Medical Oncologist
CION Cancer Clinics
Turcot syndrome: bowel polyps, brain tumours and what the link means | CION Cancer Clinics
Turcot syndrome is an older name for families in which bowel polyps and brain tumours occur together. Doctors now trace it to one of two gene conditions: FAP, where the brain tumour is usually a medulloblastoma, or a mismatch repair condition, where it is usually a glioma. The brain tumour risk is raised but still uncommon. This page explains what the name means today and what to watch for. 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 Turcot syndrome?
- Which gene conditions sit behind Turcot syndrome?
- What happens once a family is found to have it?
- The words you will meet, in plain language
- The two types compared
- What this page cannot tell you
- Four things families tell us, and what is actually true
- Common questions about Turcot syndrome
The short answer
What is Turcot syndrome?
Turcot syndrome is a name for bowel polyps and a brain tumour occurring together, in one person or one family. It is not a separate gene condition. Doctors now trace almost every case to FAP, caused by a fault in the APC gene, or to a mismatch repair condition such as Lynch syndrome. Which one it is changes the kind of brain tumour, the checks and the advice for relatives.
Why the old name causes confusion
Families are sometimes told they have Turcot syndrome without being told which gene is behind it. That matters, because the two versions behave differently. If a report or discharge letter says Turcot, ask which gene was found. The answer points you to the right plan.
How rare it is
Brain tumours in FAP are uncommon. The risk is much higher than in the general population, but most people with FAP never develop one. The bowel remains the main concern. Brain tumour risk is a smaller, separate part of the picture, and studies of it are small because it is so rare.
For most families with FAP, knowing the warning signs of a brain tumour is the right level of attention.Two conditions, one name
Which gene conditions sit behind Turcot syndrome?
The old name covers two quite different situations. Your counsellor will tell you which one applies to your family.
The FAP type
Caused by a fault in the APC gene. The brain tumour, when one occurs, is usually a medulloblastoma, a tumour at the back of the brain that tends to appear in childhood or the teenage years. The bowel has the many polyps typical of FAP.
The mismatch repair type
Caused by faults in the genes that correct copying errors in DNA, the same genes involved in Lynch syndrome. The brain tumour is usually a glioma. When a child inherits a fault from both parents, brain and bowel tumours can appear in early childhood.
Signs to report
These usually have ordinary causes. In a family with Turcot syndrome they deserve a prompt check with a doctor who knows the gene fault.
- Headaches worse in the morning, or with vomiting
- Unsteady walking or new clumsiness
- Double vision, or a squint that appears suddenly
- A seizure, or a change in behaviour or schoolwork
What is not a warning sign
Ordinary tension headaches, a one-off dizzy spell and headaches around exams are common in teenagers. They are usually nothing to do with the gene fault. The pattern and how long it lasts matter more than any single episode.
Not sure whether this applies to you?
Ask an oncologistStep by step
What happens once a family is found to have it?
Identify the gene
The person who has had a brain tumour or polyps is tested first, if possible. This tells the family whether the fault is in APC or in a mismatch repair gene, and that shapes everything after.
Test relatives for that fault
Once the exact fault is known, relatives on that side can be tested for it. Those who do not carry it need no extra checks beyond what anyone their age would have.
Set the bowel plan
Carriers start colonoscopy at the age their condition calls for. For FAP this usually means the early teens. For a mismatch repair fault it is later, unless a child has inherited faults from both parents.
Agree the brain plan
For the FAP type, most guidelines rely on knowing the symptoms rather than routine brain scans. Children with faults from both parents are usually offered regular brain MRI from early childhood.
On your report
The words you will meet, in plain language
- Medulloblastoma
- A brain tumour at the back of the brain, in the part that controls balance. Most often seen in children.
- Glioma
- A tumour that grows from the supporting cells of the brain. Gliomas range from slow-growing to fast-growing.
- APC gene
- The gene behind FAP. A fault in it makes the bowel grow many polyps.
- Mismatch repair genes
- Genes that fix copying mistakes when cells divide. Faults in them cause Lynch syndrome.
- CMMRD
- Constitutional mismatch repair deficiency. A rare childhood condition in which a mismatch repair fault is inherited from both parents.
- WNT-activated medulloblastoma
- A type of medulloblastoma defined by how it grows. It can sometimes point to an inherited APC fault.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
The two types compared
APC type (FAP)
Mismatch repair type
Brain tumour usually a medulloblastoma
Brain tumour usually a glioma
Many bowel polyps, often hundreds
Fewer polyps, except in children with CMMRD
Brain watched mainly through symptoms
Brain MRI offered to children with CMMRD
Inherited from one parent
From one parent, or from both in CMMRD
Being straight with you
What this page cannot tell you
It cannot tell you which type your family has. That comes from genetic testing, and from a counsellor who has looked at your family tree and the reports of anyone who has had a tumour. If a letter only says Turcot syndrome, go back and ask which gene.
It cannot tell you what a symptom means
Headaches and clumsiness have many ordinary causes. A doctor who knows about the family's gene fault needs to examine the person and decide whether a scan is needed. What your specific variant means is a question for the counsellor who ordered the test.
Who this does not apply to
Most people with FAP never develop a brain tumour, and most people with a brain tumour have no inherited bowel condition. Changes found only in a tumour sample, and not in the blood, are a different question covered under targeted therapy. For families travelling from the districts, the first counselling visit can often cover the bowel and brain questions together.
If a child in the family has had a medulloblastoma, ask whether the tumour type points towards inherited testing.Commonly believed
Four things families tell us, and what is actually true
"Turcot syndrome is its own separate disease."
It is an older name. Nearly every case is now traced to FAP or to a mismatch repair condition, and the plan follows whichever gene is found.
"Everyone with FAP needs regular brain scans."
For the FAP type, routine brain scans are not usually recommended, because the tumour is rare and a scan in a well child seldom finds one. Knowing the warning signs and reporting them promptly is the usual approach.
"A headache in a child with FAP means a brain tumour."
Headaches are very common in children and teenagers and almost always have ordinary causes. What matters is a pattern: morning headaches with vomiting, unsteady walking or changes in vision. Those should be checked promptly.
"After a brain tumour, the bowel matters less."
In FAP the bowel still carries the larger lifelong risk. Colonoscopy and, later, preventive bowel surgery remain part of the plan alongside any care for the brain tumour.
Questions we are asked
Common questions about Turcot syndrome
Is Turcot syndrome the same as FAP?
Not exactly. Some families labelled Turcot have FAP with an added brain tumour, usually a medulloblastoma. Others have a mismatch repair condition, where the brain tumour is usually a glioma. Genetic testing tells you which, and that decides the plan.
How likely is a brain tumour in FAP?
Uncommon. The risk is much higher than for other people, but most people with FAP never have one. Your counsellor can explain what is known for your family's specific fault, while being honest that the studies behind it are small.
At what age do these brain tumours appear?
In the FAP type, medulloblastoma tends to appear in childhood or the teenage years. In children with faults from both parents, brain tumours can appear in early childhood. In adults with one mismatch repair fault, gliomas can arise later in life.
Should my child with FAP have a brain MRI?
Not routinely, in most guidelines, because the tumour is uncommon and a scan in a well child rarely finds one. If your child has warning symptoms, a scan is sensible. Ask your team whether anything in your family changes that advice.
My child had a medulloblastoma. Should we test for FAP?
Sometimes. If the tumour is of the WNT-activated type and lacks the usual tumour-only change, doctors now often recommend testing the blood for an inherited APC fault. The treating oncologist and a genetic counsellor can advise on your child's report.
Is the brain tumour treated differently in FAP?
The brain tumour itself is treated much as it would be in any child, by a paediatric brain tumour team. What changes is the long-term plan, because the child will also need bowel checks and, later, preventive bowel surgery.
Why do cousin marriages matter here?
For the mismatch repair type, a child who inherits a fault from both parents can develop CMMRD, with brain and bowel tumours in childhood. This is more likely when parents are related by blood. A counsellor can advise couples in the family before a pregnancy.
Where do we start?
Gather every report: colonoscopy, brain scan, pathology and any genetic result. Take them to a genetic counsellor or your oncologist. Call the CION helpline if you are unsure who to see, and someone will point you to the right clinic.
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) — APC-Associated Polyposis Conditions
- MedlinePlus Genetics — Familial adenomatous polyposis
- MedlinePlus Genetics — Constitutional mismatch repair deficiency syndrome
- National Cancer Institute — Genetics of Colorectal Cancer (PDQ)
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
Familial adenomatous polyposis explainedThe bowel condition at the centre of the FAP typeGardner syndrome featuresThe other old name FAP families are givenWhen screening should start in an FAP familyWhen colonoscopy begins for carrier childrenTelling children they may have FAPHow to explain the checks to a young child
Talk to us
Told your family has Turcot syndrome and unsure what it means?
Tell us what the reports say and who in the family has been affected. We will help you reach a counsellor who can explain which gene is involved and what checks make sense. One helpline serves every CION centre.