NF2-associated Schwannomatosis can be clinically diagnosed based on the following criteria:

• Bilateral vestibular schwannomas (VS)
  or
  a positive family history of NF2 (first-degree relatives= parents, siblings, children)
  plus
• Unilateral VSy
  or
  2 of the following: Meningioma/glioma/neurofibroma/swannoma/juvenile cataracts

Tinnitus (ringing in the ears) and increasing hearing loss in young adulthood are often the first symptoms that lead to a visit to the doctor. Balance problems, unsteady gait, headaches, numbness, or even paralysis of a facial nerve are also described.

Around 30% of patients develop symptoms in late childhood. At this age, initial symptoms are more often caused by benign tumors of the meninges (so-called meningiomas). Furthermore, damage to a nerve caused by schwannomas can lead to pain or loss of function. Sometimes, visual impairment caused by juvenile cataracts is the first sign that leads to a diagnosis.

The clinical signs are highly variable and subtle, with the first symptoms usually only appearing in young adulthood. Typical findings are listed below:

• Skin tumors are found in just over two-thirds of all patients. These are predominantly schwannomas, although neurofibromas are also rarely reported. These tumors present themselves in three forms:

• • Plaque-like schwannomas within the skin, slightly raised, pigmented (more color), and increasingly hairy
  • Nodular tumors under the skin, which may appear as a spindle-shaped, rough swelling
  • Neurofibromas that are located directly in the skin

• The irregularly bordered café-au-lait stains (CALF) typical of NF1 are also found more frequently in NF2 than in healthy people but are far less pronounced than in NF1.
• Schwannomas, neurofibromas, meningiomas, and gliomas are benign tumors originating from cells surrounding, protecting, insulating, and nourishing the nerve, the so-called nerve sheaths.
• Juvenile subcapsular lens opacity (cataract) is a particular form of lens opacity that occurs in adolescence and can lead to a deterioration in vision.

NF2-associated Schwannomatosis is a genetic disease caused by a mutation, a change in the genetic material—the affected gene codes for a merlin protein, sometimes known as schwannomin. Merlin is mainly found in nerve tissue and acts as a tumor suppressor, i.e., it counteracts tumor development by inhibiting growth.

NF2-associated Schwannomatosis occurs in about 1 in 25-33:000 people. Just over a third of the diseases are inherited and passed on from parents to their children; the inheritance is autosomal dominant. This means the probability of passing on the disease (inheritance) is 50%. Slightly less than 2/3 of diseases are due to a spontaneous or new mutation, known as a de novo mutation. This means that the genetic change has arisen in the patient themselves.

Genetic testing is possible and is recommended to confirm the diagnosis for all individuals with a clinical diagnosis and all patients with tumors typical of NF2-associated Schwannomatosis (meningiomas, schwannomas). Genetic testing of potentially affected but non-symptomatic family members is recommended from 10-12.

If you have the impression that your child’s hearing is worse in one or both ears if he or she complains of increased headaches, morning sickness, becomes tired quickly after reading, or complains of numbness or paralysis in the face (asymmetry of facial features), or if you notice a dropped hand or foot drop, please make an appointment with your eye specialist, pediatrician or in an NF special outpatient clinic.

• Link to the website of the “Children’s Tumor Foundation”
• Link to German website of Neurofibromatosis Association

Patients can also register for the KPS register at any time or have this done by the doctors in charge.

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