Generalized juvenile polyposis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 5, 2017
StartDiseasesGeneralized juvenile polyposis

Generalized juvenile polyposis, sometimes also called juvenile intestinal polyposis, causes noncancerous polyps to grow in the digestive tract. Polyps usually appear before the second decade of life, can grow throughout the digestive system, and elevate gastrointestinal cancer risk.

Contents

Definition & Facts

There are three types of the syndrome with juvenile polyposis of infancy being the most severe form. Polyps form throughout a baby's digestive tract and can cause general wasting through protein starvation. Juvenile polyposis coli involves the growth of polyps in the colon only. Regardless of type, polyps raise one's risk for:

Polyps can be flat and smooth or tubular, projecting into the colon's center. They can also return after surgical removal.

Symptoms & Complaints

An individual may feel tired for no reason or lose weight without dieting. As fecal matter passes across polyps, they may tear and bleed, leading to anemia and dizziness when standing.

The slow blood loss can also cause oxygen-starved muscles to cramp and patients may see rectal bleeding or bloody stool. Food moving past affected areas can cause pain and the bowel can occasionally twist around larger polyps.

Polyps can cover most of the stomach lining, interfering with digestion and triggering vomiting while polyps infiltrating the intestines can create blockages. The resulting nutritional impact can result in thinning hair, changes in the skin and brittle nails in older children and adults. However, babies fail to thrive. Many individuals with generalized juvenile polyposis also have:

Hereditary hemorrhagic telangiectasia (HHT), a congenital blood vessel abnormality may be present. Bleeding from the dilated blood vessels associated with HHT coupled with bleeding from juvenile polyps makes anemia more likely.

Causes

A mutation in two genes causes generalized juvenile polyposis, but it takes just one to cause the syndrome. It is normally inherited from one parent in an autosomal dominant pattern. However, there are instances of juvenile polyposis without a family history.

Signals from proteins tell cells when to grow, divide and die. A genetic mutation alters a protein behavior and its signals. The altered protein sends cells the wrong signals, triggering abnormal cell growth along the mucous membrane lining the digestive tract. Illnesses occurring during pregnancy can damage a baby's genes before birth, as can radiation exposure, and cause errors in DNA replication.

Diagnosis & Tests

Physicians diagnose juvenile polyposis when they see five or more polyps in the colon or rectum when polyps appear in other parts of the digestive tract or family members have had them. A doctor seeing unexplained weight loss and fatigue in a patient may order a barium enema to reveal bleeding polyps. To rule out other disorders, they also test:

Additionally, they order colonoscopies, sigmoidoscopies, or upper endoscopies to answer questions about polyp sizes and locations. Laboratories examine tissues from removed polyps to determine their nature. In 2014, the Food and Drug Administration approved capsule endoscopy. Patients can now swallow a camera-loaded pill that takes pictures as it moves through the digestive system.

Treatment & Therapy

An internist or family doctor will first monitor a patient for rectal bleeding, diarrhea, and abdominal pain. They also ask about stool shape, color and size.

Changes can lead to a colonoscopy for polyp removal (polypectomy), the preferred method for managing the disease. With severe polyp infiltration, surgeons remove all or part of the gastrointestinal tract. The doctor may suggest taking dietary supplements to replace nutrients. Someone with a family history of juvenile polyps has endoscopic screenings beginning at age 15 or when symptoms appear. Their endoscopic examinations and polyp removals repeat every two to three years.

When patients have polyps, treatments repeat yearly until the patient is polyp-free. Physicians also counsel patients about elevated cancer risks and may suggest additional cancer screenings. Professionals also understand the psychological stress the syndrome can cause and may monitor patients for depression. A physician may recommend a counselor or psychotherapist to help with the emotional impact of having the disorder and coping with treatment. Therapy can also include joining a support group.

Prevention & Prophylaxis

Since this genetic abnormality can cause cancer and can accompany other congenital abnormalities, an individual with a family history of polyposis may seek genetic counseling before having children. After discovering the syndrome, a doctor will suggest genetic testing for other close relatives and colonoscopies for those with the genetic mutation.

Physicians start monitoring at-risk children during early childhood to protect their development. Otherwise, doctors focus on managing secondary disorders and preventing complications. They may prescribe dietary supplements when they see weight loss and anemia, but there are no medications to prevent or directly treat juvenile polyposis.

People over the age of 50 and those with family histories of juvenile polyps have colonoscopies for polyp removal. Physicians consider prophylactic surgery when individuals are severely anemic, treatment by colonoscopy is impossible, the patient has severe gastric bleeding or their family has a strong history of the syndrome.

Polyps can return after partial colon removal (subtotal colectomy). For this reason, doctors recommend a total removal of the rectum and colon (complete proctocolectomy) as the first surgery for people with massive polyposis, and when endoscopy will not provide effective treatment. Individuals who have already had surgery also see their doctors for follow-up endoscopies to check for new polyps.