Neurofibromatosis type 1 (NF1) is usually diagnosed by checking for the characteristic symptoms of the condition, such as coffee-coloured skin patches (café au lait spots) and bumps on or under the skin (neurofibromas).
A confident diagnosis can usually be made if two or more of the following symptoms are present:
It is usually easy to diagnose NF1 in adults, but it can take several years for all the symptoms to develop in children. As a result, it's not always possible to make a firm diagnosis before a child is five years old.
Further tests may be recommended to assess whether your child has developed additional symptoms or secondary conditions that are known to be associated with NF1. Some of these tests are described below:
If there is uncertainty about the diagnosis, your child can be tested to see whether they have the NF1 mutated gene. This involves extracting DNA from a sample of their blood and analysing it to check whether they have inherited the faulty gene.
However, the test is not always completely reliable. Around 5% of children who test negative for the mutated gene still develop NF1.
Couples with a family history of NF1 who are thinking of having a baby can be referred to a genetics specialist for advice.
A genetic counsellor can help couples work through the decision-making process and explain possible alternatives, such as adoption or artificial insemination (where sperm taken from the man is inserted directly into his partner’s womb).
However, NF1 is unpredictable. How mild or severe a parent's symptoms are will not determine how the child will be affected or what complications they may have.
Last updated : 2011-09-11 by NHS Choices © Crown Copyright 2009