What is Gorlin Syndrome?
Gorlin syndrome is also known as Nevoid Basal Cell Carcinoma Syndrome or Basal Cell Nevus Syndrome. It is a rare genetic disorder characterized by the development of multiple basal cell carcinomas resulting in multiple defects of the body in general.
People with Gorlin syndrome have increased chances for developing various tumors which may or may not be cancerous and the most common is the basal cell carcinoma. The multiple organ abnormalities involved in Gorlin syndrome are the result of the aberration in certain gene particularly of PTCH1 gene.
Gorlin syndrome is marked by the onset of basal cell carcinoma during the stage of puberty. It equally affects both men and women without racial predilection. The risk for developing multiple basal cell carcinoma accounts for about 90% of individuals with Gorlin syndrome while 5% of children will develop medulloblastoma.
There are about more than a million of diagnosed basal cell carcinoma each year but only a few percentages or approximately about 1% of which is involved with Gorlin syndrome. The disease is regarded to be a rare autosomal dominant condition that is common among individuals over the age of 40 years, believed as a result of prolonged exposure under the sunlight. One of the hallmarks of Gorlin syndrome however is the onset of multiple basal cell carcinomas that often occurs at an early age particularly during the teenage years.
The symptoms of Gorlin syndrome greatly vary although not all patients will have the same signs and symptoms and not all the symptoms will be experienced by the patient.
Gorlin syndrome is divided into major and minor criteria which are essential in diagnosing the disease. The criteria are essential in determining the treatment program for a particular patient. The diagnosis of Gorlin syndrome is based on the criteria manifested by the patient. The diagnosis should be in the presence of 2 major criteria or at least 1 major and 2 minor criteria.
The major criteria for Gorlin syndrome should include the following manifestations:
- Basal cell carcinoma which is the hallmark of Gorlin syndrome. There should be the presence of 1 or 2 basal cell carcinomas that occur in patients below the age of 20 years. Basal cell carcinoma often develops in the area of the head or neck. The tumor in basal cell carcinoma is characterized by its pearly like nodule that is rather shiny in texture. It does not have the ability to spread but is capable of invading the surrounding tissues thereby causing a significant disfigurement.
- Keratocystic odontogenic tumor is among the major criteria that develop in the jaw either in the mandible or in the maxilla. The growth is usually benign but can be aggressive which can grow large enough to cause deformity in the jaw and teeth.
- Palmar or plantar pits are characterized by the appearance of tiny pits in the skin of the palm of the hands and soles of the feet. The pits become visible especially when soaked in warm water or is more obvious in people with manual job such holding grease and other dirt.
- Calcification of the dura mater is seen in patient with Gorlin syndrome. Dura mater generally thickens or calcifies with age which is not the case in people with Gorlin syndrome who tend to have thickened dura mater at an early age.
The minor criteria for Gorlin syndrome include the following:
- Macrocephaly describes the head of the patient with a size that is larger than the average.
- Congenital malformations such as cleft lip and cleft palate including a prominent brow line or frontal bossing which makes the eyes appear sunken.
- Eyes set wider than the normal or the condition known as orbital hypertelorism.
- Skeletal deformities such as Sprengel deformity which is described as the shoulder blade smaller than the usual and situated higher on the back as compared to the other shoulder.
- Pectus is also another skeletal deformity which is characterized by the improper development of the breast bone.
- Syndactyly is included in the skeletal abnormalities and is characterized by an abnormal fusion of the fingers or toes.
- Hemivertebrae is a radiologic abnormality where the vertebrae of the patient is unable to develop properly thus resulting in problems with posture.
- Ovarian fibroma is described as a growth of tumor in the ovary. The fibroma often hardens or calcifies in patient suffering from Gorlin syndrome.
Other common symptoms of Gorlin syndrome include the following:
- Hyperpneumatization of paranasal sinuses which is believed to occur as a result of Gorlin syndrome involving the growth and development of the skull.
- Spina bifida occurs when the vertebrae that covers the spinal cord fails to develop.
- Skin tags may develop in multitude in patient with Gorlin syndrome.
Gorlin Syndrome Causes
Gorlin syndrome is a genetic disorder that involves the mutation of PTCH1 gene. The syndrome is inherited in an autosomal dominant pattern. One copy of the altered gene is sufficient enough to trigger the onset of Gorlin syndrome. This means that a child can inherit the genetic mutation even with only one affected parent.
PTCH1 is a gene responsible for suppressing tumor from proliferating rapidly. The mutation in the PTCH1 gene results to the abnormality in its function thereby resulting in the inability to suppress the tumor from proliferating. When the gene is unable to control the tumor from proliferating, it will form into a tumor that describes the Gorlin syndrome. On the other hand, the association between the PTCH1 mutation and the manifestations of the syndrome remains vague.
Microdeletion of 9q22.3 chromosome is being associated with the onset of signs and symptoms in Gorlin syndrome. The deletion may include a piece of the chromosome 9 that contains the PTCH1 gene.
Gorlin syndrome can be passed on to offspring even with one copy of the mutated PTCH1 gene. The syndrome is passed on in an autosomal pattern which makes one copy of the mutated gene sufficient enough to cause Gorlin syndrome. On the other hand, Gorlin syndrome may also occur in individuals without a family history of Gorlin syndrome.
Gorlin Syndrome Treatment
The treatment for Gorlin syndrome is often surgical. The method of treatment, however, requires a careful evaluation to determine the type of treatment in relation to the clinical findings.
Pharmacological treatment may not prove to be a complete cure but it can be beneficial to patients with multiple skin lesions. Smaller lesions may be treated with pharmacological treatment despite its low cure rate.
Pharmacological treatment may include the following:
Fluorouracil cream or 5-Fluorouracil is applied topically and acts by obliterating the skin cells damaged by exposure under the sunlight.
Imiquimod cream is a topical agent usually prescribed in Gorlin syndrome with tiny skin lesions. This drug acts by stimulating the immune system to release cytokines that is vital in obliterating cancer cells and to fight harmful agents as well such as virus and bacteria.
Surgical excision of the tumor is the most preferred method of treating Gorlin syndrome. Cure rate and potentials for scarring should be considered prior to surgical removal of the lesions. The surgical method on the other hand depends on where the tumor developed and how far the tumor has extended.
The life expectancy in Gorlin syndrome is not different from the average while morbidity is associated with the complications. The main problem is related to the cosmetic aspect in relation to the development of multiple skin tumors which can cause a significant deformity of the face, including the unappealing appearance of the skin tumors in other parts of the body. The cosmetic concern may cause low self-esteem in the patient and may result to social dilemmas.