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CION Cancer Clinics
NF2, SMARCB1 and LZTR1: which tumours, and what cancer risk | CION Cancer Clinics
Faults in NF2, SMARCB1 and LZTR1 mostly cause benign tumours on nerves and on the lining of the brain and spine. They rarely become cancer. The harm comes from where they grow: hearing, balance, the spinal cord or lasting pain. One kind of SMARCB1 fault is different and carries a real childhood cancer risk. This page explains which gene raises which risk, and what it means for you. At CION Cancer Clinics, our oncologists explain what a gene result means for you and your family, and plan the checks that follow.
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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
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On this page
- Do NF2 and the schwannomatosis genes cause cancer?
- What each gene raises the risk of
- How does a gene fault turn into a schwannoma?
- The words you will meet, in plain language
- What is common, and what is rare?
- What this page cannot tell you
- Four things families tell us, and what is true
- Common questions about NF2 and schwannomatosis risks
The short answer
Do NF2 and the schwannomatosis genes cause cancer?
Mostly, no. Faults in NF2, SMARCB1 and LZTR1 cause tumours on nerves and on the lining of the brain and spine. Almost all of these tumours are benign, meaning they grow slowly and do not spread. The harm they do comes from where they grow.
Why benign does not mean harmless
A benign tumour on the nerve for hearing can take away hearing. One on the spinal cord can cause weakness. One on a body nerve can cause lasting pain. So these conditions need regular scans and careful decisions, even though cancer is rarely the issue.
Where genuine cancer risk sits
The clearest cancer risk belongs to one kind of SMARCB1 fault. It can cause a fast-growing childhood cancer called a rhabdoid tumour, usually in infants. This is a different pattern from SMARCB1 schwannomatosis in adults, and a report should say which one is meant. A benign tumour turning into cancer is rare in all of these conditions.
NF2 is now often called NF2-related schwannomatosis. Older reports and websites still use the name neurofibromatosis type 2.Gene by gene
What each gene raises the risk of
Three genes, several patterns. Your report tells you which one applies.
NF2
The hallmark is a benign tumour on the hearing and balance nerve on both sides of the head.
Also common
- Meningiomas on the lining of the brain or spine
- Tumours inside the spinal cord
- Schwannomas on other nerves and in the skin
- Clouding of the lens of the eye at a young age
SMARCB1 schwannomatosis
Several benign schwannomas on the nerves of the spine, arms and legs. Pain is usually the main problem. Some people also develop meningiomas.
SMARCB1 rhabdoid tumour risk
A different kind of SMARCB1 fault raises the chance of a rhabdoid tumour in the brain or kidney in early childhood. This one is a true cancer, and children are watched closely.
LZTR1
Benign schwannomas, mostly on body nerves, with pain as the main symptom. Some LZTR1 changes are linked to a separate developmental condition, Noonan syndrome, and are read differently.
Not sure whether this applies to you?
Ask an oncologistHow a tumour forms
How does a gene fault turn into a schwannoma?
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A faulty copy is present from birth
Every cell carries one faulty copy of NF2, SMARCB1 or LZTR1, and one working copy.
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A nerve-wrapping cell loses its working copy
During life, a single cell around a nerve loses the remaining working copy by chance.
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In schwannomatosis, NF2 is lost in that cell too
These genes sit close together on the same chromosome. When one is lost, NF2 often goes with it, and the cell loses a key brake.
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The cell grows into a slow tumour
It forms a schwannoma, which grows slowly and does not spread.
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Harm comes from pressure
As it grows, it presses on the nerve it sits on. That is what causes hearing loss, weakness or pain.
On your report
The words you will meet, in plain language
- Schwannoma
- A benign tumour of the cells that wrap around a nerve.
- Vestibular schwannoma
- A schwannoma on the nerve for hearing and balance. Older reports call it an acoustic neuroma.
- Meningioma
- A usually benign tumour of the lining around the brain or spinal cord.
- Ependymoma
- A tumour inside the spinal cord. In NF2 these usually grow very slowly.
- Benign
- Does not spread to other parts of the body. It can still cause harm by pressing on nearby tissue.
- Rhabdoid tumour
- A fast-growing childhood cancer linked to one kind of SMARCB1 fault.
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Side by side
What is common, and what is rare?
Common, benign but can cause harm
Rare, and treated as cancer
Tumours on the hearing and balance nerves in NF2
A benign nerve tumour turning malignant
Meningiomas on the lining of the brain
A later cancer in an area treated with radiotherapy
Painful schwannomas on body nerves
Rhabdoid tumours in infants with certain SMARCB1 faults
Slow tumours inside the spinal cord
Common cancers, which these genes are not known to raise
Being straight with you
What this page cannot tell you
It cannot put a number on your own risk. These conditions are rare, and studies of them are small. How many tumours a person develops, and how fast, varies widely, even within one family.
It cannot interpret your result
What your specific variant means is a question for the counsellor who ordered the test. This matters most for SMARCB1, where the kind of change decides whether the concern is adult schwannomas or a childhood cancer.
Who this does not apply to
A single schwannoma in an older adult, on one side only, is usually a one-off and does not point to an inherited fault. Most people with one such tumour do not need a genetic test. An NF2 or SMARCB1 change found only in a tumour sample is also a different finding, covered on our targeted therapy pages.
If you have a report and cannot tell which condition it describes, ask the doctor who ordered it before reading further.Commonly believed
Four things families tell us, and what is true
"A brain tumour means cancer."
The tumours in NF2 and schwannomatosis are almost always benign. They are treated seriously because of where they grow, not because they spread.
"Radiotherapy is safer because it avoids surgery."
In NF2, radiotherapy is used with care. It carries a small chance of a later cancer in the treated area, and it can make any later surgery harder.
"Schwannomatosis is just a milder form of NF2."
They are caused by different genes. Schwannomatosis mainly causes pain from body nerves, and usually spares hearing.
"Any SMARCB1 result means my baby will get cancer."
It depends on the kind of fault. The type seen in adult schwannomatosis families is usually different. Your counsellor will say which one your family has.
Questions we are asked
Common questions about NF2 and schwannomatosis risks
Is NF2 a cancer?
No. NF2 is a genetic condition that causes benign tumours on nerves and on the lining of the brain and spine. These tumours do not spread. They can still cause serious problems, such as hearing loss, which is why people with NF2 have regular scans.
Can a schwannoma turn into cancer?
It is rare. Most schwannomas stay benign for life. A tumour that grows unusually fast or starts causing new, severe pain should be reviewed promptly, but most such changes still turn out to be benign.
Why is radiotherapy used cautiously in NF2?
Radiation to a benign tumour carries a small chance of causing a later cancer in the same area. People with NF2 may also live many decades with their tumours. Doctors weigh this carefully against surgery and drug treatment for each tumour.
Does NF2 raise the risk of breast or bowel cancer?
These genes are not known to raise the risk of common cancers such as breast, bowel or lung cancer. Follow the ordinary screening advised for your age. Your NF2 reviews focus on the brain, spine and nerves.
What is the rhabdoid tumour risk with SMARCB1?
Some SMARCB1 faults cause a fast-growing cancer in infants and young children, in the brain or kidney. Babies in these families are watched with regular scans in early childhood. The counsellor will tell you whether your family's change is this kind.
Can these conditions be passed on?
Yes. Each child of someone who carries the fault in every cell has a one in two chance of inheriting it. Many people with NF2 are the first in their family, and some carry it in only part of the body, which changes the chance for children.
Are there drug treatments for these tumours?
For NF2, a drug that cuts off a tumour's blood supply is used in some centres to slow growing hearing-nerve tumours and protect hearing. It does not remove the tumours. Drug options for schwannomatosis pain are mainly pain-relief medicines.
Who treats NF2 and schwannomatosis?
Care is usually shared between a neurosurgeon, an ear specialist, a neurologist and a genetic counsellor. Counselling can be given in Telugu. Call the CION helpline if you are not sure who to see first.
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)
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Sources
- GeneReviews (NCBI Bookshelf) — NF2-Related Schwannomatosis
- MedlinePlus Genetics — Schwannomatosis
- MedlinePlus Genetics — SMARCB1 gene
- NHS — Neurofibromatosis type 2 (NF2)
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
NF2 and the schwannomatosis genes: what they doWhat these genes normally do in a nerve cellSchwannomatosis vs NF2How doctors tell the two conditions apartHearing surveillance and NF2How hearing is watched and protectedSurveillance for NF2 and schwannomatosis carriersWhich scans and checks happen, and when
Talk to us
Has a report named NF2, SMARCB1 or LZTR1?
Tell us what the report says and who ordered it. We will help you reach a counsellor who can explain which condition it describes and what care comes next. One helpline serves every CION centre.