If someone develops symptoms of neurofibromatosis type 2 (NF2), a number of tests can be used to look for signs of the condition.
A family history of NF2 will also be taken into account when diagnosing the condition.
Some of the tests commonly used to check for signs of NF2 are described below.
A magnetic resonance imaging (MRI) scan uses strong magnetic fields and radio waves to produce detailed scans of the body’s soft tissue. It can be used to check for the presence of non-cancerous (benign) tumours inside the nerve tissue next to your ears, as well as your brain and spinal cord.
Hearing and eye tests
A number of different hearing tests can be used to find out whether your hearing has become impaired.
Eyes tests are often used to check for cataracts (cloudy patches at the front of the eye), which are common in NF2.
A blood test can be used to check your DNA for the NF2 mutation. However, this test only correctly identifies the mutation in about two-thirds of cases, so a negative result doesn't necessarily mean you don't have NF2.
If you or your partner has NF2, there's a chance you could pass it on to any children you have.
You may choose to have treatment to ensure that your children don't develop the condition, or you may wish to have tests during pregnancy to check if your child is affected.
Pre-implantation genetic diagnosis (PGD)
A type of in vitro fertilisation (IVF) treatment called pre-implantation genetic diagnosis (PGD) can be used to help ensure a pregnancy is unaffected by NF2.
In this procedure, several of the woman’s eggs are fertilised by the man’s sperm outside the body to produce embryos. The embryos can then be tested for the NF2 mutation, and one or two healthy embryos will be transferred into the womb.
You may qualify for funding for PGD on the NHS or you may need to consider paying for this privately. A course of PGD can cost between £6,000 and £10,000, and there's no guarantee that one course of treatment will lead to a successful pregnancy.
Tests during pregnancy
The most commonly used tests to check an embryo for the genetic mutation that causes NF2 include:
- chorionic villus sampling (CVS) – where a sample of cells from the placenta are removed and tested, usually between weeks 11 and 14 of pregnancy
- amniocentesis – where a sample of amniotic fluid is removed and tested, usually during weeks 15 to 20 of pregnancy
If you wish to have these tests during pregnancy, you'll be referred to a genetic counsellor to discuss the implications of the test result.
If tests show that your child will develop NF2, the genetic counsellor will support you through the testing process and help you decide how you want to proceed with the pregnancy.
Read more about genetic testing and counselling.