Basal Cell Carcinoma Nevus Syndrome
Basal Cell Carcinoma Nevus Syndrome is a rare condition caused by a genetic mutation which affects the skin and eyes, nervous, endocrine and skeletal systems. First described in 1950 by Dr. J. B. Howell, the mutation for BCCNS commonly results in a predisposition towards the formation of multiple basal cell carcinomas — the most frequent form of skin cancer. Basal cell carcinomas (BCC’s), in syndromic-affected individuals, occur at a significantly higher rate and often appear in the first decade of life. They often manifest areas not commonly exposed to the sun such as the palms, thighs, scalp, and soles of the feet. These skin cancers are stimulated by radiation and there are several documented cases of radiation treatment in undiagnosed patients with tragic results. Other common BCCNS manifestations include invasive cysts of the jaw (odontogenic keratocysts); hand (palmar) or feet (plantar) skin pits; fusion of the cranial bones of the skull (premature calcification of the falx cerebri); curvature & tumors of the spine; skeletal abnormalities; cardiac and ovarian fibromas; and on rare occasion, brain tumors, such as medulloblastoma or meningioma, among others.
The mutated gene inheritance is autosomal dominant. A child has a 50% chance of inheriting this gene from an affected male or female biological parent. Two-thirds of cases in the United States result from the inherited gene of a family member, while the other one-third of persons with BCCNS are the first affected in their entire family. The current incidence of BCCNS is 1 in 40,000 in the US and has steadily increased since first described as awareness of the condition has spread. The severity of the symptoms varies among affected individuals, but 90% will develop multiple invasive BCC’s in their lifetime. Current treatment is supportive — only symptoms are treated since there is no cure. Promising medical treatments are being developed and genetic work is underway to better understand and address the underlying causes of BCCNS.