

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. 

 

• Light brown spots on the skin
• Freckling in the armpits or groin area
• Lisch nodules on the iris of the eye
• Soft and pea-sized lumps on or under the skin (neurofibromas)
• Deformities in bones
• A tumor development along the optic nerve (optic glioma)
• Learning disabilities
• Head size larger than average
• Short stature or below average height

 

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:

 

• Gradual hearing loss
• Ringing sensation in the ears
• Poor balance or coordination
• Mild to moderate headaches
• Cataract
• Dizziness

 

Symptoms of Schwannomatosis

 

• Long-term pain from enlarging tumor that can occur anywhere in the body
• Numbness and tingling in toes & fingers
• Weakness in arms or legs
• Loss of muscle strength

 

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

 

Complications of neurofibromatosis can vary even within the same family members and also vary depending upon the types. 

 

Complications: NF1

 

• Neurological problems
• Concerns with appearance
• Skeletal problems
• Vision problems
• Problems during hormonal changes
• Cardiovascular problems
• Breathing problems
• Benign adrenal gland tumor (pheochromocytoma)

 

Complications: NF2

 

• Partial or total hearing loss
• Vision issues
• Facial nerve damage
• Tiny benign skin tumors (skin schwannomas)
• Weakness and numbness in the body especially in the legs and arms
• Several benign brain tumors or spinal tumors (meningiomas)

 

Complications: Schwannomatosis

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.

Imaging tests like X-rays, CT scans, or MRIs can help detect bone abnormalities, tumors in the brain or the spinal cord.

Genetic tests help to identify the cause and type of neurofibromatosis.

Sources:
https://www.mayoclinic.org/diseases-conditions/neurofibromatosis/symptoms-causes/syc-20350490#:~:text=Neurofibromatosis%20is%20a%20genetic%20disorder,in%20childhood%20or%20early%20adulthood.
https://www.webmd.com/pain-management/neurofibromatosis#1