Basal Cell Nevus Syndrome

Alternative Names

  • BCNS
  • Nevoid Basal Cell Carcinoma Syndrome
  • NBCCS
  • Multiple Basal Cell Nevi, Odontogenic Keratocysts, and Skeletal Anomalies
  • Fifth Phacomatosis
  • Gorlin Syndrome
  • Gorlin-Goltz Syndrome

Associated Genes

Patched 1
Back to search Result
WHO-ICD-10 version:2010

Congenital malformations, deformations and chromosomal abnormalities

Other congenital malformations

OMIM Number

109400

Mode of Inheritance

Autosomal dominant

Gene Map Locus

1p34.1,9q22.32,10q24.32

Description

Basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, is a rare autosomal dominant genetic disorder that affects the skin, endocrine system, nervous system, eyes, bones, and confer susceptibility to various forms of cancers, especially basal cell carcinoma (BCC). The approximate prevalence of basal cell nevus syndrome is reported to be from 1/57,000 to 1/256,000, with a male-to-female ratio of 1:1. It is characterized by five major components, including multiple nevoid basal cell carcinomas, jaw cysts, congenital skeletal abnormalities, ectopic calcifications, and plantar or palmar pits. Other features may also be present.

Clinical diagnosis relies on specific criteria including careful oral and skin examinations, chest and skull radiographs, panoramic radiographs of the jaw, magnetic resonance imaging of the brain, and pelvic ultrasonography in women. Treatments may include surgery for BCC when the number of lesions is limited, laser ablation, photodynamic therapy and topical chemotherapy. BCNS patients should strictly avoid excessive sun exposure. About 5-10% of the patients develop medulloblastoma, which may be a potential cause of early death.

Mutations in the PTCH1 gene are associated with basal cell nevus syndrome. PTCH1 is a tumor suppressor gene, and mutations in this gene prevent the production of patched-1 protein or lead to the production of an abnormal version of this receptor, which leads to uncontrolled proliferation of the cells. Mutations in PTCH2 and SUFU genes have also been identified in BCNS patients. Both these genes are involved in the hedgehog signaling pathway that plays an important role in cellular proliferation during development.

Epidemiology in the Arab World

View Map

Other Reports

Egypt

Satinoff and Wells (1969) described two Egyptian skeletons of the Dynastic Period with anomalies compatible with clinical features of Basal Cell Nevus Syndrome. The first skeleton belonged to a male who died aged between 20-25 years. The skeleton showed the presence of a possible dentigerous cyst in the mandible near the right first molar, bifid rib which showed posterior broadening, a sacrum with incomplete fusion of the lamina, and relative shortening of the 4th metacarpals. The second skeleton belonged to a 60-year old male. This skeleton showed five bone cavities in the maxilla, which were most likely cystic in origin, along with severe tooth attrition. There were six bifid ribs, all broadening posteriorly and anteriorly, slightly enlarged sella turcica, with asymmetrical occipital bone, and relative shortening of the 4th metacarpals.

Saudi Arabia

Alghamdi (2008) described three sisters with Basal Cell Nevus Syndrome. The proband was a 10-year old girl who presented with increasing number of skin tags since 4-years of age. As an infant, she had hydrocephalus and had undergone a shunt operation. She also had borderline intellectual disability. Upon examination, she was found to have multiple skin-colored to brownish soft papules on the face, neck, trunks, and extremities. Some of these papules were pedunculated. There were also palmoplantar pits under the size of 1 mm. She also showed other characteristic abnormalities, including macrocephaly, bossing of the skull, a broad nasal root, ocular hypertelorism, sclera melanocytosis, high arched palate, uplifted nose, and narrow sloping shoulders. Skull X ray revealed calcification of the falx celebri, while X-ray of the hands showed a shortening of the fourth metacarpal bone. Skin biopsy revealed follicular basal cell carcinoma. Two of her younger sisters (aged 8 and 6-years old) had similar clinical features with skin tags, palmoplantar pits, and characteristic facies. The older of these two sisters also presented with hydrocephalus. The parents had first-degree consanguinity, although both were normal, as were all other family members. The proband was treated by snipping off of the pedunculated lesions, followed by cryoptherapy to the base, and photoprotection.

Hellani et al. (2009) described a 15 year-old Saudi boy with nevoid basal cell carcinoma. He presented with multiple jaw cysts that were keratinizing without granular cell layers. He had broad confluent eyebrows, a broad base of the nose, frontal bossing, palmoplantar pits, and pectus excavatum. His intellectual ability was normal. Histopathological examination revealed nests of tumor cells in the superficial dermis, and basaloid proliferation in the upper dermis with follicular differentiation surrounded by a loose mucinous stroma and retraction artifacts. The diagnosis of nevoid basal cell carcinoma was confirmed by the detection of one nucleotide deletion (c.1291delC) in the PTCH1 gene.

© CAGS 2024. All rights reserved.