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GTR Home > Conditions/Phenotypes > Generalized juvenile polyposis/juvenile polyposis coli

Summary

Excerpted from the GeneReview: Juvenile Polyposis Syndrome
Juvenile polyposis syndrome (JPS) is characterized by predisposition to hamartomatous polyps in the gastrointestinal (GI) tract, specifically in the stomach, small intestine, colon, and rectum. The term "juvenile" refers to the type of polyp rather than to the age of onset of polyps. Most individuals with JPS have some polyps by age 20 years; some may have only four or five polyps over their lifetime, whereas others in the same family may have more than 100. If the polyps are left untreated, they may cause bleeding and anemia. Most juvenile polyps are benign; however, malignant transformation can occur. Risk for GI cancers ranges from 11% to 86%. Most of this increased risk is attributed to colon cancer, but cancers of the stomach, upper GI tract, and pancreas have also been reported. A combined syndrome of JPS and hereditary hemorrhagic telangiectasia (HHT) is present in most individuals with an SMAD4 pathogenic variant.

Suggested reading

Practice guidelines

  • ACMG SF v3.0, 2021
    ACMG SF v3.0 list for reporting of secondary findings in clinical exome and genome sequencing: a policy statement of the American College of Medical Genetics and Genomics (ACMG)
  • ACMG, 2016
    Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics.
  • ACG, 2015
    ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes.
  • ACMG/NSGC, 2015
    A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment.
  • NSGC, 2004
    Genetic cancer risk assessment and counseling: recommendations of the National Society of Genetic Counselors. (Retired following 2012 Update)

Consumer resources

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