Gardner Syndrome is a rare, inherited disorder characterized by the development of numerous growths throughout the body. It is recognized as a variant of Familial Adenomatous Polyposis (FAP), a condition that significantly increases an individual’s risk of developing colorectal cancer. Understanding this syndrome, which affects multiple bodily systems, is important for both affected individuals and their families. Awareness helps in early detection and management, potentially improving long-term outcomes.
Understanding Gardner Syndrome
Gardner Syndrome is linked to a mutation in the Adenomatous Polyposis Coli (APC) gene, located on chromosome 5q21-q22. The APC gene normally functions as a tumor suppressor, regulating cell growth.
When a mutation occurs in the APC gene, this regulatory function is disrupted, leading to uncontrolled cellular growth. This results in the formation of numerous polyps, particularly in the colon and rectum. While often inherited, approximately 20% of Gardner Syndrome cases arise from new, spontaneous mutations in the APC gene.
Recognizing the Signs
The manifestations of Gardner Syndrome extend beyond the gastrointestinal tract, presenting a diverse range of symptoms. The most common feature involves adenomatous polyps that develop in the colon and rectum, often numbering in the hundreds or even thousands. These polyps carry a high potential for becoming malignant if left untreated, with nearly all untreated patients developing colorectal cancer before age 40. Polyps can also appear in the upper gastrointestinal tract, including the stomach and small intestine.
Beyond the digestive system, individuals with Gardner Syndrome often develop other growths:
- Osteomas: benign bone growths, frequently found in the jaw and skull.
- Epidermoid cysts (lump-like growths under the skin), fibromas (fibrous tumors), and lipomas (fatty tissue lumps) affecting skin and soft tissues.
- Desmoid tumors: aggressive, non-cancerous fibrous growths that can occur anywhere and pose management challenges.
- Dental abnormalities: extra (supernumerary) teeth, impacted teeth, or odontomas.
- Congenital hypertrophy of the retinal pigment epithelium (CHRPE): dark spots on the retina, typically asymptomatic.
- Increased risk of other cancers: including those of the thyroid, small bowel, pancreas, liver, and adrenal glands.
Diagnosis and Treatment Approaches
Diagnosis of Gardner Syndrome involves clinical evaluation, imaging, and genetic testing. A healthcare provider considers the patient’s symptoms and family history, looking for characteristic growths and inheritance patterns. Endoscopic examinations, such as colonoscopy, visualize and biopsy polyps in the colon and rectum; more than 100 polyps or fewer polyps with a family history suggest the syndrome.
Imaging studies like CT scans or MRIs identify and monitor extra-intestinal manifestations, particularly desmoid tumors. Genetic testing confirms the definitive diagnosis by identifying mutations in the APC gene. These diagnostic methods help confirm the syndrome and assess the extent of its manifestations.
Treatment for Gardner Syndrome is multidisciplinary, focusing on managing symptoms and preventing cancer. Surgical management of colorectal polyps is a primary intervention due to the high risk of colorectal cancer. A colectomy, removing part or all of the colon, is often recommended, especially if 20 to 30 or more polyps are present or if polyps show advanced changes. Management of extra-intestinal growths may include surgical removal, though desmoid tumors can be challenging to treat and may require chemotherapy or other therapies. Ongoing surveillance, including regular endoscopic examinations, monitors for new growths and detects cancerous changes early.
Genetic Factors and Family Screening
Gardner Syndrome follows an autosomal dominant inheritance pattern, meaning only one copy of the mutated APC gene is needed for an individual to develop the condition. An affected individual has a 50% chance of passing the mutated gene to each child.
Genetic counseling is recommended for affected individuals and their families. Genetic counselors explain inheritance risks, discuss testing options, and provide support. Screening at-risk family members is an important aspect of management, involving genetic testing for the APC gene mutation and regular endoscopic surveillance, such as colonoscopies, often beginning in early adolescence (around age 10-12). Early detection through these methods allows for timely intervention, such as prophylactic surgeries or medications, which can significantly reduce the risk of cancer development.