Table 1.

National Institutes of Health Diagnostic Criteria for Neurofibromatosis Type 1

Two or more of the following clinical features must be present:
Six or more café-au-lait macules (> 5 mm in greatest diameter in prepubertal individuals or > 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 iris hamartoma (Lisch nodules)
Distinctive bony lesion such as sphenoid dysplasia, or thinning of the long bone cortex with or without pseudoarthrosis
A first-degree relative (parent, sibling, or offspring) with NF 1 based on the above criteria.