38. Gardner Syndrome
Definition
Gardner syndrome is a type of familial adenomatous polyposis that also has extracolonic manifestations, including intestinal polyposis, desmoids, osteomas, and epidermoid cysts. The disorder is inherited via an autosomal dominant pattern.
Incidence
The incidence of Gardner syndrome is about 1:7000 live births, of which 80% are of mendelian dominant inheritance and 20% are spontaneous mutations.
Etiology
Gardner syndrome develops as the result of five mutations:
1. Mutation of the APC gene
2. Loss of DNA methylation
3. RAS gene mutation on chromosome 12
4. Deletion of the colon cancer (DCC) gene on chromosome 18
5. TP53 gene mutation on chromosome 17
Signs and Symptoms
• Adrenal carcinoma
• Biliary duct carcinoma
• Congenital hyperpigmentation of the retinal pigment epithelium
• Cushing syndrome
• Desmoid tumor
• Epidermal cysts
• Gastric carcinoma
• Hepatoblastoma
• Impacted teeth
• Multiple colonic polyps
• Multiple duodenal polyps
