Gardner's syndrome

Cause

Gardner syndrome results from a mutation in the adenomatous polyposis coli (APC) gene on chromosome 5q21, the same gene responsible for familial adenomatous polyposis (FAP), a more common condition that raises colon cancer risk. Over time, Gardner syndrome has been reclassified as a phenotypic subtype of FAP, which is defined by hundreds to thousands of colon polyps.

What sets Gardner syndrome apart are additional extra-colonic growths, both benign and malignant. The broader group of APC-associated polyposis conditions includes FAP, attenuated FAP, Gardner syndrome, Turcot syndrome, and gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS). There is now a push to stop using the terms Gardner syndrome and Turcot syndrome, as they are considered primarily of historical interest within the FAP spectrum.

Diagnosis

Gardner syndrome involves adenomatous polyps in the gastrointestinal tract, along with Gardner fibromas, desmoid tumors, osteomas, epidermoid cysts, lipomas, dental issues, and periampullary carcinomas. In the mouth, signs include multiple impacted or extra teeth, jaw osteomas that create a cotton-wool look, odontomas, and congenital hypertrophy of the retinal pigment epithelium. This condition is linked to familial adenomatous polyposis and can cause aggressive fibromatosis in the retroperitoneum. Desmoid tumors in Gardner syndrome show changes in the β-catenin pathway and overexpress β-catenin.

Did You Know?

• Desmoid tumors arise most frequently from the aponeurosis of the rectus abdominal muscle of multiparous women.
• Each child of a parent with Gardner syndrome has a 50% risk of inheriting the gene.
• Treatments for desmoid tumors may include NSAIDS, anti-estrogen medications, and radiation therapy.