Monday, January 31, 2005

Neurofibramatosis Type 2 (NF2) – A Short Note

What is NF2
NF2 is a rare genetic condition with a prevalence of 1 in 40,000 people. [ 1 ]

Technical Stuff
NF2 is caused by a defect in the NF2 gene on chromosome 22. This gene is responsible for producing a protein call merlin or schwannomin.

Merlin is expressed in nerve cells, specifically called schwann cells. Schwann cells wrap around the axons of nerve cells. Merlin is responsible for control of growth of these schwann cells. Under the condition of NF2, Merlin is absent or mutated. So, merlin will not be effective in controlling the growth of schwann cells, which results in tumours. Merlin is also required in other cells for
controlled growth, absence of Merlin thus means, potential for tumours in other parts of the body [ 2 ]

How does one get NF2? [ 3 ]
Through one of the following ways:
1) Gene mutation
2) Hereditary: There is a 50% probability of a child inheriting NF2 from a parent who has an NF2 gene, either in dominant or carrier form

Effects of NF2
One of the typical effects of NF2 is "Acoustic Neuromas" (AN) or "Schwannomas"[ 4 ], which is the uncontrolled growth of Schwann cells of the seventh and eighth cranial nerves (CN VII and VIII) (typically both right and left sides of the brain). CN VIII is responsible for transmission of sound-induced nerve impulses between the inner ear and the brainstem, and transmission of balance information. CN VII is the facial nerve responsible for the movement of half the face on the same side as the nerve Symptoms produced by AN include:
  • Hearing loss
  • Ringing in the ear (tinnitus)
  • Imbalance
  • Dizziness (vertigo)
  • Facial weakness
  • Facial numbness or pain
  • Discomfort (feeling of fullness/pressure) in or around the ear
Tumours in other places in brain and the body (spinal cord) are also possible. Typically, NF2 tumours are benign tumours.

Treatment options [ 5 ]
In the words of a neurosurgeon, "NF2 and its forme fruste are indeed a challenging problem for any neurosurgeon and it is also an extremely difficult proposition of balancing the conservative versus operative management of different problems for any patient. The best approach is to deal with the lesions that are causing problems that hamper normal living. Although the problems may never be sorted out completely, a balance has to be maintained between treatment (which may be aggressive at times) and quality of life and productivity."

Options available today:
1. Open Surgical Treatment
2. Variety of Radiatition treatments: Stereotactic radiation therapy/surgery – SRT/SRS,
Fractionated radiosurgery - FRS, cyberknife surgery, gamma knife surgery [ 6 ]

Meanwhile, research continues to offer genetic treatment for NF2 [ 7 ]. Technology also keeps advancing in general surgery and radiation treatments. [ 8 ]

Disclaimer: I do not claim ownership of this note. This note is a short introduction about NF2 with pieces taken from various sources and sewn together for a quick overview. I have acknowledged sources I have used.

References
[ 1 ] What is NF http://www.nf.org/what_is_nf
[ 2 ] NF2 Video http://www.ygyh.org/nf/cause.htm
[ 3 ] Genetics of NF2 http://www.nf.org/what_is_nf/genetics_nf2.htm
[ 4 ] About Acoustic Neuroma http://www.cksociety.org/PatientInfo/MedicalConditions/acoustic_neuroma.asp
[ 5 ] Managing NF2 http://www.nf.org/what_is_nf/managing_nf2.htm
[ 6 ] http://www.cksociety.org/PatientInfo/MedicalConditions/acoustic_neuroma.asp#stereotactic
[ 7 ] RAS treatments for NF http://www.nf2crew.org/maruta.htm
[ 8 ] Recent Milestone Research Papers
http://www.nf.org/recent_papers/milestone_papers_post1990.htm
[ 9 ] NF2 Support Group on the web http://www.nf2crew.org
[ 10 ] Several Good Links http://www.nf2crew.org/links.php

2 Comments:

Anonymous Anonymous said...

The first on the Crew to start a blog! Thanks for sharing, Girish. Warm Regards, Jamie from the NF2 Crew

9:21 AM  
Anonymous Anonymous said...

Girish - Very nice. Love the poem, too!
Poetgirl on Crew!

12:23 PM  

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