neurofibromatosis (NF1)

    
      Re: neurofibromatosis (NF1)
    


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Posted by CCF Neuro ND on June 19, 1997 at 15:43:52:

In Reply to: neurofibromatosis (NF1) posted by Ole Kirkelund on June 10, 1997 at 10:39:27:

: What are the possibilities of identifying the affected gene (on chromosome 17)
  - in cases of new mutation?
  - in cases of prior history of NF in the family?
  and:
  approximately how many (%) of NF patients have "Lisch nodules"?
  (as far as I know it is more than 90% - and only NF patients have Lisch nodules)
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Hello Ole,
Neurofibromatosis 1 is a common genetic disorder with a prevalence of approximately one in 3000 live births.  The pathogenesis (what causes the disease) is not known.  Molecular genetics have identified the NF 1 gene on chromosome 17 and various specific mutations that contribute to the development of the disease.   The mutation probably results in a loss of function of the NF 1 gene product which is a protein that has been named neurofibromin.  It is thought that it attenuate the aggressive growth of neuroectodermal tissues (cells from both the nervous system as well as skin).  It is been found to act as a tumor suppresser gene.  NF 1 has an autosomal dominant inheritance pattern with a  high degree of penetrance.  Meaning that there is a good chance of inheriting the gene for NF 1 in the familial form of the disease.  
The genetic test for NF 1 is not fool proof.  For all cases there is a about 70% chance of finding the gene mutation.  This is because the mutation can vary in different families and the mutation can be small making it difficult to detect.  The diagnosis of NF 1, for that reason, is made clinically and not solely by genetic testing.
If you or a someone you know are interested in further information I would suggest that you speak to a genetic counselor.  If you are interested in coming to the Cleveland Clinic for a second opinion on the diagnosis or treatment of NF 1, I would suggest you get in touch with Dr Bruce Cohen a neurologist who has a special interest in neurofibramtosis.