Genetic counselling

When a diagnosis of neurofibromatosis type 1 is made, a family history of the condition should be sought. Sharing of information within the family should be encouraged so that first-degree relatives can be screened (by skin and slit lamp examination) to determine whether or not they have neurofibromatosis type 1. Affected families should be seen by a genetic counsellor or a clinical geneticist, to discuss recurrence risk and reproductive options.

Most women with neurofibromatosis type 1 have normal pregnancies. The number and size of their cutaneous neurofibromas may increase during pregnancy. When one parent has neurofibromatosis type 1, each pregnancy has a 50% risk of an affected child. The disorder does not ‘run true’ within the family, so it is not possible to predict severity (ie a mildly affected parent can have a severely affected child, or vice versa).

Identifying the NF1 gene mutation after the clinical diagnosis can be useful for reproductive planning.