NF2-related schwannomatosis
NF2-related schwannomatosis (ORPHA:637, previously called Neurofibromatosis type 2) is a disorder characterized by the development of noncancerous tumours along the nerves called schwannomas, which nearly always occur on the hearing and balance nerves (vestibular schwannomas-VS). NF2-related schwannomatosis is present in an estimated 1 in 30,000 new-borns. Most sufferers develop symptoms after the age of 10 years such as VS on both sides leading to balance problems and eventually total deafness. Schwannomas on other nerves in the head and spine and elsewhere in the body can cause loss of muscle function and sensation with many affected people ending up in a wheelchair. The second commonest tumour is a noncancerous tumour on the lining of the brain and spinal cord called a meningioma. This too can lead to loss of normal function including headaches and seizures. Finally a tumour within the spinal cord called an ependymoma affects around 20-40% of people but are usually non progressive. NF2-related schwannomatosis is a life spoiling life limiting condition. Every individual with a disease causing variant in the NF2 gene will develop symptoms sometime in life.
NF2-related schwannomatosis is an inherited genetic condition caused by a fault in one copy of the NF2 gene on chromosome 22.
NF2-related schwannomatosis is inherited from an affected parent in about 40% of cases. In the remainder the NF2 gene change starts with that person. This is either in all their cells (65-70%) indicating that the change was present in the egg or sperm that made their first cell at conception or in only some of their cells indicating the gene fault occurred during development as an embryo (called mosaicism). Mosaic NF2-related schwannomatosis is milder as not all cells are affected and the likelihood of passing the disease down to children is reduced from the usual 50%. Identifying the underlying gene fault in individuals with suspected mosaicism is also helpful in assessing the potential severity of the condition starting with testing of tumour in isolated cases in combination with if possible.
Screening in NF2-related schwannomatosis can start with testing for the family gene fault of unaffected relatives before symptoms appeared. Thereafter screening is generally based on the current problems but in adults will usually mean at least an annual head MRI scan and 3 yearly spinal MRI. Treatments include surgical removal of tumours, drug treatments with bevacizumab for rapidly growing schwannomas and in selected cases targeted radiation treatments (not in childhood).
GeneReviews® - NF2-related schwannomatosis
Orphanet: NF2-related schwannomatosis
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Thematic Group 1: Schwannomatosis and neurofibromatosis
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* ERN GENTURIS uses AGREE II as a tool for the endorsement of guidelines. The quality of the guideline is evaluated through assessing the rigor and transparency of the guideline development process. The content of the guideline is not evaluated, although selection of the guideline for endorsement includes expert opinion on the usefulness of the content of the guideline.
ERN GENTURIS webinars - Thematic group 1: Neurofibromatosis
ERN GENTURIS webinars - General
A list of healthcare providers with expertise in Thematic Group 1: schwannomatosis and neurofibromatosis can be found here.
A non-exhaustive list of patient associations for genetic tumour risk syndromes in EU member states can be found here.