Juvenile polyposis syndrome


An autosomal dominant genetic condition characterized by the appearance of multiple juvenile polyps in the gastrointestinal tract. 



Two genes associated with juvenile polyposis syndrome are BMPR1A and SMAD4.



Familial juvenile polyposis may be caused by mutations in the PTEN gene on the long arm of chromosome 10 (10q22.3-q24.1) or mutations in the SMAD4 gene also known as DPC4 gene, located on the long arm of chromosome 18 (18q21.1).




These usually begin appearing before age 20, but the term juvenile refers to the type of polyp, that is benign hamartomas, as opposed to adenoma not to the age of the affected person.



While the majority of the polyps found in juvenile polyposis syndrome are non-neoplastic, hamartomatous, self-limiting and benign, there is an increased risk of adenocarcinoma.



Solitary juvenile polyps most commonly occur in the rectum and present with rectal bleeding. 



Diagnostic criteria for the diagnosis:



More than five juvenile polyps in the colon or rectum;



Juvenile polyps throughout the gastrointestinal tract; 



Any number of juvenile polyps in a person with a family history of juvenile polyposis.



Patients may present with 


rectal bleeding, abdominal pain, diarrhea or anemia. 



Polyps can be sessile or pedunculated hamartomatous polyps, and are typically 


small and multiple growths in the gastrointestinal system. 



Symptoms include: gastrointestinal bleeding, abdominal pain, diarrhea, rectal prolapse, intussusception, and/or gastrointestinal obstruction. 



Patients may experience protein loss, malnutrition, and cachexia.



There is an increased risk of colon cancer. 



Other manifestations  may include clubbing of the finger and toes, failure to thrive, and anemia.



Juvenile polyposis syndrome can occur sporadically in families or be inherited in an autosomal dominant manner.



Gene testing may be useful to ascertain which non-symptomatic family members may be at risk of developing polyps.



Gene testing may be useful  for affected individuals when they decide to start a family, providing reproductive choices.



With juvenile polyps yearly upper and lower endoscopies with polyp excision and cytology may be required.



Malignant transformation of polyps requires surgical colectomy.



While  most juvenile polyps are benign; however, malignancy can occur. 



Lifetime risk of colorectal cancer is 39% in patients with juvenile polyposis syndrome.





Leave a Reply

Your email address will not be published. Required fields are marked *