Gardner's syndrome (also known as Gardner syndrome, familial polyposis of the colon, or familial colorectal polyposis) is a subtype of familial adenomatous polyposis (FAP). Gardner syndrome is an autosomal dominant form of polyposis characterized by the presence of multiple polyps in the colon together with tumors outside the colon. The extracolonic tumors may include osteomas of the skull, thyroid cancer, epidermoid cysts, fibromas, as well as the occurrence of desmoid tumors in approximately 15% of affected individuals.
Desmoid tumors are fibrous tumors that usually occur in the tissue covering the intestines and may be provoked by surgery to remove the colon. The countless polyps in the colon predispose to the development of colon cancer; if the colon is not removed, the chance of colon cancer is considered to be very significant. Polyps may also grow in the stomach, duodenum, spleen, kidneys, liver, mesentery, and small bowel. Cancers related to Gardner syndrome commonly appear in the thyroid, liver and kidneys. The number of polyps increases with age, and hundreds to thousands of polyps can develop in the colon.
The syndrome was first described in 1951.
Cause
Gardner syndrome is caused by mutation in the adenomatous polyposis coli (APC gene), located on chromosome 5q21 (band q21 on chromosome 5). FAP is defined by the development of hundreds or thousands of polyps in the colon. Gardner syndrome is set apart as a subtype because, in addition to colonic polyps, there are also extra-colonic growths (both malignant and benign). There are many terms used to describe "APC-associated polyposis condition" including FAP, attenuated FAP, Gardner syndrome, Turcot syndrome, and gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS). There is a movement toward no longer using the terms Gardner Syndrome or Turcot Syndrome since both are part of the FAP spectrum. Gardner syndrome and Turcot syndrome are regarded primarily for historical interest.
Genetics
thumb|right|Gardner syndrome has an autosomal dominant pattern of inheritance.
Gardner syndrome is inherited in an autosomal dominant manner.
Gardner syndrome can be identified based on oral findings, including multiple impacted and supernumerary teeth, multiple jaw osteomas that give a "cotton-wool" appearance to the jaws, as well as multiple odontomas, congenital hypertrophy of the retinal pigment epithelium (CHRPE), in addition to multiple adenomatous polyps of the colon. Gardner syndrome is also associated with familial adenomatous polyposis and may manifest as aggressive fibromatosis (desmoid tumors) of the retroperitoneum.
Desmoid tumors arise most frequently from the aponeurosis of the rectus abdominal muscle of multiparous women. The extra-abdominal form is rare and desmoids of the breast may arise in the mammary gland or may occur as an extension of a lesion arising from the muscles of the chest wall. The incidence of mammary desmoid tumors is less than 0.2% of primary breast neoplasms. In Gardner's syndrome, the incidence ranges from 4% to 17%. Desmoid tumors associated with Gardner's syndrome have been shown to have an alteration of the β-catenin pathway and over express β-catenin.
See also
- Gorlin syndrome
- List of cutaneous conditions
- List of dental abnormalities associated with cutaneous conditions
- List of cutaneous neoplasms associated with systemic syndromes