||This article contains too many or too-lengthy quotations for an encyclopedic entry. (May 2015)|
Back of an elderly woman with neurofibromatosis
|Classification and external resources|
Neurofibromatosis (NF) refers to a number of inherited conditions that are clinically and genetically distinct and carry a high risk of tumor formation, particularly in the brain. Neurofibromatosis is an autosomal dominant disorder, which means only one copy of the affected gene is needed for the disorder to develop. Therefore, if only one parent has neurofibromatosis, his or her children have a 50% chance of developing the condition as well (it is rarely the case that one person has the mutated gene twice, which would imply a 100% chance of his or her children developing NF). The severity in affected individuals can vary; this may be due to variable expressivity. Approximately half of cases are due to de novo mutations and no other affected family members are seen. It affects males and females equally. In addition, some individuals may have mosaic NF, in which some but not all cells of the body carry the mutation. The neurofibromatoses are as follows:
- Neurofibromatosis type I, in which the nerve tissue grows tumors (neurofibromas) that may be benign and may cause serious damage by compressing nerves and other tissues.
- Neurofibromatosis type II, in which bilateral acoustic neuromas (tumors of the vestibulocochlear nerve or cranial nerve 8 (CN VIII) also known as schwannoma) develop, often leading to hearing loss.
- Schwannomatosis, in which painful schwannomas develop on cranial, spinal and peripheral nerves.
Conditions which may be confused with NF-1 but which are not considered NF include:
The neurofibromatoses are considered as RASopathies and as members of the neurocutaneous syndromes (phakomatoses). In addition to the types of neurofibromatosis, the phakomatoses also include tuberous sclerosis, Sturge-Weber syndrome, and von Hippel-Lindau disease. This grouping is an artifact of an earlier time in medicine, before the distinct genetic basis of each of these diseases was understood.
Symptoms of NF1, which may be evident at birth and nearly always by the time the child is 10 years old, may include light brown spots on the skin ("cafe-au-lait" spots), two or more growths on the iris of the eye, a tumor on the optic nerve, a larger than normal head circumference, and abnormal development of the spine, a skull bone, or the tibia.
NF2 is less common and is characterized by slow-growing tumors on the eighth cranial nerves. The tumors cause pressure damage to neighboring nerves. [Diagnostic signs include] eighth nerve tumors, cataracts at an early age or changes in the retina that may affect vision, other nervous system tumors and similar signs and symptoms in a parent, sibling, or child.
The distinctive feature of schwannomatosis is the development of multiple schwannomas (tumors made up of certain cells) everywhere in the body except on the vestibular branch of the 8th cranial nerve. The dominant symptom is pain, which develops as a schwannoma enlarges or compresses nerves or adjacent tissue. Some people may develop numbness, tingling, or weakness in the fingers and toes."
— National Institute of Neurological Disorders and Stroke
In most cases, symptoms of NF1 are mild, and individuals live normal and productive lives. In some cases, however, NF1 can be severely debilitating and may cause cosmetic and psychological issues. The course of 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.
Recently, non-profit and charitable organizations have started to bring awareness and education about Neurofibromatoses to mainstream media in order to better connect those afflicted with helpful resources to lead more productive and satisfying lives. Personalities with the condition, such as Reggie Bibbs, are becoming notable public figures around which others can rally to gain motivation and support.
|Wikinews has related news: Interview with Reggie Bibbs on his life with neurofibromatosis|
- Ferner, Rosalie E., Susan M. Huson, and D. Gareth R. Evans. Neurofibromatoses in clinical practice. Springer, 2011.
- Conrad Fischer, Farshad Bagheri, Rajpal Manchandani, Richard Pinsker, Sudheer Chauhan, Parenkumar Patel, Mohammad Maruf, Dhaval Satani, Kaushik Doshi, Ayaz Alwani, Naveen Pathak, Craigh Thurm, Mohammad Babury, Mahendra C. Patel, Arthur Shalanov, Samir Sarkar, Sabiha Raouf, Jebun Nahar, Prakashkumar Patel (2010). Master the Board USMLE Step 2 CK. KAPLAN Medical. p. 287. ISBN 978-1-60714-653-7.
- "NINDS Neurofibromatosis Information Page". 23 February 2015. Retrieved 2015-04-21.
- "About the Foundation « Just Ask! Foundation". Justaskfoundation.org. Retrieved 2014-04-17.
- Wikinews:Interview with Reggie Bibbs on his life with neurofibromatosis
- Children's Tumor Foundation
- National Institute of Neurological Disorders and Stroke - information on Neurofibromatosis
- Neurofibromatosis Type 1
- A comprehensive list of current NF research studies, maintained by the St. Louis Children's Hospital