This rare, childhood-onset disease is an autosomal dominant disorder that results from mutations in various cancer susceptibility genes, including the SMAD4/DPC4 and BMPR1A genes. The condition is associated with the development of hamartomatous polyps (few to numerous) that can be present throughout the gastrointestinal tract. Symptoms can include: Diarrhea Hemorrhage Protein-losing enteropathy Juvenile polyposis is associated with an increased chance for gastrointestinal and pancreatic cancers. Most patients appear to be sporadic cases (happening for the first time in a family). However, this may actually be the result of decreased penetrance (i.e., the causative gene mutation is present in one of the parents but the symptoms did not develop).