What is Neurofibromatosis

Even though the condition is on of the most common disorders in the world, affecting 1 in 3000 people to some degree. It is also one of the most unknown disorders, even though we all may see people with the condition and just think it is a birthmark. So I thought, I would use this post to discuss the condition itself in general to help readers to better understand it.

photo by Kevin Surbaugh
of his own left arm

According to the Mayo Clinic, Neurofibromatosis (NF) is a horrible genetic disorder that disturbs cell growth in the nervous system, causing tumors to form on nerve tissue. These tumors may develop anywhere in your nervous system, including in your brain, spinal cord and nerves. The Mayo Clinic further states, that Neurofibromatosis is usually diagnosed in childhood or early adulthood. Which would hold true for me. The tumors are usually benign (aka noncancerous), but in some cases these tumors become malignant (aka cancerous) tumors. People with neurofibromatosis often experience only mild symptoms. However, effects of neurofibromatosis can range from hearing loss, learning impairment, and heart and blood vessel (aka cardiovascular) complications to severe disability due to nerve compression by tumors, loss of vision and severe pain. NF can cause symptoms in virtually any organ system in the body. There are three (3) types of Neurofibromatosis, Type 1, Type 2 and Schwannomatosis.

NF1 formally known as von Recklinghausen's disease, is transmitted on chromosome 17 and is mostly caused by mutation (rather than deletion) of the Nf1 gene. Shortly after birth several birthmarks (or hyperpigmentation) may appear in different parts of the body. During late childhood tumors on the skin and perhaps even under the skin may appear, from a few to sometimes even thousands. There is a very slight risk that the tumors become cancerous. For some patients this presents no serious medical problems apart from a skin condition. However, complications are possible, and sometimes serious.

NF2

Neurofibromatosis type 2 (NF2) or bilateral neurofibromatosis, results mainly from a mutation (rather than a deletion) of the Nf2 gene and is transmitted on chromosome 33. Tumors form in the nervous system, generally within the skull, known as intracranial tumors. Tumors also develop in the spinal canal, known as intraspinal tumors. Acoustic neuromas are common - these develop on the vestibulocochlear nerve (the eighth cranial nerve). The vestibulocochlear nerve is responsible for our sense of hearing; it is also important for our sense of balance and body position. Patients may experience hearing loss, as well as losing their sense of balance. Symptoms tend to occur during late teens and early 20s. (I knew of one person who went deaf in high school. In that case they remained in school and the school hired a sign language interpreter to translate the classes.) Tumors may also become cancerous.

Schwannomatosis Schwannomatosis is the rarest of the three types and is estimated to occur in 1 in 40,000 births. The inheritance pattern of Schwannomatosis is not well understood. The risk of transmitting the disorder to offspring is approximately 15%. Schwannomatosis symptoms usually first appear in adulthood. Schwannomatosis is characterized by:
Multiple schwannomas (never sheath tumors) without evidence of vestibular schwannoma, Pain associated with the schwanomas and Symptoms possibly limited to one area of the body. Diagnostic Criteria for Schwannomatosis include:

Individual is age over 30 years

AND has two or more non-intradermal Schwannomas, at least one with histological confirmation

AND has no evidence of vestibular tumor on high-quality MRI scan

AND has no known constitutional NF2 mutation There is no currently accepted medical treatment and/or drug for schwannomatosis, although surgical management is often found to be effective. Pain usually subsides when tumors are removed completely, although it may recur should new tumors form. When surgery isn’t possible, ongoing monitoring and management of pain in a multidisciplinary pain clinic is advisable.