Polyposis Syndromes: Tests and Diagnosis

What tests are used to diagnose polyposis syndromes?

Doctors take a blood sample to help identify which type of polyposis a patient has, based on genetic markers for the disease. However, mutations are not always detectable. For most of these disorders, the presence of one mutation is enough to make the diagnosis.

Genetic testing is available for JPS (genetic markers SMAD4 and BMPR1A), PJS (genetic marker STK11), and FAP (genetic markers APC, MUTYH).  

To closely examine a patient’s polyps, a doctor may use different imaging methods including endoscopy, colonoscopy, and enteroscopy. These tools help determine the number, size, distribution and microscopic characteristics of the polyps to help guide a patient’s treatment decisions.

Why choose Children’s Hospital Colorado for polyposis syndromes testing?   

Children’s Hospital Colorado offers comprehensive evaluation in an environment focused only on kids.  For our patients undergoing diagnostic evaluation or interventional procedures, the team is pediatric-trained and the equipment is sized especially for the child. Child-life specialists help prepare children for surgical procedures, reducing their anxiety.  The décor and activities in the waiting and exam rooms are designed to appeal to children and distract them. The laboratory provides trained technicians to draw blood using the smallest needles and volume that are appropriate.

What to expect from polyposis syndromes testing  

Children’s Colorado focuses on the patient’s experience.  From the clinic rooms to the operating and recovery rooms, the environment is kid-friendly. Before procedures, a play therapist is available to meet with families and show pictures to explain the process and reassure children.  Procedures are usually done under anesthesia.  When possible, blood draws are done under the same anesthesia.  Recovery rooms have child friendly activities and foods and drinks. 

How do doctors at Children’s Colorado make a diagnosis?

Juvenile polyposis syndrome 
JPS is diagnosed through a combination of genetic testing for the SMAD4 and BMPR1A mutations and polyp identification if no known genetic mutation is found. Patients with JPS have more than five juvenile polyps in their colon or rectum, juvenile polyps in other parts of the GI tract, or at least one juvenile polyp plus an affected family member.  

Peutz-Jegher syndrome 
PJS usually have a characteristic polyp and typical dark pigmentation patterns usually around the mouth and lips. Identifying a mutation in the STK11 gene is also used to make a diagnosis.

Familial adenomatous polyposis 
Patients with multiple adenomas, a type of non-cancerous tumor, in the colon are usually diagnosed with FAP. Doctors may perform genetic testing to find mutations in the APC gene for the classic or attenuated form, or in the MUTYH gene for the autosomal recessive form of the disease.