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Peutz-Jeghers Syndrome (PJS)

Peutz-Jeghers syndrome (PJS) is a genetic condition that causes non-cancerous growths to develop in the digestive system. It can also increase the risk of developing other types of cancer.

The growths, called hamartomatous polyps, usually grow in the small intestine. They can also grow in the:

  • Stomach
  • Large intestine
  • Kidneys
  • Lungs
  • Gall bladder
  • Nasal passages
  • Bladder
  • Tubes that connect the kidneys to the bladder

Cancer risk with Peutz-Jeghers syndrome

Having PJS increases a person’s risk of developing the following types of cancers:

  • Digestive system cancer, including stomach, esophagus, small intestine, pancreas, colon, or rectum
  • Breast cancer
  • Uterine cancer
  • A rare type of cervical cancer
  • Lung cancer
  • Tumors of the ovaries and testicles that can be cancerous or non-cancerous

Other types of cancers can also happen in people with PJS.

Because PJS is inherited, it can be passed from parents to children. PJS often varies in how severe it is, even among people in the same family. Some people may have many polyps and may develop cancer at an early age. Others may only develop a few polyps and may not develop cancer.

People with PJS have an 85% risk of developing cancer by age 70. The risks for each type of cancer are shown in the table below:

Type of Cancer Lifetime Risk

Breast cancer


Colorectal cancer


Pancreatic cancer


Stomach cancer


Ovarian cancer


Lung cancer


Cervical cancer


Other health problems with Peutz-Jeghers syndrome

People with PJS may have other medical issues. Not all people with PJS will have all of the symptoms or health conditions listed below.

The growth of polyps in the digestive system may cause:

  • Bowel obstruction: A blockage in the large or small intestine
  • Rectal prolapse: Lowest part of the large intestine protrudes through the anus
  • Severe bleeding in the digestive system
  • Anemia: Too little oxygen in the blood, which causes the person to feel tired

Tumors of the ovaries and testicles may cause:

  • Puberty that happens earlier than normal
  • Irregular or heavy menstrual periods in women
  • Growth of breasts in boys
  • Unusually short height in boys.

Signs of Peutz-Jeghers syndrome

People with PJS often have small, dark-colored spots that look like freckles on parts of their skin. The spots usually appear during childhood. Most spots are on the lips, around and inside the mouth, near the eyes and nostrils, and around the anus. The spots may also occur on the hands and feet. They often fade as the person gets older.

Causes of Peutz-Jeghers syndrome

Genes carry information telling cells in the body how to function. Peutz-Jeghers syndrome is caused by changes in a gene known as STK11. This gene helps tell cells how to grow and divide the right way.

How Peutz-Jeghers syndrome is inherited

Most people without PJS carry 2 working copies of the STK11 gene in their cells. The mother passes down 1 copy. The father passes down the other. Cells from people with PJS carry 1 working copy of the STK11 gene in their cells and 1 copy that is changed. This change causes the STK11 gene to not work right. When a gene change causes a disorder or disease, it is called a gene mutation.

About 50% (1 in 2) of children with PJS have inherited the STK11 gene mutation from a parent. The other 50% of children with PJS are the first people in their families to have the STK11 gene mutation. These children do not have a history of the condition in their families. In these cases, the change either happened in an egg or a sperm cell or it happened in one of the child’s cells during pregnancy. These children are the first in their families to have PJS.

No matter how they got the mutation, people with PJS have a 50% (1 in 2) chance of passing it on to their children.

 Learn more about genetic counselors and understanding genetic risk.

Diagnosis of Peutz-Jeghers syndrome

Health history

A health care provider may suspect that your child has PJS after studying their medical and family cancer history.

This information helps the health care provider and the genetic counselor know if:

  • There are multiple family members with tumors
  • These tumors occurred at younger-than-expected ages
  • The tumors are those that are seen in PJS
  • Family members have freckling in and around the mouth or on hands

Your provider or genetics counselor may recommend STK11 genetic testing if they suspect PJS.

Learn more about types of genetic testing. 

Genetic testing for Peutz-Jeghers syndrome

A blood sample is sent to a genetic testing lab. The lab runs genetic tests that looks for changes in the STK11 gene.

If your child has an STK11 mutation, the genetic counselor will work with your family to:

  • Find out if other family members should consider testing for an STK11 mutation
  • Help your family understand the increased cancer risk from PJS
  • Give you information to help with your decisions about prenatal genetic testing

Genetic testing before or during pregnancy

Parents may choose to do prenatal testing to find out if a pregnancy is affected with a known STK11 mutation. Testing may take place either before pregnancy occurs or during pregnancy.

You should work with a genetic counselor to review the pros and cons of the test. The genetic counselor can also help you prepare for the test results.

Testing before pregnancy is called preimplantation genetic testing (PGT). This special type of genetic testing is done along with in vitro fertilization (IVF). PGT tests embryos for a known STK11 mutation before a provider places the embryo into the uterus.

Testing during pregnancy can help providers see if a pregnancy has a known STK11 mutation. A doctor gathers cells from the pregnancy in 1 of 2 ways:

  • Chorionic villus sampling (CVS) is done during the first 3 months of pregnancy (1st trimester).
  • Amniocentesis is done after the first 3 months of pregnancy (2nd trimester or later).

After tissue collection, the lab checks the sample for the STK11 mutation. Both tests carry minor risks. Discuss risks with an experienced health care provider or a genetic counselor.

Special concerns for genetic testing

Take time to think carefully about the benefits and risks of genetic testing. Speak with a genetic counselor before testing. If you decide to get tested, talk with your health care provider or a genetic counselor about your results so you can understand what they mean.

Sometimes, children or adults with PJS feel sad, anxious, or angry after getting their test results. Parents may feel guilty if they pass the STK11 gene mutation to 1 or more of their children. People with a STK11 gene mutation may also have trouble getting disability or life insurance.

Read more about genetic discrimination

Monitoring and follow-up care for Peutz-Jeghers syndrome 

Children with PJS need regular screenings to detect cancer as early as possible. Get cancer screening in a center that has experience taking care of people with PJS.

All people with this condition should be screened. The goal of screening is to find and treat growths early for the best outcome. Talk about the benefits and risks of cancer screening with a doctor who knows the condition well.

The following guidelines for cancer screening in children and young adults with PJS are recommended:

Stomach and intestinal cancer screening

  • An upper endoscopy, using a small camera to see inside the food pipe and stomach, plus small bowel exam (MR enterography or wireless capsule endoscopy) should be done beginning at age 8. The doctor will decide how often to repeat tests based on results. If polyps are found, repeat in 3 years. If no polyps are found, repeat at 18 years.
  • Colonoscopy, using a small camera to see the inside lining of the colon, begins at age 8. The doctor will decide how often to repeat tests based on results. If polyps are found, repeat the imaging in 3 years. If no polyps are found, repeat at 18 years.

Breast cancer screening

Girls begin screening at age 25 or 5–10 years before the earliest diagnosis of breast cancer in the family, whichever is earlier. This screening includes the following:

  • Breast self-exam monthly
  • Breast exam by a health care provider every 6 months
  • MRI of the breasts and mammogram annually

Pancreatic cancer screening

MRI of the pancreas and bile ducts begins at age 30 and is repeated every 1–2 years. An endoscopic ultrasound combining endoscopy and ultrasound to let the health care provider see the digestive tract may be done instead of MR imaging.

Uterus, ovary, and cervix cancer screening

  • Exam by a gynecologist and Pap smear test beginning at age 18–20 and repeated every year.
  • Consider transvaginal ultrasound, a test where a health care provider uses ultrasound to see the uterus, cervix, and ovaries, and serum CA-125 lab work.

Testicle cancer screening

A testicular exam is used to observe enlargement, masses, or evidence of feminizing changes, beginning at the age of diagnosis.

Suggested screenings may change over time as doctors learn more about PJS. Talk about all screening options with your care team. Because PJS is a complex condition, seek out an experienced doctor for your child. Yearly physical exams should be done by a health care provider who knows PJS well.

Living with Peutz-Jeghers syndrome

People of any age with PJS have a higher risk of cancer. It is important to monitor children’s health and help them adopt healthy habits. They need to have regular physical checkups and screenings. That way, the care team can find cancer early at the most treatable stage.

Problems to watch for

People with PJS should watch for signs or symptoms that could signal cancer, such as:

  • Unexplained weight loss
  • Loss of appetite
  • Pain in the abdomen (belly)
  • Blood in the stool or changes in bowel habits
  • Aches, pains, lumps, or swelling that cannot be explained
  • Headaches or changes in vision,
  • Numbness, tingling or weakness that do not go away

It is important to seek medical help if anything unusual appears.

Maintain a healthy lifestyle

Habits that will help you maintain a healthy lifestyle include:

  • Eat a healthy diet with lots of fruits and vegetables.
  • Get regular exercise.
  • Avoid smoking or using tobacco products.
  • Avoid secondhand smoke.
  • Avoid excess sun exposure. Always wear sunscreen, a hat, and protective clothing when out in the sun.

Peutz-Jeghers syndrome care at St. Jude

The St. Jude Cancer Predisposition Program is dedicated to diagnosing and screening children with a genetic predisposition for cancer. Our program offers the best clinical care possible. We engage in cutting-edge research to gain more information about genetic disorders and cancer, and to improve the care and treatment for patients who are affected by these conditions. Learn more about the Division of Cancer Predisposition at St. Jude.

Our genetic counselors, clinicians, genetics nurse practitioners, and research assistants work together to provide patients with:

  • A complete health history
  • A record of cancer that happened over the past 3 generations (family tree or pedigree) to see how diseases were passed down
  • Physical exams to check for genetic disease
  • Confidential genetic counseling and testing
  • Cancer screenings for those with genetic disease to detect and treat cancer as soon as it occurs
  • Recommended cancer treatments and ways to reduce cancer risk
  • Genetic testing for immediate (1st degree) relatives

Related clinical trials

St. Jude offers clinical trials and cancer research studies for children, teens, and young adults who have cancers associated with PJS.

Learn more about clinical research at St. Jude.

GENETX: Assessing Gene Therapy Communication Needs

Study goal:

To learn more about participants beliefs, attitudes, and questions about gene therapy to help make web-based resources to share information. This could help patients make treatment decisions.


18 to 35 years old with rare genetic diseases

Published results
G4K: Genomes for Kids

Study goal:

The main goal of this study is to learn more about the reasons childhood tumors form and how to treat them better.

TBANK: Collecting, Banking, and Distributing Human Tissue Samples in St. Jude Biorepository

Study goal:

To provide a high-quality repository of tumor and normal samples to facilitate translational research performed by St Jude faculty and their collaborators

PG4KDS: Clinical Implementation of Pharmacogenetics

Study goal:

1) Test each patient for hundreds of gene variations that might be important for drug use. All of the gene test results will be in the research laboratory, but as time goes on, the study will evaluate scientific evidence and selectively move test results for a few genes into the medical record if the evidence strongly shows that the result can help in better prescribing of drugs for patients; 2) Estimate how often pharmacogenetic test results are moved from research tests into a patient’s medical record; 3) Use methods to choose which of these tests should be put in the medical record; 4) Use computer-based tools in the electronic medical record to help doctors use gene test results when prescribing drugs; 5) Share feelings and concerns of patients and their families about gene test information being put in their medical record.

SJFAMILY: Study of Cancer in Families

Study goal:

The main purpose of this trial is to learn about the genetic causes of cancer. 


Younger than 50 years old

A statue of children running and holding hands

Seeking treatment at St. Jude

Patients accepted to St. Jude must have a disease we treat and must be referred by a physician or other qualified medical professional. We accept most patients based on their ability to enroll in an open clinical trial.

How to seek treatment

Contact the Physician / Patient Referral Office

Call: 1-888-226-4343 (toll-free) or 901-595-4055 (local)  | Fax: 901-595-4011 | Email: | 24-hour pager: 1-800-349-4334


Learn more

If you have questions about the Genetic Predisposition Clinic and care for PJS, email our team at

Resources outside St. Jude