This is a multisystem disorder without a clear genetic etiology. A variety of tumors (usually benign) may be seen with the most obvious ones on the skin. However, the nervous system, eyes and bones may also be involved with serious consequences.
Small relatively flat skin lesions called nevi are present at birth on the skin, including the eyelids, the scalp, neck, and even in the mouth. Other growths called dermoids and lipodermoids may be present around the surface of the eye. The eyes may not develop normally with defects in the iris and other colored parts inside the eyeball. Cartilage and bone can develop in abnormal locations such as the coating of the eye. Where the scalp is involved the hair is sparse. Nevi may cover a large area and extend from the scalp to the face and they often enlarge at puberty. A small percentage of the skin lesions can become cancerous.
The brain and nervous system are also involved. Some patients have abnormalities of blood vessels in the brain called aneurysms. Mental retardation and seizures are sometimes evident in the first weeks or months of life. Developmental milestones may be lost and delayed growth and development become evident within several years. The bony skeleton may have growths as well.
This disease does not have a clear-cut etiology although families have been reported in which individuals in multiple generations are affected. It has been suggested that a single lethal mutation may be responsible but selectively involves only some cells which allows some individuals to survive.
The diagnosis requires a multidisciplinary approach involving dermatologists, neurologists, pediatricians and ophthalmologists. There is no known treatment but supportive care for specific symptoms can be helpful. Lifespan may be shortened.