Occurs in 17% of congenital, 25% of late latent, 39% of symptomatic neurosyphilis.
In those with congenital syphilis, hearing loss is sudden in early childhood. Is usually sudden, bilateral, and looks like Menieres.
Other manifestations: Nasal cartilage damage, frontal bossing, saber shins, Hutchinson teeth, short stature, cloudy corneas.
Café-au-lait spots, multiple fibromas. Tumors can be in the CNS, peripheral nerves, and viscera.
Mental retardation, blindness, and SNHL can result from CNS tumors.
NF1 is more common. Many café-au-lait spots, cutaneous neurofibromas, plexiform neuromas, pseudoarthroses, lisch nodules of the iris, optic gliomas. Abnormal NF1 gene on chromosome 17.
NF2: Bilateral acoustics, café-au-lait spots, subcapsular cataracts. Bilateral are present in 95%. Deletions in the NF2 gene on chromosome 22.
Both are autosomal dominant but with variable expressivity.