Skip to Main Content
  • Become an Access Reviewer
  • Clinical Phenotypes
  • OMMBID Advisory banner
  • Ommbid banner
  • Ommbid latest banner



  1. Cowden syndrome (CS) is an autosomal dominant disorder characterized by multiple hamartomas and a risk of breast and thyroid cancers.

  2. The great majority of tumors, including those of the thyroid and breast, are benign. Up to 10 percent of affected individuals develop nonmedullary thyroid carcinoma, and up to 50 percent of affected females develop breast cancer.

  3. The pathognomonic hamartoma is the trichilemmoma, a benign tumor of the infundibulum of the hair follicle.

  4. The susceptibility gene for CS is a tumor-suppressor gene as evidenced by loss of heterozygosity in the PTEN region of 10q23 in various tumors and by transfection.

  5. The CS gene PTEN was isolated by a combination of genetic mapping analyses, somatic genetics, and a candidate gene approach. PTEN, located on 10q23.3, encodes a 403-amino acid protein, which contains a phosphatase signature motif and has sequences homologous to tensin.

  6. PTEN is a dual-specificity lipid phosphatase. PTEN is the 3-phosphatase for phosphotidylinositol-3,4,5-triphosphate and, hence, coordinately regulates the cell survival factor PKB/Akt via the PI3 kinase signaling pathway.

  7. Germ line mutations in PTEN have been found in CS families as well as in the related but distinct hamartoma disorder Bannayan-Ruvalcaba-Riley syndrome. These mutations result in predicted protein truncation or likely loss of function, hence supporting its predicted function as a tumor suppressor.

  8. Somatic mutations of PTEN occur in a broad spectrum of sporadic tumors, which is almost always biallelic. However, alternate mechanisms of PTEN inactivation do occur.

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

OMMBID Full Site: One-Year Subscription

Connect to the full suite of OMMBID content including new and revised chapters that reflect the latest research, image galleries, clinical phenotypes, and more.

$295 USD
Buy Now

Pay Per View: Timed Access to all of OMMBID

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.