Neurofibromatosis types 1 & 2: Symptoms, diagnosis and treatment
Neurofibromatosis is the term for a group of genetic conditions in which tumours grow along a person's nerves.
Neurofibromatosis type 1 (NF1) symptoms
This is the most common type of neurofibromatosis and affects around 1 in 3,000 babies in the UK.
Not everyone will get all the symptoms, and some symptoms are more common than others. Symptoms of neurofibromatosis type 1 include:
- Café-au-lait spots - patches of tan coloured or light brown skin
- Freckles in unusual locations, including the groin, armpits and beneath breasts in women
- Soft lumps under the skin, called neurofibromas
- Learning difficulties
- ADHD (attention deficit hyperactivity disorder)
Eye problems, optic pathway glioma (OPG)
- High blood pressure
- Scoliosis (curved spine)
- Larger than usual head
Weighing less than normal
- Smaller size than normal
Pseudarthrosis - bone development problem, fractures
- Brain tumours
Malignant peripheral nerve sheath tumour (MPNST) causing nerves and neurofibromas to harden
Additional neurofibromas developing during pregnancy hormone changes.
Neurofibromatosis type 1 causes
Neurofibromatosis type 1 is caused by a mutation in the NF1 gene on chromosome 17 that affects nerve tissue growth.
With NF1 the body doesn’t get the usual messages to stop growing nerve tissue, so uncontrolled growth happens.
NF1 can be inherited from one or both parents. However, the severity of symptoms does not always match those of a parent.
In other cases, the gene mutation happens irrespective of inherited genes, called spontaneous mutation.
A person whose NF1 developed spontaneously can pass it on to their children.
Neurofibromatosis type 1 diagnosis
Neurofibromatosis type 1 diagnosis will begin with assessment of the child's symptoms and family history of the condition. However, diagnosis may be harder with younger children until they develop more and further symptoms emerge.
Tests may be arranged to confirm the diagnosis, including:
Neurofibromatosis type 1 and pregnancy
If parents are concerned about passing on NF1 genes to a child, a referral to a genetic specialist or counsellor before planning a pregnancy can be arranged.
They will discuss the risks and options.
One option is using an IVF technique where embryos are tested for NF1 before being implanted so that only those not affected are used in the procedure.
During pregnancy, tests can be done to look for signs of NF1, but cannot predict how severe symptoms will be. These tests include:
Neurofibromatosis type 1 treatment
Neurofibromatosis type 1 cannot be cured, but a specialist team can help monitor the condition and advise on management of symptoms and care needs.
If the look of café-au-lait spots are causing distress, special camouflage make-up is available.
If neurofibromas are causing problems or concerns, removal by plastic surgery is possible for some of these lumps.
As well as physical symptoms, special educational needs and behavioural problems will need specialist help and support from the child's school.