In my latest article, I mentioned that among the causes of basal cell carcinoma is a disorder called Gorlin syndrome. In this article, I will explain what Gorlin syndrome is and how it can be treated. Gorlin syndrome, also known as nevoid basal cell carcinoma syndrome, and is a rare, autosomal (affecting the non-sex chromosomes) dominant condition (meaning only one parent needs to have it for their children to have it). It can cause the early onset of basal cell carcinoma in addition to several other forms of skin cancer, including melanoma, medulloblatoma, meningioma, and several others (1). Gorlin syndrome is estimated to affect one in every 50,000 to 100,000 people (1).
What causes Gorlin syndrome? Gorlin syndrome results from an abnormality of the PTCH1 gene on chromosome 9q22.3-q31 (1). The PTCH1 gene produces protein patched homolog 1, a receptor for sonic hedgehog (I am not making this up, the hedgehog signaling pathway is responsible for embryonic development. That was surprising to learn in biology class). The sonic hedgehog molecule functions as a tumor suppressor. Mutations producing a faulty PTCH1 gene disrupt this process, and can allow tumor growth.
Diagnosis of the Gorlin syndrome is based on examination of several criteria. Major criteria are: the development of multiple basal cell carcinomas at any age, multiple palmar or plantar pits (skin lesions), a family history of Gorlin syndrome, polyostotic bone cysts, odontogenic keratocysts, calcification of the falx cerbri and ectopic calfication (1). In addition to these major criteria, there are several minor ones: the presence of cardiac or ovarian fibroma (benign tumors in the heart or ovaries respectively), medulloblastoma, lymphomesenteric cysts, congenital skeletal defects, a large head with occipitofrontal circumference and congenital malformation (1). The presence of these varied tumors and growths are not always indicative, but expressing at least two major criteria and a minor is generally an indication of Gorlin syndrome (2).
Fortunately, there are methods to manage Gorlin syndrome. Since detection of Gorlin syndrome usually involves the presence of a tumor or growth, chemotherapy and surgery is generally required for the patient. Since Gorlin syndrome results from a genetic defect, it may require treatment throughout one’s lifetime. Use of oral retinoids such as isotretinoin or acitretin may be prescribed by dermatologists for certain cases. Since individuals with Gorlin syndrome are more susceptible to tumor formation, treatments should avoid radiation as this may cause the development of more tumors(1). In addition, proper skin protection is important, as this can prevent development of skin cancers. If you are concerned about Gorlin syndrome, get an appointment for genetic counseling to see if you or your parents were carriers.