Clinical features
- NF1 is characterised by the development of multiple café-au-lait spots, inguinal/axillary freckling and multiple neurofibromas.
- Symptoms usually appear during childhood and may become more pronounced during puberty, pregnancy, or when hormonal changes take place.
- Range and severity of symptoms can vary greatly among affected individuals even between family members.
- Rate of progression is not predictable.
- Diagnosed when two of the following clinical features are present:
- Six or more café-au-lait spots, >0.5cm diameter before puberty, or >1.5cm in adults
- Two or more neurofibromas of any type or one plexiform neurofibroma
- Freckling under the arms or in the groin area
- Benign tumour of the optic nerve (glioma)
- Two or more Lisch nodules (iris hamartomas)
- A distinctive osseous lesion such as a sphenoid dysplasia or thinning of the long bone cortex with or without psuedoarthrosis
- A 1° relative (parent, sibling or offspring) with NF1 by the above criteria
- Additional but not diagnostic features:
- Precocious puberty or delayed sexual development may occur
- About 50% have specific learning disabilities in reading, spelling or mathematics
- Growth may be reduced
- Macrocephaly
- Scoliosis
- Hypertension
- Epilepsy
