Affect on Daily Life

NF1- mild, and individuals live normal and productive lives.

NF2 varies greatly among individuals. In some cases of NF2, the damage to nearby vital 

structures, such as other cranial nerves and the brain stem, can be life-threatening.

Most individuals with schwannomatosis have significant pain.  In some extreme cases the pain will 

be severe and disabling. 

Evans DG, Huson SM, Donnai D, Neary W, Blair V, et al. (1992) A clinical study of type 2 neurofibromatosis. Q J Med 84: 603–618. [PubMed]

National Institutes of Health 

        www.nih.gov

New Research

Several years ago, research teams located the exact position of the NF1 gene on chromosome 17. 

The product of the NF1 gene is a large and complex protein called neurofibromin, which is 

primarily active in nervous cells as a regulator of cell division.  Intensive efforts have led to the 

identification of the NF2 gene on chromosome 22.  

The NF2 gene product is a tumor-suppressor protein called merlin.  Ongoing research continues to 

discover additional genes that appear to play a role in NF-related tumor suppression or growth.  

Other research is aimed at understanding how the genetic mutations that cause the benign tumors of 

NF1 also cause nerve cells and nerve networks to form abnormally during fetal development, which 

later result in the learning disabilities and cognitive deficits of children with the disorder. 

Additional research is aimed at understanding the natural history of tumors in NF2 and 

determining possible factors that may regular their growth patterns.  The Interinstitute Medical 

Genetics Research Program at the NIH Clinical Center conducts NF2 family history research. 

Using specimens from some of the families, scientists have isolated and sequenced the NF2 

gene and have described two different patterns of clinical features in NF2 patients. 

Investigators are continuing to study these patterns to see if they correspond to specific types 

of gene mutations. 

McClatchey AI (2007) Neurofibromatosis. Annu Rev Pathol 2: 191–216. [PubMed]

Courtois-Cox S, Genther Williams SM, Reczek EE, Johnson BW, McGillicuddy LT, et al. (2006) A negative feedback signaling network underlies oncogene-induced senescence. Cancer Cell 10: 459–472.[PMC free article] [PubMed]

Treatment

Surgery is often recommended to remove the tumors.  Some NF1 tumors may become cancerous, and treatment may include surgery, radiation, or chemotherapy. Surgery, radiation, and chemotherapy also may be used to control or reduce the size of optic nerve tumors when vision is threatened.  Some bone malformations can be corrected surgically.

For NF2, improved diagnostic technologies, such as MRI, can reveal tumors as small as a few millimeters in diameter, thus allowing early treatment. Surgery to remove tumors completely is one option but may result in hearing loss. Surgery also can correct cataracts and retinal abnormalities.

There is no currently accepted medical treatment or drug for schwanomatosis, but surgical management is often effective.  Pain usually subsides when tumors are removed completely.  Genetic testing is available for families with documented cases of NF1 and NF2 but such testing for schwannomatosis currently does not exist.  

 Kourea HP, Orlow I, Scheithauer BW, Cordon-Cardo C, Woodruff JM (1999) Deletions of the INK4A gene occur in malignant peripheral nerve sheath tumors but not in neurofibromas. Am J Pathol 155: 1855–1860. [PMC free article] [PubMed]
Holtkamp N, Malzer E, Zietsch J, Okuducu AF, Mucha J, et al. (2008) EGFR and erbB2 in malignant peripheral nerve sheath tumors and implications for targeted therapy. Neuro Oncol 10: 946–957.[PMC free article] [PubMed]

Types

There are 3 different types of Neurofibromatosis: Neurofibromatosis Type 1(NF1), Neurofibromatosis Type 2(NF2), and Schwannomatosis.  In diagnosing NF1, a doctor looks for changes in skin appearanc, tumors, or bone abnormalites, and/or a parent, sibling or child with NF1. It affects about 1 in every 3,000 people, ranges from mild to severe, and can cause more symptoms in some people than others. Next is NF2,  it's the less common form and may be evident to diagnose at birth and nearly always by the time the child is 10yrs old. It affects about 1 in every 25,000 people. Symptoms generally occur in the late teens and early 20's. However, some people experience symptoms in childhood and others not until age 40. Last is Schwanomatosis, which is once considered to be a variation of NF2.  It grows on the peripheral nerves throughout the body, can cause severe, debilitating pain, and neurological dysfunction. Also, it's recognized most often in people over the age of 30. 

www.hopkinsmedicine.org › ... › Neurofibromatosis Center
http://www.nfinc.org

Halder G, Johnson RL. Hippo signaling: growth control and beyond. Development. 2011;138:9–22. doi: 10.1242/dev.045500. [PMC free article] [PubMed] [Cross Ref]

 Lorenzo J, Barton B, Acosta MT, North KN. The mental motor and language development of toddlers with neurofibromatosis type 1. J Pediatr. 2011;158:660–665. doi: 10.1016/j.jpeds.2010.10.001. [PubMed][Cross Ref]

What is this?

Neurofibromatosis is a genetic neurological disorder that causes tumors or neurofibromas to grow in the nervous system. It can affect the brain, spinal cord, nerves, and skin. Neurofibromatosis can either be an inherited disorder or the product of a gene mutation. The majority of the affected people inherit the disorder. After the mutant gene causes the tumors to grow along the body, under the skin, it can be passed along to succeeding generations.

 Neurofibromatosis. MedlinePlus. 2009 Available at: http://www.nlm.nih.gov/medlineplus/neurofibromatosis.html. Accessed February 10, 2010.
Learning About Neurofibromatosis. National Human Genome Research Institute (NHGRI). 2009 Available at: http://www.genome.gov/14514225. Accessed February 10, 2010.