Comparison of Neurofibromatosis Type 1 and Proteus Syndrome
| Neurofibromatosis Type 1 | Proteus Syndrome | |
|---|---|---|
| Prevalence | Frequent (1 in 3000 to 1 in 4000 live births worldwide) | Extremely rare (<1 in 1,000,000 live births worldwide) |
| Equally prevalent in men and women | Two men for every woman | |
| Gene | NF1, chromosome 17 | Unknown |
| Transmission | 50% hereditary (autosomal dominant) | Sporadic |
| 50% sporadic (de novo mutation) | Postzygotic somatic mutation (embryonic lethal in nonmosaic form) | |
| Diagnostic criteria | ||
| General | Café-au-lait spots | Mosaic distribution of lesions |
| Neurofibromas | Sporadic occurrence | |
| Axillary or inguinal freckling | Progressive course | |
| Optic gliomas | ||
| Lisch nodules | ||
| Characteristic osseous lesion (sphenoid dysplasia, thinning of long bone cortex with or without pseudoarthrosis) | ||
| First-degree relative with neurofibromatosis type 1 | ||
| Other | Cerebriform connective tissue nevus | |
| Linear epidermal nevus | ||
| Asymmetric, disproportionate overgrowth | ||
| Specific tumors before second decade | ||
| Lipomas or focal atrophy of adipose tissue | ||
| Capillary, venous, or lymphatic malformation | ||
| Facial features including dolichocephaly, a long face, down-slanting palpebrae, ptosis, depressed nasal bridge, anteverted nares, and open-mouth position while at rest |