[From gene to disease: basal cell naevus syndrome].

Nevoid basal cell carcinoma syndrome (NBCCS, basal cell naevus syndrome, Gorlin syndrome) is an autosomal dominant disorder, caused by mutations in the PTCH gene mapped to chromosome 9q22.3. It is characterised by multiple basal cell carcinomas, keratocysts of the jaws, palmar and plantar pits, cerebral ectopic calcification and several skeletal anomalies. Occasionally, patients with NBCCS develop other neoplasms, particularly medulloblastomas and ovarian fibromas, indicating that the PTCH gene is a tumor-suppressor gene. Early recognition and careful follow-up are needed. Guidelines for managing these patients are presented.