Juvenile polyposis syndrome

Reviewed May 2009

What is juvenile polyposis syndrome?

Juvenile polyposis syndrome is a disorder characterized by multiple noncancerous (benign) growths called juvenile polyps. These growths occur in the gastrointestinal tract, typically in the large intestine (colon). Juvenile refers to the type of polyp, not the age at which polyps develop. People with juvenile polyposis syndrome typically develop polyps during the first two decades of life. The number of polyps varies from only a few to hundreds, even among affected people in the same family. Polyps may cause gastrointestinal bleeding, a shortage of red blood cells (anemia), abdominal pain, and diarrhea. Approximately 15 percent of people with juvenile polyposis syndrome have other abnormalities, such as a twisting of the intestines (intestinal malrotation), heart or brain abnormalities, an opening in the roof of the mouth (cleft palate), extra fingers or toes (polydactyly), and abnormalities of the genitalia or urinary tract.

Juvenile polyposis syndrome is diagnosed when a person has any one of the following: (1) more than five juvenile polyps of the colon or rectum, (2) juvenile polyps in other parts of the gastrointestinal tract, or; (3) any number of juvenile polyps and one or more affected family member.

Three types of juvenile polyposis syndrome have been described, based on the signs and symptoms of the disorder. Juvenile polyposis of infancy is characterized by polyps that occur throughout the gastrointestinal tract during infancy. Juvenile polyposis of infancy is the most severe form of the disorder and is associated with the poorest outcome. Children with this type may develop a condition called protein-losing enteropathy. This condition results in severe diarrhea, failure to gain weight and grow at the expected rate (failure to thrive), and general wasting and weight loss (cachexia). Generalized juvenile polyposis is diagnosed when polyps develop throughout the gastrointestinal tract. In juvenile polyposis coli, affected people develop polyps only in their colon. People with generalized juvenile polyposis and juvenile polyposis coli typically develop polyps during childhood.

Most juvenile polyps are benign, but there is a chance that polyps can turn cancerous (malignant). It is estimated that people with juvenile polyposis syndrome have a 10 to 50 percent risk of developing a cancer of the gastrointestinal tract. The most common type of cancer seen in people with juvenile polyposis syndrome is colorectal cancer.

How common is juvenile polyposis syndrome?

Juvenile polyposis syndrome occurs in approximately 1 in 100,000 individuals worldwide.

What genes are related to juvenile polyposis syndrome?

Mutations in the BMPR1A and SMAD4 genes cause juvenile polyposis syndrome. These genes provide instructions for making proteins that are involved in transmitting chemical signals from the cell membrane to the nucleus. This type of signaling pathway allows the environment outside the cell to affect how the cell produces other proteins. The BMPR1A and SMAD4 proteins work together to help regulate cell growth and division (proliferation) and the activity of particular genes.

Mutations in the BMPR1A gene or the SMAD4 gene disrupt cell signaling and interfere with their roles in regulating gene activity and cell proliferation. This lack of regulation causes cells to grow and divide in an uncontrolled way, which can lead to polyp formation.

Related Gene(s)

Changes in these genes are associated with juvenile polyposis syndrome.

BMPR1A
SMAD4

How do people inherit juvenile polyposis syndrome?

Juvenile polyposis syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

In approximately 75 percent of cases, an affected person inherits the mutation from one affected parent. The remaining 25 percent of cases result from new mutations in the gene and occur in people with no history of the disorder in their family.

Where can I find information about diagnosis or management of juvenile polyposis syndrome?

These resources address the diagnosis or management of juvenile polyposis syndrome and may include treatment providers.

Gene Review: Juvenile Polyposis Syndrome (http://www.ncbi.nlm.nih.gov/books/NBK1469/)
Genetic Testing Registry: Juvenile polyposis syndrome (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0345893)
MedlinePlus Encyclopedia: Colorectal Polyps (http://www.nlm.nih.gov/medlineplus/ency/article/000266.htm)

You might also find information on the diagnosis or management of juvenile polyposis syndrome in Educational resources (http://www.ghr.nlm.nih.gov/condition/juvenile-polyposis-syndrome/show/Educational+resources) and Patient support (http://www.ghr.nlm.nih.gov/condition/juvenile-polyposis-syndrome/show/Patient+support).

General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).

To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

Where can I find additional information about juvenile polyposis syndrome?

You may find the following resources about juvenile polyposis syndrome helpful. These materials are written for the general public.

MedlinePlus - Health information
- Encyclopedia: Colorectal Polyps (http://www.nlm.nih.gov/medlineplus/ency/article/000266.htm)
- Health Topic: Colonic Polyps (http://www.nlm.nih.gov/medlineplus/colonicpolyps.html)
Educational resources - Information pages
- American Medical Association and National Coalition for Health Professional Education in Genetics: Understand the Basics of Genetic Testing for Hereditary Colorectal Cancer (http://www.nchpeg.org/documents/crc/Basics%20of%20genetic%20testing.pdf)
- American Society of Clinical Oncology (http://www.cancer.net/cancer-types/juvenile-polyposis-syndrome)
- Cleveland Clinic: Juvenile Polyps (http://my.clevelandclinic.org/disorders/inherited_colon_cancer/dd_jp.aspx)
- Madisons Foundation (http://www.madisonsfoundation.org/index.php?option=com_mpower&task=disease&diseaseID=410)
- Orphanet (http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=2929)
Patient support - For patients and families
- American Society of Colon and Rectal Surgeons: Inherited Colorectal Cancer Registries (http://www.fascrs.org/patients/family_history_registries/)
- Colon Cancer Alliance (http://www.ccalliance.org/)
- Colorectal Cancer Coalition (http://fightcolorectalcancer.org/)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1469/)
Genetic Testing Registry - Repository of genetic test information
- Genetic Testing Registry: Juvenile polyposis syndrome (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0345893)
PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=(juvenile%20polyposis%20syndrome%5BTIAB%5D)%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201800%20days%22%5Bdp%5D)
OMIM - Genetic disorder catalog (http://omim.org/entry/174900)

What other names do people use for juvenile polyposis syndrome?

BMPR1A-related juvenile polyposis
juvenile intestinal polyposis
SMAD4-related juvenile polyposis

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about juvenile polyposis syndrome?

Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).

What glossary definitions help with understanding juvenile polyposis syndrome?

anemia ; autosomal ; autosomal dominant ; benign ; cachexia ; cancer ; cell ; cell membrane ; cell proliferation ; cleft palate ; colon ; colorectal ; failure to thrive ; gastrointestinal ; gene ; genitalia ; intestine ; juvenile ; mutation ; nucleus ; palate ; polydactyly ; polyp ; polyposis ; proliferation ; protein ; rectum ; syndrome ; wasting

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

Aretz S, Stienen D, Uhlhaas S, Stolte M, Entius MM, Loff S, Back W, Kaufmann A, Keller KM, Blaas SH, Siebert R, Vogt S, Spranger S, Holinski-Feder E, Sunde L, Propping P, Friedl W. High proportion of large genomic deletions and a genotype phenotype update in 80 unrelated families with juvenile polyposis syndrome. J Med Genet. 2007 Nov;44(11):702-9. Epub 2007 Sep 14. (http://www.ncbi.nlm.nih.gov/pubmed/17873119?dopt=Abstract)
Calva-Cerqueira D, Chinnathambi S, Pechman B, Bair J, Larsen-Haidle J, Howe JR. The rate of germline mutations and large deletions of SMAD4 and BMPR1A in juvenile polyposis. Clin Genet. 2009 Jan;75(1):79-85. doi: 10.1111/j.1399-0004.2008.01091.x. Epub 2008 Sep 24. (http://www.ncbi.nlm.nih.gov/pubmed/18823382?dopt=Abstract)
Chow E, Macrae F. A review of juvenile polyposis syndrome. J Gastroenterol Hepatol. 2005 Nov;20(11):1634-40. Review. (http://www.ncbi.nlm.nih.gov/pubmed/16246179?dopt=Abstract)
Howe JR, Sayed MG, Ahmed AF, Ringold J, Larsen-Haidle J, Merg A, Mitros FA, Vaccaro CA, Petersen GM, Giardiello FM, Tinley ST, Aaltonen LA, Lynch HT. The prevalence of MADH4 and BMPR1A mutations in juvenile polyposis and absence of BMPR2, BMPR1B, and ACVR1 mutations. J Med Genet. 2004 Jul;41(7):484-91. (http://www.ncbi.nlm.nih.gov/pubmed/15235019?dopt=Abstract)
Pyatt RE, Pilarski R, Prior TW. Mutation screening in juvenile polyposis syndrome. J Mol Diagn. 2006 Feb;8(1):84-8. (http://www.ncbi.nlm.nih.gov/pubmed/16436638?dopt=Abstract)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.



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