Diagnostic criteria for neurofibromatosis type 1 (NF1) established by the National Institutes of Health (NIH) consensus development conference1
| Individual is affected with NF–1 if two or more of the following are met |
| • Six or more café au lait macules over 5 mm in greatest diameter in prepubertal individuals and over 15 mm in greatest diameter in postpubertal individuals |
| • Two or more neurofibromas of any type or one plexiform neurofibroma |
| • Freckling in the axillary or inguinal regions |
| • Optic glioma |
| • Two or more Lisch nodules (iris hamartomas) |
| • A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex, with or without pseudoarthrosis |
| • A first degree relative with NF–1 by the above criteria (NIH 1988) |