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Neurofibromatosis

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Neurofibromatosis
SpecialtyMedical genetics, neurology Edit this on Wikidata

Neurofibromatosis is a genetically-transmitted disease in which nerve cells (Schwann cells) grow tumors (neurofibromas) that may be harmless or may cause serious damage by compressing nerves and other tissues. The tumors may cause bumps under the skin, colored spots, skeletal problems, pressure on spinal nerve roots, and other neurological problems. [1]

Neurofibromatosis is autosomal dominant, which means that it is autosomal (it affects males and females equally often) and dominant (you only need one copy of the affected gene to get the disorder). Therefore, if only one parent has neurofibromatosis, his or her children have a 50% chance of developing the condition as well. Disease severity in affected individuals, however, can vary (this is called incomplete penetrance). Moreover, in around half of cases there is no other affected family member because a new mutation has occurred.

Types

Diagnostic Criteria

Neurofibromatosis type 1

Neurofibromatosis type 1 - mutation of neurofibromin chromosome 17q11.2

plexiform neurofibroma
Patient with multiple small cutaneous neurofibromas and a 'café au lait spot' (bottom of photo, to the right of centre). A biopsy has been taken of one of the lesions

Neurofibromatosis type 2

Neurofibromatosis type 2 - mutation of merlin chromosome 22q12

Schwannomatosis

Schwannomatosis - gene involved has yet to be identified

  1. Multiple Schwannomas occur.
  2. The Schwannomas develop on cranial, spinal and peripheral nerves.
  3. Chronic pain, and sometimes numbness, tingling and weakness.
  4. About 1/3 of patients have segmental Schwannomatosis, which means that the Schwannomas are limited to a single part of the body, such as an arm, a leg or the spine.
  5. Unlike the other forms of NF, the Schwannomas do not develop on vestibular nerves, and as a result, no loss of hearing is associated with Schwannomatosis.
  6. Patients with Schwannomatosis do not have learning disabilities related to the disease.

Genetics and Hereditability

NF-1 and NF-2 may be inherited in an autosomal dominant fashion, as well as through random mutation.

Neurofibromatosis type 1 is due to mutation on chromosome 17q11.2 , the gene product being Neurofibromin ( a GTPase activating enzyme).[2]

Neurofibromatosis type 2 is due to mutation on chromosome 22q , the gene product is Merlin, a cytoskeletal protein.

Both NF1 and NF2 are autosomal dominant disorders, meaning that only one copy of the mutated gene need be inherited to pass the disorder. A child of a parent with NF1 or NF2 and an unaffected parent will have a 50% chance of inheriting the disorder.

Complicating the question of heritability is the distinction between genotype and phenotype, that is, between the genetics and the actual manifestation of the disorder. In the case of NF1, no clear links between genotype and phenotype have been found, and the severity and specific nature of the symptoms may vary widely among family members with the disorder.[3] In the case of NF2, however, manifestations are similar among family members; a strong genotype-phenotype correlation is believed to exist (ibid).

Both NF1 and NF2 can also appear to be spontaneous mutation, with no family history. These cases account for about one half of neurofibromatosis cases (ibid).

How NF Can Affect You

People with Neurofibromatosis can be affected in many different ways.

  • There is a high incidence of learning disabilities in people with NF. It is believed that at least 50% of people with NF have learning disabilities of some type.
  • The tumors that occur can grow anywhere a nerve is present. This means that:
    • They can grow in places that are very visible to people that a patient may encounter on the street.
    • The tumors can also grow in places that can cause other medical issues that may require them to be removed for the patient's safety.
  • Affected individuals may need multiple surgeries, depending on where the tumors are located.

Treatment

There is no cure for the disease itself. Instead, people with neurofibromatosis are followed by a team of specialists to manage symptoms or complications. Surgery may be needed when the tumors compress organs or other structures. Less than 10% people with neurofibromatosis develop cancerous growths; in these cases, chemotherapy can be tried.[4]

History

Neurofibromatosis was discovered in 1882 by the German pathologist Friedrich Daniel von Recklinghausen. He wrote on it and published it in Hämochromatose, Tageblatt der Naturforschenden Versammlung.[5]

Joseph Merrick, the Elephant Man, was once considered to have been afflicted with either elephantiasis or neurofibromatosis type I. However, it is now generally believed that Merrick suffered from the very rare Proteus syndrome. This however has given rise to the common misconception that Neurofibromatosis and "Elephant Man Disease" are one and the same.

Neurofibromatosis is considered a member 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.

Neurofibromatosis in Pop Culture

In the television series Dallas, the inherited neurofibromatosis of the Barnes family is a driving plot device, although the portrayal of the condition does leave something to be desired in terms of scientific fact.

The disease is also a pivotal plot element in the Icelandic film Mýrin (Jar City) and Tainted Blood, the novel on which it was based.

Gillian Anderson, who played Scully on the X-Files, is a spokesperson and helps in the raising of money for neurofibromatosis, because her brother suffers from the disease.

Notable Cases

In November 2006, there was an hour-long documentary on the British television network Channel 4 about Facing the World, an organization that helps children with severe facial disfigurements in developing countries. One of the children featured on the documentary was Arianto, an Indonesian boy who suffered from a severe form of neurofibroma resulting in hemifacial giganticism.

In January 2008, 32-year-old Huang Chuncai of China underwent a second operation to remove another 9.9 lb (4.5 kg) of tumor from his face. A previous operation removed 33 pounds (15 kg) from what was originally a 55.7 lb (23 kg) tumor. [6] [7]

In March 2008 the treatment of 30-year-old neurofibromatosis victim Pascal Coler of France ended after having received what his doctors call the world's first successful full face transplant.[8][9]

See also

Wikinews has related news:

References

  1. ^ http://www.merck.com/mmhe/sec06/ch088/ch088d.html Merck Manual Home Edition, "Neurofibromatosis"
  2. ^ Fauci, et al Harrison's Principle of Internal Medicine 16th Ed. p 2453
  3. ^ Korf, Bruce E. and Allan E. Rubenstein. 2005. Neurofibromatosis: A Handbook for Patients, Families, and Health Care Professionals.
  4. ^ Neurofibromatosis. JAMA patient page, Vol. 300 No. 3, July 16, 2008.
  5. ^ doctor/1174 at Who Named It?
  6. ^ "ABC News: 50-Pound Face Tumor: One Man's Nightmare". Retrieved 2008-01-23.
  7. ^ Radford, S. (2008-01-11). Chinese man has surgery for 10 kg face tumour. Retrieved on 2008-01-29 from http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2008/01/09/whuang109.xml.
  8. ^ Watt, Nick (2008-03-25). "World's First Full Face Transplant Hailed". abcnews.go.com. Retrieved 2008-03-25. {{cite web}}: Check date values in: |date= (help)CS1 maint: date and year (link)
  9. ^ Franklin, Katie (2008-03-25). "Man has first full-face transplant". telegraph.co.uk. Retrieved 2008-03-25. {{cite web}}: Check date values in: |date= (help)CS1 maint: date and year (link)
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