Medical Oncologist
CION Cancer Clinics
Peutz-Jeghers syndrome: what it is and what it means for a family | CION Cancer Clinics
Peutz-Jeghers syndrome is a rare inherited condition caused by a fault in the STK11 gene. It causes dark freckle-like spots around the mouth and on the fingers, polyps in the gut that can bleed or block the bowel, and a raised chance of several cancers in adult life. This page explains how it is recognised, how it is passed on, and why checks start in childhood. At CION Cancer Clinics, our oncologists plan screening and care for families with an inherited cancer syndrome, explained in plain words.
NG
Medically reviewed by Dr. Naresh GunduConsultant Medical Oncologist · MBBS, DNB (Internal Medicine), DM (Medical Oncology, AIIMS) · last reviewed September 2026, next review due September 2027
17+specialists on panel
15,000+patients treated
35+centres across Telangana & AP
4.8★ / 800+Google rating
On this page
- What is Peutz-Jeghers syndrome?
- What are the signs of Peutz-Jeghers syndrome?
- How does care change from childhood to adult life?
- The words you will meet, in plain language
- What a genetic result changes for the family
- What this page cannot tell you
- Four things families tell us, and what is actually true
- Common questions about Peutz-Jeghers syndrome
The short answer
What is Peutz-Jeghers syndrome?
Peutz-Jeghers syndrome is a rare inherited condition caused by a fault in a gene called STK11. It causes dark spots around the mouth and on the fingers, polyps in the gut that can bleed or block the bowel, and a raised chance of several cancers in adult life.
Why it usually shows itself in childhood
The dark spots often appear in the first few years of life. The gut polyps grow through childhood and the teens, and the first sign is often a sudden bout of severe tummy pain or a low haemoglobin from slow bleeding. Many families only hear the name after a child has had an emergency operation on the bowel.
Why a name on the report matters
Once the syndrome is recognised, the gut can be checked on a planned schedule and large polyps removed before they cause trouble. Adults can be screened for the cancers the condition makes more likely. Relatives can be tested for the exact gene fault, and those who do not carry it can stop worrying.
Peutz-Jeghers syndrome is not a cancer. It is a condition that raises the chance of cancer and needs regular checks.How it shows itself
What are the signs of Peutz-Jeghers syndrome?
Doctors look for three things, and a genetic test to confirm them.
Dark spots on the skin
Small flat spots, dark brown to blue-grey, on and around the lips, inside the cheeks, and on the fingers and toes. They are harmless and never turn into cancer.
Usually looks like
- Appear in early childhood
- Fade on the lips and skin in adult life
- Spots inside the mouth tend to stay
Polyps in the gut
Growths of a particular kind, mostly in the small bowel, but also in the stomach and large bowel. They are not cancer, but large ones can bleed slowly or cause the bowel to fold in on itself.
A raised cancer risk
Over a lifetime, the chance of cancer is substantially higher than in the general population. The bowel, stomach, pancreas and breast are the main organs involved, along with the ovaries, cervix and testicles.
How it is confirmed
A doctor can diagnose it from the polyps, the spots and the family history. A blood test for STK11 confirms it in most people and gives relatives an exact fault to test for.
Not sure whether this applies to you?
Ask an oncologistAcross a lifetime
How does care change from childhood to adult life?
-
Early childhood: recognising it
The spots, a family history, or an episode of severe tummy pain lead to the diagnosis. Children of an affected parent are usually tested young, because checks start in childhood.
-
Middle childhood: the first gut checks
A camera test of the stomach and bowel, and a look at the small bowel by capsule or MRI, set the baseline. Boys also have their testicles examined at routine visits.
-
The teens: keeping polyps small
Small-bowel checks are repeated every few years. Larger polyps are removed on a planned day, which lowers the chance of an emergency operation.
-
Adult life: adding cancer screening
Gut checks continue. Breast screening for women starts earlier than usual, and gynaecological checks and, at some centres, pancreas imaging are added.
-
Throughout: one coordinating doctor
Several specialists are involved. Having one doctor who holds the whole plan together stops checks being missed or repeated.
On your report
The words you will meet, in plain language
- STK11
- The gene behind the syndrome. It normally helps control how fast cells grow. Older reports may call it LKB1.
- Hamartomatous polyp
- The type of polyp seen in this syndrome. It is an overgrowth of normal gut tissue, not a cancer.
- Pigmentation
- The dark spots on the lips, mouth and fingers. Doctors may write mucocutaneous pigmentation.
- Intussusception
- When a section of bowel slides into the next section, like a telescope, often pulled by a large polyp. It needs emergency care.
- Capsule endoscopy
- Swallowing a pill-sized camera that photographs the small bowel as it passes through.
- Germline
- Present in every cell from birth, and therefore something that can be passed on to children.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
What a genetic result changes for the family
An STK11 fault is found
No fault is found
Relatives can be tested for that exact fault
Relatives are advised using the family history instead
Children who test negative can skip years of checks
Children of an affected parent may still need checks
Testing in pregnancy or through IVF becomes possible
These options are not available
The diagnosis is settled
The doctor may still diagnose it from the signs
Being straight with you
What this page cannot tell you
It cannot tell you whether you or your child has the syndrome. That needs a doctor to look at the spots, the polyps and the family history, and usually a genetic test. Nor can it tell you what your own cancer risk is, because published figures vary widely from study to study.
It cannot read a genetic report
What your specific variant means is a question for the counsellor who ordered the test. This page is about inherited STK11 faults. An STK11 change found only in a tumour sample answers a different question about that cancer, and is covered in our targeted therapy pages.
Who this does not apply to
Most people with freckles on the lips do not have this syndrome. Most people with a single gut polyp do not either, and most children with tummy pain do not. Testing is worth discussing when the spots and polyps appear together, or when a close relative is affected.
Peutz-Jeghers syndrome is rare, so studies are small. Surveillance plans are based on expert agreement as much as on large trials.Commonly believed
Four things families tell us, and what is actually true
"The spots on the lips are the dangerous part."
The spots are harmless and never turn into cancer. They matter only as a clue that leads to the diagnosis. Some people have them lightened for appearance, which is safe.
"The polyps were removed, so it is over."
New polyps keep forming throughout life, because the gene fault is still there. Removing them is part of ongoing care, not an end point.
"Nobody else in the family has it, so the children are safe."
Some people are the first in their family to have the fault, and they can pass it to each child with a one in two chance. Children still need to be offered testing.
"Having the syndrome means cancer is certain."
The risk is high, but it is not a certainty. Regular checks are designed to find problems early, when they are easier to treat.
Questions we are asked
Common questions about Peutz-Jeghers syndrome
How is Peutz-Jeghers syndrome inherited?
A parent with the syndrome has a one in two chance of passing it to each child, whether a son or a daughter. It can also arise new in a person with no family history. A counsellor can explain what this means for your own family.
At what age should a child be tested?
Usually in childhood, well before the teens, because gut checks start young and bowel blockages can happen early. A negative test means the child needs no special checks. Your counsellor will advise on timing for your family.
Is the syndrome dangerous in childhood?
The main risk in childhood is a bowel blockage from a large polyp, which is an emergency. Slow bleeding can also cause a low haemoglobin and tiredness. Planned checks and removal of large polyps greatly reduce these risks.
Can the dark spots be removed?
Yes, for appearance, often with laser treatment by a skin specialist. Removing them does not change the gut polyps or the cancer risk. They also tend to fade on the lips in adult life on their own.
Which doctors will we need to see?
Usually a gastroenterologist, a genetic counsellor and, in adult life, doctors who screen the breast, pancreas and reproductive organs. Children are seen by a paediatric gastroenterologist. It helps to have one doctor who coordinates everything.
Does diet or lifestyle affect the polyps?
No diet has been shown to stop the polyps forming. A healthy weight, not smoking and limiting alcohol are sensible for anyone with a raised cancer risk. They do not replace the planned checks.
Is the genetic test available in Hyderabad?
Yes. STK11 testing is done on a blood sample, either alone or as part of a panel of genes. Your counsellor will tell you how long results take. Testing the person who already has signs first gives the clearest answer for the rest of the family.
Where do we start?
Gather any endoscopy or polyp reports, operation notes and photos of the spots, and note who in the family has had polyps or cancer. Call the CION helpline and we will help you reach a genetic counsellor and a gastroenterologist.
Your Specialists
Meet CION's oncologists. Bring your family history or genetic report to them.
Our medical oncologists see people with a strong family history of cancer, arrange genetic counselling and testing where it fits, and plan the checks that follow.
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
Sources
- GeneReviews (NCBI Bookshelf) — Peutz-Jeghers Syndrome
- MedlinePlus Genetics — Peutz-Jeghers syndrome
- National Cancer Institute — Genetics of Colorectal Cancer (PDQ) – Health Professional Version
- British Society of Gastroenterology / ACPGBI / UKCGG (Gut) — Guidelines for the management of hereditary colorectal cancer
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
Keep reading
Related pages
The pigmented spots: what they meanWhy the spots appear, fade, and never turn into cancerBowel blockage and intussusception in childrenThe emergency every parent should recogniseCancer risks across organs in Peutz-JeghersWhich organs are watched in adult life, and howSmall bowel surveillance and balloon enteroscopyHow large polyps are found and removed on a planned day
Talk to us
Wondering whether these signs point to Peutz-Jeghers?
Tell us about the spots, any polyps and who in the family has been affected. We will help you reach a genetic counsellor and a gastroenterologist who can look at it properly. One helpline serves every CION centre.