A short review of Neurofibromatosis

Neurofibromatosis is a group of neurocutaneous disorders. Which means, neurofibromatosis mainly affects the skin and nervous system.

Neurofibromatosis is divided into two different types.

Neurofibromatosis type 1 and Neurofibromatosis type 2.

There are few things common between the two.

Both are autosomal dominant diseases
and both occurs due to loss of function mutation.

Neurofibromatosis type 2 gene is located on a region on long arm of chromosome 22.

This region is band 12.

Band 12 codes for neurofibromin 2 gene, which in turn codes for membrane protein, merlin.

Just like neurofibromin, merlin too is a tumour suppressor protein.

Merlin inhibits PI3 kinase pathway and mTOR pathway. Thus eventually stopping cell proliferation.

Out of all the cases of Neurofibromatosis, 97% of them are Neurofibromatosis type1

And only 3% make up Neurofibromatosis type 2.

50% of Neurofibromatosis type 1 are sporadic in nature and the other 50% are inherited.

One thing we must know, is that, Neurofibromatosis doesn’t show any gender or racial predilection.

Neurofibromas are benign tumours which are made up of variety of cells like, axons, peri neural cells, Schwann cells, mast cells and collagenous Matrix.


Neurofibromatosis have both cutaneous and non cutaneous manifestations.

Cutaneous manifestation of Neurofibromatosis includes

Cafe au lait spots. These are brown coloured macules with smooth borders.

Freckling in axillary region. It is also called Crowe sign.

Dermal tumours, which can be dome like or pedunculated.

And finally plexiform neurofibromas. Plexiform neurofibromas can feel like bag of worm.

The non cutaneous manifestation of Neurofibromatosis are scoliosis, lisch nodules, optic nerve glioma and even leukaemia.

The spectrum also includes some neuropsychiatric disorders like ADHD and learning difficulties.

Neurofibromatosis 2 can present with vestibular schwannoma or acoustic neuroma. It can be present bilaterally or unilaterally.

These can lead to the symptoms of tinnitus, hearing difficulties and problem balancing.

Neurofibromatosis type 2 is also associated to meningiomas.


Coming to treatment:

Neurofibromatosis 2 can present with vestibular schwannoma or acoustic neuroma. It can be present bilaterally or unilaterally.

These can lead to the symptoms of tinnitus, hearing difficulties and problem balancing.

Neurofibromatosis type 2 is also associated to meningiomas.

For Neurofibromatosis, many investigations like MRI, audiological assessment and ophthalmological opinion are required.

Surgery however remains the first line of therapy. Surgery is especially indicated if acoustic neuroma is seen compressing the brainstem.

Lastly, Bevacizumab, a VEGF inhibitor, which is a monoclonal antibody can be used to treat Neurofibromatosis type 2 medically.

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  Neurofibromatosis Type 2