When does neurofibromatosis symptoms start to develop?

By age 5: Over 99% of neurofibromatosis (also called von recklinghausen's disease) victims will show signs of the disease by age 5. So if you're older than that you almost certainly don't have it!

It varies: Signs of neurofibromatosis type 1 (nf1) can appear before birth or may not be apparent until well into adulthood. Cafe-au-lait (that's french for coffee with milk) spots are often the first thing to be noticed in children; usually more than 5 spots that are bigger than 1/2 cm. Nf2 is a completely different condition with hearing loss or cataract often the first symptom in the late teens/early 20s.

Sometimes at birth: Several signs of nf, the main one six or more flat brown spots over 5 mm in greatest diameter in children and over 15 mm in greatest diameter in post-pubertal individuals, two or more soft nodules or neurofibromas or 1 plexiform neurofibroma, freckling in the axillary or groin regions, tumors of optic nerve, gliomas, bony abnormality such as scoliosis, bone overgrowth or congenital fracture.