Last updated:
2/26/2025
Years published: 1986, 1987, 1990, 1994, 1998, 1999, 2007, 2018, 2025
NORD gratefully acknowledges Cole Hougo, Allen Karottu, and Diego Pavez Gonzalez, University of Notre Dame and Maria J. Baker, PhD, MS, Department of Medicine, Penn State Hershey Medical Center, Penn State Cancer Institute, for assistance in the preparation of this report.
Summary
Peutz-Jeghers syndrome (PJS) is a very rare genetic condition characterized by the development of benign polyps in the stomach and the intestines (gastrointestinal tract) and by distinctive dark spots on the skin and mucous membranes.1,2 Symptoms usually appear during the first decade of life and begin with spots of dark skin freckling (melanocytic macules) around the mouth, eyes, nostrils, fingers as well as inside the mouth (oral mucosa) and around the anus (perianal). Non-cancerous polyps called hamartomas also begin to grow in the gastrointestinal tract of affected individuals around that age. These polyps are located throughout the gastrointestinal tract and can cause nausea, vomiting, abdominal pain, intestinal obstruction and rectal bleeding.1,3,4
Peutz-Jeghers syndrome is caused by changes (variants) in the STK11/LKB1 gene. Inheritance is autosomal dominant. It affects 1/25,000 to 300,000 individuals.3,4
Abdominal surgery or endoscopic procedures might be necessary to remove polyps (polypectomy) to prevent polyps-related complications such as folding of the intestine into itself (intussusception). Affected individuals have an increased risk for intestinal and other cancers. Frequent medical exams and testing are necessary to allow early detection of polyps and cancer.1
Introduction
Peutz-Jeghers syndrome is part of a diverse group of disorders known as hamartomatous polyposis syndromes that involve the growth of multiple polyps in the gastrointestinal tract.
Peutz-Jeghers syndrome was first described in 1895 and was named by the doctors who defined it as a syndrome.
PJS is characterized by the presence of benign growths within the mucous lining of the gastrointestinal system (called polyps or hamartomas) and spots of dark blue to dark brown skin freckling (melanocytic macules) around the mouth, eyes, nostrils, fingers, oral mucosa and anus (perianal). Symptoms can occur throughout life, with onset and severity varying widely. People with PJS may have poor mental health due to their syndrome.5,6
Melanocytic macules can appear as early as the first year of life and are present in most affected children under five years of age. They tend to fade away with age and might completely disappear in puberty or adulthood, although those inside the mouth usually persist.
Polyps also begin to grow within the first decade of life, but associated symptoms typically arise between 10 to 30 years of age. Polyps most often tend to develop in the small intestine (in the jejunum, specifically) but can also arise in the stomach and large intestine. Rarely, polyps can grow outside the gastrointestinal tract and affect the ureters, bladder, lungs, bronchi and gallbladder. Gastrointestinal polyps can cause the following symptoms:1
People with PJS have a higher risk of developing cancer, especially in the digestive system and other organs. The cancers linked to PJS include:1
These tumors require early monitoring, especially SCTAT for females (causing irregular or heavy periods) and Sertoli cell tumors for males (causing breast development).4 The lifetime risk of developing cancer in affected people varies between 37% to 93%.7
Around 94% of people diagnosed with PJS have an identified variant in the STK11 gene.10 The penetrance of these variants is thought to be essentially 100%, meaning that a person carrying a pathogenic variant in the STK11 gene will always develop features characteristic of PJS.11
People in whom no variant can be identified may have less severe disease with fewer small intestine polyps and a lower cumulative risk for intussusception.12 There is not much difference in the cancer rate between people with and without a detectable STK11 variants but longer follow-up of these patients may be necessary.
The exact mechanism for the dark pigmented spots (melanocytic macules) is unknown, but one idea is that they are caused by inflammation and blockage of melanin migration from cells where it is produced (melanocytes) to cells forming the outermost layer of the skin (keratinocytes).14
PJS follows autosomal dominant inheritance. Dominant genetic disorders occur when only a single copy of a disease-causing gene variant is necessary to cause the disease. The gene variant can be inherited from either parent or can be the result of a new (de novo) changed gene in the affected individual that is not inherited. The risk of passing the gene variant from an affected parent to a child is 50% for each pregnancy. The risk is the same for males and females.
Peutz-Jeghers syndrome is a rare disorder that affects males and females in equal numbers and can occur in any racial or ethnic group. The birth prevalence of PJS is estimated to be between 1/25,000 and 300,000.1 Affected females are at a slightly higher risk of developing cancer compared to males, as PJS increases the likelihood of developing breast, ovarian, cervical and uterine cancer.
A clinical diagnosis of Peutz-Jeghers syndrome can be made when a person has two or more of the following features: 24
Melanocytic macules can be identified with a physical examination. Polyps can be detected from an endoscopy, colonoscopy, or small-bowel endoscopy, which are minimally invasive procedures that use a flexible tube with a camera to view the gastrointestinal tract.
Genetic testing is recommended for any person meeting the above clinical diagnostic criteria or with a family history of PJS. Genetic testing is very useful when a STK11 variant has already been identified in a family member. People with a disease-causing STK11 variant essentially have a 100% chance of developing PJS features.
Treatment
There is no cure for PJS, so treatment focuses on regular monitoring to detect and manage polyps, symptoms and cancer risks as early as possible. Below are the latest screening guidelines for children and for adults developed by the National Comprehensive Cancer Network (NCCN version 3.2024).24
Surveillance for children
The goal is to detect polyps and cancers early. If symptoms appear earlier or complications arise, testing should start sooner.
Surveillance for adults
More screenings are introduced in adulthood to continue monitoring for polyps and cancers.
Women who do not plan to have more children may consider a total hysterectomy (removal of the uterus and cervix) to reduce cancer risk.
Polyps larger than 1 cm are removed to prevent complications such as:4
If the dark pigmented spots (melanocytic macules) cause major emotional impact, laser treatment may help partially lighten or remove them.25
Genetic testing and counseling are recommended for people with PJS and their family members to help them understand their risks and management options.
Some research has hypothesized that COX-2 inhibitors may reduce polyp size in affected individuals but there is currently not enough evidence.26 Some researchers have stated that an mTOR inhibitor (rapamycin 1) was successful in achieving a partial remission in the treatment of pancreatic cancer in a patient with Peutz-Jeghers syndrome.27
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]
Some current clinical trials also are posted on the following page on the NORD website:
https://rarediseases.org/living-with-a-rare-disease/find-clinical-trials/
For information about clinical trials sponsored by private sources, contact: www.centerwatch.com
For information about clinical trials conducted in Europe, contact: https://www.clinicaltrialsregister.eu/

NORD strives to open new assistance programs as funding allows. If we don’t have a program for you now, please continue to check back with us.
NORD and MedicAlert Foundation have teamed up on a new program to provide protection to rare disease patients in emergency situations.
Learn more https://rarediseases.org/patient-assistance-programs/medicalert-assistance-program/Ensuring that patients and caregivers are armed with the tools they need to live their best lives while managing their rare condition is a vital part of NORD’s mission.
Learn more https://rarediseases.org/patient-assistance-programs/rare-disease-educational-support/This first-of-its-kind assistance program is designed for caregivers of a child or adult diagnosed with a rare disorder.
Learn more https://rarediseases.org/patient-assistance-programs/caregiver-respite/The information provided on this page is for informational purposes only. The National Organization for Rare Disorders (NORD) does not endorse the information presented. The content has been gathered in partnership with the MONDO Disease Ontology. Please consult with a healthcare professional for medical advice and treatment.
The Genetic and Rare Diseases Information Center (GARD) has information and resources for patients, caregivers, and families that may be helpful before and after diagnosis of this condition. GARD is a program of the National Center for Advancing Translational Sciences (NCATS), part of the National Institutes of Health (NIH).
View reportOrphanet has a summary about this condition that may include information on the diagnosis, care, and treatment as well as other resources. Some of the information and resources are available in languages other than English. The summary may include medical terms, so we encourage you to share and discuss this information with your doctor. Orphanet is the French National Institute for Health and Medical Research and the Health Programme of the European Union.
View reportOnline Mendelian Inheritance In Man (OMIM) has a summary of published research about this condition and includes references from the medical literature. The summary contains medical and scientific terms, so we encourage you to share and discuss this information with your doctor. OMIM is authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine.
View reportGeneReviews has an article on this condition covering diagnosis, management, and inheritance. Each article is written by one or more experts on the specific disease and is reviewed by other specialists. The article contains medical and scientific terms, so we encourage you to share and discuss this information with your doctor. The GeneReviews database is managed by the University of Washington.
View reportMedlinePlus has information about this condition that may include a description, frequency, causes, inheritance, and links to more information. The information is written for the public, including patients, caregivers and families. MedlinePlus is a service of the National Library of Medicine (NLM), which is part of the National Institutes of Health (NIH).
View reportPlease complete this form to access the requested resource.