At least 8 different clinical phenotypes of neurofibromatosis have been identified linked to at least two genetic disorders.
Clinical manifestations increase over time.
Neurological problems as well as the development of malignancy may supervene. Thus, the presenting signs and symptoms may vary widely. These descriptions are not especially accurate, as NF-1 often has central features. Segmental NF may be related to mosaicism or segmental hyperexpression of the condition. Loss of heterozygosity may create the clinical impression of segmental lesions.