Gardner Syndrome

Gardner syndrome, a rare genetic disorder, usually causes what start out to be benign or noncancerous growths.

• It is a form of familial adenomatous polyposis (FAP) that is characterized by multiple colorectal polyps and various types of tumors, both benign (noncancerous) and malignant (cancerous).
• People affected by Gardner syndrome have a high risk of developing colorectal cancer at an early age. They are also at an increased risk of developing other FAP-related cancers, such as those of the small bowel, stomach, pancreas, thyroid, central nervous system, liver, bile ducts, and/or adrenal gland.
• Other signs and symptoms of Gardner syndrome include dental abnormalities; osteomas (benign bone growths); various skin abnormalities such as epidermoid cysts, fibromas (a benign tumor of the (connective tissue), and lipomas; and desmoid tumors. It is caused by changes (mutations) in the APC gene and inherited in an autosomal dominant manner.
  • The APC gene provides instructions for making the APC protein, which plays a critical role in several cellular processes. The APC protein acts as a tumor suppressor, which means that it keeps cells from growing and dividing too fast or in an uncontrolled way. It helps control how often a cell divides, how it attaches to other cells within a tissue, and whether a cell moves within or away from a tissue. This protein also helps ensure that the number of chromosomes in a cell is correct following cell division.
    • Other names for this gene: adenomatous polyposis coli; APC_HUMAN; DP2; DP2.5; DP3; FAP; FPC; GS; PPP1R46; WNT signaling pathway regulator.
    • MedlinePlus – APC gene
  • What causes the mutation of this gene has not been determined.
• The syndrome was first described in 1951 by Eldon J Gardner (1909-1989), a geneticist.

Symptoms:

• The signs and symptoms of Gardner syndrome vary from person to person.
• It is characterized primarily by hundreds to thousands of noncancerous (benign) polyps in the colon that begin to appear at an average age of 16 years. Unless the colon is removed, these polyps will become malignant (cancerous), leading to early-onset colorectal cancer at an average age of 39 years.
• Other features of Gardner syndrome may include:
  • Dental abnormalities
  • Fundic gland or adenomatous polyps of the stomach
  • Adenomatous polyps of the small intestines
  • Osteomas (benign bone growths)
  • Congenital hypertrophy of the retinal pigment epithelium (a flat, pigmented spot within the outer layer of the retina)
  • Benign skin abnormalities such as epidermoid cysts, fibromas (a benign tumor of the connective tissues), and lipomas
  • Adrenal masses
  • Desmoid tumors
  • Other types of cancer (small bowel, stomach, pancreas, thyroid, central nervous system, liver, bile ducts, and/or adrenal gland)
• 80%-99% of people have these symptoms
  • Adenomatous colonic polyposis
  • Multiple gastric polyps
• 30%-79% of people have these symptoms
  • Colon cancer
  • Congenital hypertrophy of retinal pigment epithelium
  • Duodenal polyposis
  • Lipoma
  • Thyroid nodule

Diagnosis

Genetic testing is available for APC, the gene known to cause Gardner syndrome. Carrier testing for at-risk relatives and prenatal testing are possible if the disease-causing mutation in the family is known. Because colon screening for those at risk for Gardner syndrome begins as early as age ten years, genetic testing is generally offered to children by this age.

Outlook / Prognosis

• The outlook for people with Gardner’s syndrome varies, depending on the severity of symptoms.
• People who have an APC gene mutation such as that in Gardner’s syndrome have an increasingly high chance of developing colon cancer as they age. Without surgical treatment, almost all people with the APC gene mutation will develop colon cancer by 39 years of age (on average).
• Although there is no cure for Gardner syndrome, management options are available to reduce the risk of cancer. These may include high risk screening, prophylactic surgeries and/or certain types of medications.
• Complete removal of the colon and most of the rectum increases the 5-year survival rate of the patients to nearly 100%.

Resources & additional reading

• NIH – Gardner syndrome
• Healthline – Gardner’s Syndrome. Medically reviewed by Stacy Sampson, DO; Written by: MaryAnn De Pietro, CRT. Updated 20 Dec 2017
• Wikipedia – Gardner’s syndrome
• UpToDate – Gardner syndrome. By: Randall W Burt, MD; last updated: Nov 29, 2018
• News Medical Life Sciences – Gardner Syndrome Symptoms. By: Dr Liji Thomas, MD
• News Medical Life Sciences – What is Gardner Syndrome? By: Sanchari Sinha, PhD
• GrepMed.com – Gardner’s Syndrome (…think of a garden!) Image