Your risk of developing a brain tumor is higher if you have a close relative with a history of brain cancer. Most brain tumors aren’t linked to a family history and have no clear cause.

Brain tumors can be cancerous or noncancerous. The World Health Organization recognizes more than 100 types of brain tumors.

Brain and other central nervous system (CNS) tumors are the second most common cancer in children under 14 (behind leukemia) and the most common cancer in adolescents ages 15–19. They’re the eighth most common cancer in adults over 40.

Brain tumors are caused by genetic changes inside your cells that cause them to replicate uncontrollably. Some genetic changes can be passed through your family and some are acquired throughout your life.

Only about 5%–10% of brain tumors occur in people with a family history.

Read on to learn more about the connection between genetics and brain tumors.

Brain tumors can be cancerous or noncancerous. Here’s a look at some of the most common types of brain tumors.

TypeSubtypePercentage of CNS tumors in the United StatesCancerous
MeningiomaBenign meningioma34.9%No
Pituitary tumorsPituitary adenoma16.5%No
GliomaGlioblastoma multiforme14.7%Yes
Nerve sheath tumorsAcoustic neuroma8.2%Usually not
Lymphomas and other blood cancersPrimary CNS lymphoma1.9%Yes
GliomaDiffuse astrocytoma1.9%Yes

As with other types of tumors, brain tumors develop when genetic changes cause cells to replicate uncontrollably. Brain tumors can be cancerous or noncancerous. Some noncancerous brain tumors can also cause difficulties if they compress healthy brain tissue.

Researchers have studied environmental and genetic factors related to brain tumors extensively, but they haven’t yet found a risk factor that accounts for a large portion of these tumors.

Inherited and acquired genetic changes

Genetic changes can be inherited or acquired. Inherited genes are passed down to you by your parents. Cancers associated with inherited genes tend to cluster in families. Noninherited genetic changes develop throughout your life.

Most brain tumors don’t run in families. According to the American Association of Neurological Surgeons, gliomas are the most common type of brain tumor. Only about 5% of gliomas are linked to a family history.

In a 2019 study, researchers found that the risk of developing a brain tumor was about 20% higher in people with a family history of cancer and about double in a person with two relatives who had cancer.

Genetic risk factors for brain tumors

Glioma is responsible for the majority of brain tumor deaths. Most of the genetic research on brain tumors has focused on glioma.

Researchers have identified at least 25 gene mutations associated with an increased risk of developing glioma and its subtypes. Some of these include:

GeneCancer type
MSH6Medulloblastoma, glioma, glioblastoma
MSH2Medulloblastoma, glioma, glioblastoma
C2orf80Lower grade glioma
LRIG1Lower grade glioma

Radiation exposure is the most well-documented risk factor for brain tumors. Children seem to be more sensitive to radiation than adults, and the risk seems to increase with higher doses.

Studies have found an association between brain tumors and radiation delivered through:

  • prior therapeutic radiation
  • bomb or nuclear reaction explosions
  • occupational or environmental exposure

Other potential risk factors for brain tumors that have less research to support them include:

  • Viral infections: Several types of viral infections such as human papillomavirus (HPV) and cytomegalovirus infections have been suggested to be linked to brain tumors. Research linking viral infections to brain tumors has been largely mixed.
  • Birth weight: There’s a reasonable amount of evidence, supported by three large reviews, that brain and CNS tumors are associated with a higher birth weight.
  • Developmental issues in the fetus: Birth irregularities are a risk factor for childhood cancer in general. About 7% of childhood brain and CNS tumors are associated with developmental issues in the fetus.
  • Taller height: Taller height has been linked to an increased risk of brain tumors, with an increased risk of about 20% for every 10 centimeters (3.9 inches) of height.
  • Socioeconomic positions: Increasing evidence suggests that a higher socioeconomic position is linked to a higher risk of brain tumors, although the exact reason why isn’t clear.
  • Increasing age: Adults become more likely to develop brain tumors with increasing age.
  • Biological sex: Cancerous tumors occur much more often in males and noncancerous occur more frequently in females.
  • Race: Countries with higher percentages of people with European ancestry have the highest rates of brain tumors.
  • Some medications: Some medications such as statins and nonsteroidal anti-inflammatory medications (NSAIDs) have been linked with a decreased risk of brain tumors.
  • Respiratory allergies: The presence of respiratory allergies in adults has been linked with a lower risk of developing brain cancer.

Symptoms of brain cancer can vary depending on where the tumor develops and how big it is. Tumors often don’t cause symptoms in the early stages, and symptoms may get worse slowly over time.

Common symptoms include:

It’s important to seek medical attention if you have any of these symptoms with no known cause. It’s especially important to see a doctor if you have a headache that’s getting progressively worse or feels different than headaches you’ve had in the past.

Learn more about the signs and symptoms of brain tumors.

The World Health Organization recognizes more than 100 types of brain tumors. A small percentage of brain tumors are associated with a family history, but most aren’t.

Brain tumors develop when genetic changes in your cells cause them to replicate uncontrollably. A combination of inherited gene changes and gene changes acquired throughout your life play a role in their development.

Radiation exposure is the most well-established risk factor.