Acoustic or central NF is an autosomal dominant form characterized by an almost 100 percent incidence of bilateral acoustic neuromas.
Few neurofibromas are present.
Lisch nodules are absent. Variant NF is an autosomal dominant form in which cutaneous, acoustic and other CNS lesions may be present but that does not fit well into other groupings. There have been 15 reported cases. A post zygotic mutation restricted to somatic cells has been assumed to be responsible for most cases. However, in two cases of segmental disease, genetic transmission of the generalized disease has been reported.