The neurofibromatosis type 2 gene is found on chromosome 22. It codes for a protein called merlin, which is a tumour suppressor protein particularly important in Schwann cells. Mutations in this gene lead to the development of schwannomas (benign nerve sheath tumours of the Schwann cells). Inheritance is autosomal dominant.
Neurofibromatosis type 2 is most associated with acoustic neuromas. These are tumours of the auditory nerve innervating the inner ear. Symptoms of an acoustic neuroma are:
Schwannomas can also develop in the brain and spinal cord with symptoms based on the location of the lesion.
Surgery can be used to resect tumours although there is a risk or permanent nerve damage.
TOM TIP: Bilateral acoustic neuromas almost certainly indicate neurofibromatosis type 2. This is a popular association in exams so worth remembering.