Table 1. Major features of the neurofibromatosis and diagnostic criteria.
| NF1 | NF2 | |
|---|---|---|
| Incidence* | 1:2600 – 1:4500 | 1:33,000 |
| Prevalence* | 1:2700 | 1:56,000 |
| Inheritance | Autosomal dominant, complete penetrance | Autosomal dominant, complete penetrance |
| Features | Café-au-lait macules, skinfold freckling, neurofibromas, plexiform neurofibromas, malignant peripheral nerve sheath tumors, optic glioma, skeletal dysplasia, learning disability |
Vestibular schwannomas, other cranial and peripheral nerve schwannomas, meningiomas, ependymomas, cataracts |
| Gene/Protein |
NF1 – chromosome 17/neurofibromin – GTPase activating protein |
NF2 – chromosome 22/merlin – cytoskeletal protein |
| Diagnostic criteria | At least two of: > 6 café-au-lait macules (> 5 mm prepubertal, > 15 postpubertal) |
Definite diagnosis: bilateral VS, or family history of NF2 and unilateral VS or any two of: meningioma, glioma, neurofibroma, schwannoma, posterior subcapsular cataract |
| 2 or more neurofibromas or 1 plexiform neurofibroma |
||
| iris Lisch nodules | or | |
| skinfold freckling optic glioma characteristic skeletal dysplasia (long bone or sphenoid) |
unilateral VS and any two of: meningioma, glioma, neurofibroma, schwannoma, posterior subcapsular cataract or |
|
| affected first-degree relative | multiple meningiomas plus unilateral VS or any two of: glioma, neurofibroma, schwannoma, posterior subcapsular cataract |