Phakomatosis

Phakomatoses (or neuro-oculo-cutaneous syndromes, neurocutaneous disorders) are multisystem disorders that have characteristic central nervous system, ocular, and cutaneous lesions of variable severity. The skin and the brain have a common ectodermal origin, so there are many genetic and acquired diseases that affect both tissues. However, in some conditions, such as von Hippel-Lindau disease, ectodermal presentation is minimal.