Medical Oncologist
CION Cancer Clinics
BAP1 tumour predisposition syndrome, explained plainly | CION Cancer Clinics
BAP1 tumour predisposition syndrome is an inherited condition that raises the risk of eye melanoma, mesothelioma, skin melanoma and kidney cancer. It is rare, and probably missed more often than it is found. This page explains what the syndrome is, who should be tested, how it is diagnosed, and why a BAP1 change in a tumour is not the same thing. At CION Cancer Clinics, our oncologists explain what a gene result means for you and your family, and plan the checks that follow.
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 BAP1 tumour predisposition syndrome?
- Who should be tested for BAP1 syndrome?
- How is the syndrome diagnosed?
- What do the words around BAP1 syndrome mean?
- Is a BAP1 change in a tumour the same as the syndrome?
- What this page cannot tell you
- What do families get wrong about BAP1 syndrome?
- Common questions about BAP1 tumour predisposition syndrome
The short answer
What is BAP1 tumour predisposition syndrome?
It is an inherited condition in which one copy of the BAP1 gene is faulty from birth, in every cell of the body. It raises the risk of a small group of cancers: melanoma of the eye, mesothelioma, melanoma of the skin and kidney cancer. Many people with it also develop small, harmless skin bumps that can act as an early clue.
Rare, and probably under-recognised
Only a limited number of affected families have been described in medical studies worldwide, and very few from India. That almost certainly reflects how rarely anyone looks for it, not how rare it truly is. Eye melanoma and mesothelioma are uncommon cancers, so a family pattern can go unnoticed for generations.
How it is passed on
The fault follows dominant inheritance. A parent who carries it has a one in two chance of passing it to each child, son or daughter alike. It does not skip generations, although the illness can appear to.
Why the diagnosis matters
Once the syndrome is known, carriers can have regular eye, skin and kidney checks aimed at finding cancer early. They can also cut their exposure to asbestos, which matters more for them than for most people.
Having the syndrome raises risk. It does not mean every cancer on the list will happen.When to suspect it
Who should be tested for BAP1 syndrome?
Testing is not for everyone with one of these cancers. It is considered when the pattern in a person or a family fits.
Eye melanoma with a family link
A melanoma inside the eye, especially at a younger age than usual, or alongside a relative with mesothelioma, kidney cancer or skin melanoma.
Unusual mesothelioma
Mesothelioma at a young age, in the lining of the abdomen, or in someone with little or no known asbestos exposure.
Several BAP1 cancers together
Two or more of the linked cancers in one person, or across close relatives on the same side of the family.
The linked cancers
- Melanoma of the eye
- Mesothelioma
- Melanoma of the skin
- Kidney cancer
A telling skin bump or tumour result
Several dome-shaped, skin-coloured bumps that a dermatologist suspects are BAP1-related. Or a tumour report showing BAP1 has been switched off, alongside a suggestive family history.
Not sure whether this applies to you?
Ask an oncologistStep by step
How is the syndrome diagnosed?
A clue in the family or the tumour
An oncologist, eye specialist or dermatologist notices a pattern. A pathologist may also report that BAP1 is missing from a tumour sample.
A genetic counselling appointment
The counsellor draws a family tree across both sides and checks whether the pattern fits well enough to test.
A blood test for the inherited fault
A blood or saliva sample is checked for a BAP1 fault present from birth. This is different from the tumour result, which cannot show inheritance on its own.
A result and a plan
A confirmed fault leads to a surveillance plan and an offer of testing to close relatives. A negative result is explained against the family history.
On your report
What do the words around BAP1 syndrome mean?
- BAP1
- A gene that acts as a brake on cell growth. When both copies stop working in a cell, that cell can grow out of control.
- Tumour predisposition syndrome
- An inherited condition that raises the chance of certain tumours. It is a risk, not a diagnosis of cancer.
- Uveal melanoma
- A melanoma that grows inside the eye, in the layer beneath the white. It cannot be seen in a mirror and is found on a dilated eye examination.
- Mesothelioma
- A cancer of the thin lining around the lungs or the abdomen. It is strongly linked to asbestos.
- BAP1-inactivated skin tumour
- A small, raised, usually harmless skin bump in which BAP1 has stopped working. Several of them can point to the syndrome.
- Germline
- Present in every cell from birth, and inheritable. The opposite is somatic, meaning a change found only inside a tumour.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
Is a BAP1 change in a tumour the same as the syndrome?
BAP1 change found only in the tumour
BAP1 fault found in blood
Arose in that one tumour during life
Present from birth in every cell
Cannot be passed to children
Each child has a one in two chance
Relatives do not need testing for it
Close relatives are offered testing
No lifelong checks because of it alone
Regular eye, skin and kidney checks
Being straight with you
What this page cannot tell you
It cannot tell you whether your family has the syndrome. That needs a counsellor who has seen your family tree and, usually, a blood test in the relative who had cancer. It also cannot interpret a BAP1 variant on a report you are holding. What your specific variant means is a question for the counsellor who ordered the test.
Who this does not apply to
Most people with mesothelioma, skin melanoma or kidney cancer do not have this syndrome. A single case in an older relative with heavy asbestos exposure rarely points to it. And a BAP1 change reported only in a tumour is not the syndrome until a blood test says so.
Where the evidence is thin
Most of what is known comes from families found because they had a lot of cancer. That may make the risks look higher than they are for a carrier found by chance. The best surveillance schedule is still debated, and expert groups differ on when checks should start.
Commonly believed
What do families get wrong about BAP1 syndrome?
"Mesothelioma only comes from asbestos, so it cannot be inherited."
Asbestos is the main cause for most people. In BAP1 families, mesothelioma can appear with much less exposure, or none that anyone can recall.
"Those skin bumps are cancer."
Almost always they are harmless. Their value is as a clue. A dermatologist may remove one to check it, or to watch for change, but most never cause trouble.
"My eyes are fine, because my vision is fine."
Melanoma inside the eye often causes no symptoms early on. Only a dilated examination by an eye specialist can look for it, which is why it is part of the plan.
"This only matters to people who worked with asbestos."
The eye, skin and kidney risks have nothing to do with asbestos. Every carrier benefits from checks, whatever their work history.
Questions we are asked
Common questions about BAP1 tumour predisposition syndrome
Is BAP1 syndrome common in India?
Nobody knows. Very few Indian families have been described, largely because testing is rarely done. Eye melanoma and mesothelioma are both uncommon, so the pattern is easy to miss. A family with these cancers deserves a counsellor's view, whatever the published numbers say.
Which checks do carriers usually have?
Usually a regular dilated eye examination, a full skin check by a dermatologist, and kidney imaging in adulthood. When each starts and how often it repeats differs between expert groups, so your counsellor sets the schedule for your family.
Should I avoid asbestos?
Yes, as far as you reasonably can. Asbestos-cement roofing sheets are still common in India. Avoid cutting, drilling or breaking them, and keep away from demolition dust. If your work involves asbestos, discuss it with your doctor and employer.
Should my children be tested?
It depends on your family and on when your counsellor thinks checks should begin. Because some BAP1 cancers can appear earlier than usual, the timing is discussed case by case. Your counsellor will explain the choice for your children.
My relative's tumour lost BAP1. Does our family have the syndrome?
Not necessarily. BAP1 is often switched off inside these tumours without any inherited fault. A blood test in that relative is what settles it. If they have died, ask whether a stored sample can be tested.
Does the syndrome change how a cancer is treated?
Treatment is mostly planned on the cancer itself. Some studies suggest mesothelioma in carriers may behave differently from other mesothelioma, but that evidence is still early. Your oncologist will explain whether it matters in your case.
Can the skin bumps be removed?
Yes, if a dermatologist thinks one needs checking under the microscope or is changing. Most can simply be watched. Photos taken at each skin check make changes easier to spot over time.
Where do we start in Hyderabad?
With a genetic counselling appointment, taking any reports and a list of who had which cancer and at what age. 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 Bookshelf) — BAP1 Tumor Predisposition Syndrome
- MedlinePlus Genetics — BAP1 tumor predisposition syndrome
- MedlinePlus Genetics — BAP1 gene
- National Cancer Institute — Genetic Testing for Inherited Cancer Susceptibility Syndromes
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
BAP1 mutation: which cancers and what riskThe linked cancers, one organ at a timeBAP1, mesothelioma and asbestosWhy asbestos matters more for carriersBAP1 skin lesions as an early clueWhat the skin bumps look like and why they matterSurveillance for BAP1 carriersThe eye, skin and kidney checks in detail
Talk to us
Does your family have eye melanoma or mesothelioma?
Tell us who was diagnosed and at what age. We will help you reach a genetic counsellor who can say whether BAP1 testing makes sense. One helpline serves every CION centre.