Peutz-Jeghers syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Peutz-Jeghers syndrome is characterized by the development of noncancerous growths called hamartomatous polyps in the gastrointestinal tract (particularly the stomach and intestines) and a greatly increased risk of developing certain types of cancer.

Children with Peutz-Jeghers syndrome often develop small, dark-colored spots on the lips, around and inside the mouth, near the eyes and nostrils, and around the anus. These spots may also occur on the hands and feet. They appear during childhood and often fade as the person gets older. In addition, most people with Peutz-Jeghers syndrome develop multiple polyps in the stomach and intestines during childhood or adolescence. Polyps can cause health problems such as recurrent bowel obstructions, chronic bleeding, and abdominal pain.

People with Peutz-Jeghers syndrome have a high risk of developing cancer during their lifetimes. Cancers of the gastrointestinal tract, pancreas, cervix, ovary, and breast are among the most commonly reported tumors.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the STK11 gene (also known as LKB1) cause most cases of Peutz-Jeghers syndrome. The STK11 gene is a tumor suppressor gene, which means that it normally prevents cells from growing and dividing too rapidly or in an uncontrolled way. A mutation in this gene alters the structure or function of the STK11 protein, disrupting its ability to restrain cell division. The resulting uncontrolled cell growth leads to the formation of noncancerous polyps and cancerous tumors in people with Peutz-Jeghers syndrome.

A small percentage of people with Peutz-Jeghers syndrome do not have mutations in the STK11 gene. In these cases, the cause of the disorder is unknown.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

Peutz-Jeghers syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing noncancerous polyps and cancerous tumors. In about half of all cases, an affected person inherits a mutation in the STK11 gene from one affected parent. The remaining cases occur in people with no history of Peutz-Jeghers syndrome in their family. These cases appear to result from new (de novo) mutations in the STK11 gene.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

The prevalence of this condition is uncertain; estimates range from 1 in 25,000 to 300,000 individuals.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal pigmentation of the oral mucosa · Very frequent (99-80%)

An abnormality of the pigmentation of the mucosa of the mouth.

Abnormality of the gastrointestinal tract · Very frequent (99-80%)

An abnormality of the gastrointestinal tract.

Macule · Very frequent (99-80%)

A flat, distinct, discolored area of skin less than 1 cm wide that does not involve any change in the thickness or texture of the skin.

Multiple lentigines · Very frequent (99-80%)

Presence of an unusually high number of lentigines (singular: lentigo), which are flat, tan to brown oval spots.

Gastrointestinal carcinoma · Very frequent (99-80%)

Gastrointestinal hemorrhage · Frequent (79-30%)

Hemorrhage affecting the gastrointestinal tract.

Abdominal pain · Occasional (29-5%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) and perceived to originate in the abdomen.

Abnormality of the gallbladder · Occasional (29-5%)

An abnormality of the gallbladder.

Abnormality of the nose · Occasional (29-5%)

An abnormality of the nose.

Abnormality of the respiratory system · Occasional (29-5%)

An abnormality of the respiratory system, which include the airways, lungs, and the respiratory muscles.

Abnormality of the ureter · Occasional (29-5%)

An abnormality of the ureter. The ureter is the duct by which urine passes from the kidney to the bladder.

Anemia · Occasional (29-5%)

A reduction in erythrocytes volume or hemoglobin concentration.

Biliary tract neoplasm · Occasional (29-5%)

A tumor (abnormal growth of tissue) of the biliary system.

Breast carcinoma · Occasional (29-5%)

The presence of a carcinoma of the breast.

Other findings in the same source

From: Orphanet

Additional reported features include Cervix cancer (Occasional (29-5%)); Esophageal neoplasm (Occasional (29-5%)); Intestinal obstruction (Occasional (29-5%)); Melanonychia (Occasional (29-5%)); Multiple renal cysts (Occasional (29-5%)); Nasal polyposis (Occasional (29-5%)); Neoplasm (Occasional (29-5%)); Neoplasm of the lung (Occasional (29-5%)); Neoplasm of the nose (Occasional (29-5%)); Neoplasm of the small intestine (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Peutz-Jeghers syndrome is Gastroenterology, with a gastroenterologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which digestive symptoms or nutritional changes matter most?
• What question would an endoscopy, scan or laboratory test answer if one is proposed?
• How should persistent pain, bleeding or difficulty eating be followed up?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Peutz-Jeghers syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.