Neurofibromatosis type 1

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On our other pages you will find information on the following topics:

  • Symptoms of neurofibromatosis type 1
  • Life expectancy and therapy for neurofibromatosis type 1
  • Neurofibromatosis type 2
  • Symptoms of neurofibromatosis type 2

Classification

  • Neurofibromatosis type 1
  • Neurofibromatosis type 2

Synonyms in a broader sense

  • Recklinghausen's disease
  • Recklinghausen's disease
  • NF1
  • peripheral neurofibromatosis

Definition and introduction

The Neurofibromatosis type 1 is a genetic disease, Which autosomal dominant is inherited.
A genetic mutation in the "Neurofibromin gene" on Chromosome 17 leads to changes, especially in:

  • Nervous system
  • skin
    and
  • skeleton.

It is a monogenic disease with an age-dependent manifestation (penetrance).
The degree of expression (expressivity) is also variable.
In 50% of the cases it is a new mutation.

diagnosis

By detecting the mutated gene on chromosome 17 using laboranalytical methods the diagnosis can be saved. However, these processes are complex and expensive, so that they are usually not used.

The diagnosis is therefore usually made clinically using the methods described above Main criteria, at least two of which must apply.
Of these main criteria, two stand out in particular. Those specific for neurofibromatosis Neurofibromas and which are often conspicuous as early as infancy Café-au-lait spots.

Epidemiology / frequency

The incidence, which means frequency in the population, is 1:3500 Newborn.
Men and Women are equal often affected.
50% of the cases are new mutations.

Cause (ethiology)

The mutation of the neurofibromin gene on chromosome 17 is a new mutation in 50% of cases.
It can lead to:

  • Point mutations (exchange of bases in the DNA = change in the genetic code)
  • Deletions (loss of DNA)
  • Duplications (duplication of DNA parts)
  • Insertions (twisting of DNA parts)
  • Splice mutations

etc. come.

Neurofibromin is a human protein that is located in the cells and is responsible for a so-called RAS-GAP signal cascade with other proteins.
As a negative regulator, together with the other proteins, it ensures a balance between growth and differentiation (specialization / function) of cells.
If this neurofibromin is missing due to a mutation or if there is a deficiency, this balance is canceled and the focus falls on growth.
Put simply, there is a lot of neurofibromin of poor quality.

Further information on neurocutaneous syndromes can be found here: Neurocutaneous Syndrome

Main criteria neurofibromatosis type 1

Neurofibromatosis exists when at least two of the following main criteria are present:

  1. Six or more café-au-lait spots
  2. axillary (in the armpit) and / or inguinal (in the groin) mottling
  3. at least two neurofibromas or at least one plexiform neurofibroma
  4. Optic glioma
  5. at least two Lisch nodules of the iris
  6. Bone deformities (bone deformation), especially of the sphenoid bone (Os sphenoidale = part of the skull bone)
  7. First-degree relative with neurofibromatosis type 1

Desire for children

In principle, nothing stands in the way of the offspring of NF1 (neurofibromatosis type 1) sufferers.
Because the NF1 autosomal dominant is inherited, there is a risk of having a sick child 50%if one parent is involved.
Modern technical and analytical processes make it possible to obtain certainty at an early stage.
If the child is also ill, the parent's symptoms cannot be used to determine the course of the child's disease.

Pregnant women with neurofibromatosis often report having new neurofibromas during the pregnancy form or pre-existing neurofibromas begin to grow.
Not infrequent is a Caesarean section necessary if the pelvic region of the pregnant woman is affected by neurofibromas. As a rule, however, the pregnancy proceeds without complications.