NF1 is a condition that follows an Autosomal dominant inheritance pattern and affects nerve cell tissue, causing the growth of small tumours throughout the nervous system.
Symptoms usually appear during childhood and may become more pronounced during puberty, pregnancy and when hormonal changes take place. The severity of the condition can vary greatly, even within a family.
NF1 may be inherited, but up to 50% of cases are caused by a de novo mutation; therefore, family history may not be present.2
The diagnosis of NF1 is made on the basis of presence of specific physical findings. Characteristic features of NF1 include:
- multiple café-au-lait spots
- inguinal or axillary freckling
- multiple neurofibromas.
Additional features can include:1,2
- optic glioma
- Lisch nodules (iris hamartomas)
- osseous lesions (eg sphenoid dysplasia)
- increased risk of various cancers
- precocious puberty or delayed sexual development
- specific learning disabilities
- short stature
- renal artery stenosis.