About Hereditary Brain Aneurysms

What is a hereditary brain aneurysm?

Finding out that you or someone you love may be at risk for a brain aneurysm can feel overwhelming. Whether it’s a recent diagnosis or a family history that’s raised concern, we're here to offer clear, straightforward information—so you can feel more informed, more in control, and better supported every step of the way. Discovering that you or a loved one has a brain aneurysm, or learning about a familial risk, can be overwhelming. This page provides clear and concise information to help you navigate this complex topic.

​​

Who is at risk of a brain aneurysm?

​

​​Aneurysms may develop due to a combination of genetic and lifestyle factors:

• High blood pressure (hypertension)

• Smoking

• Family history of brain aneurysms (hereditary aneurysms)

• Age over 40

• Female (women are more prone)

• Connective tissue disorders (e.g., Ehlers-Danlos syndrome, polycystic kidney disease)

• Drug use (especially stimulants like cocaine)

• Heavy alcohol consumption

• Head injury or trauma​

​​

Certain lifestyle factors, like smoking, a poor diet, not getting enough sleep, or feeling constantly stressed, can gently increase the risk of developing an aneurysm over time. Making small, positive changes in these areas can help support your overall brain and heart health.

​

It’s important to know that many people live with a brain aneurysm for years without any symptoms, some people never know they have one. They’re often found by accident during scans or tests for something completely unrelated and never cause any problems.

​

Are brain aneurysms hereditary?

​

Most brain aneurysms happen at random, called sporadic aneurysms, with generally only a single case in a family. Occasionally, however, an individual with a brain aneurysm will have other close family members who have also had brain aneurysms. Research indicates that 1 in 8 people who have an aneurysm has the familial or hereditary condition.

​

When two or more first-degree relatives (parent, child, or sibling) have proven brain aneurysms, people can be given the diagnosis of ‘familial aneurysm syndrome’, and close family members may be referred for further investigations and screenings. In the medical community, these are often referred to as familial aneurysms. 

​

Genetic conditions linked to aneurysms

​

Some genetic disorders can predispose individuals to aneurysms, including:

• Autosomal Dominant Polycystic Kidney Disease (ADPKD): A genetic disorder causing numerous cysts in the kidneys.

• Ehlers-Danlos Syndrome (Types II and IV): Connective tissue disorders that can weaken blood vessel walls.

• Marfan Syndrome: A disorder affecting connective tissue, potentially leading to vascular complications.

​​

I think I may be at hereditary risk? How can I get a genetic test for brain aneurysms?

​

It's a great question - there is no genetic test as yet unfortunately, there are research projects underway, like the ROAR-DNA Study that will hopefully get us closer to a genetic test. Until then screening is done through brain scans via a MRA (Magnetic Resonance Angiography) or MRI (Magnetic Resonance Imaging) scan.

​

Who can get screened for hereditary brain aneurysms?

​According to the NICE guidelines, hereditary (familial) aneurysms occur when two or more first-degree relatives ( (parents, brothers, and sisters) have had a brain haemorrhage from an aneurysm or have diagnosed unruptured aneurysm/s. In these cases, screening may be offered through an MRA  (Magnetic Resonance Angiography or Angiogram) or MRI (Magnetic Resonance Imaging) brain scan to check for possible aneurysms too.

​

These are however just guidelines and every Neuro-centre and team have their own interpretation. Also, every person and family is different and screening is a very personal choice, so there is no one size fits all answer unfortunately.

​

Even if you don’t meet these criteria but are worried about a family pattern, we would usually advise you still to talk to your GP about your family history and worries. They can then advise on the next steps and access to NHS screening. You may also be referred to a genetic counsellor to discuss your family history and decide whether screening is right. 

​

If you have been diagnosed with a brain aneurysm and are worried about your family then your neurosurgeon or neuro vascular specialist will be able to offer advice tailored to your families personal situation and history and guide you on appropriate next steps.

​

If you are still worried but not able to access screening, you are also entitled to a second opinion and of course there are private screening options, but we would always advise for you to work with your current medical teams where possible as they understand your history and family story.

We have a few guides that might be able to help you:

• Understanding Familial (Hereditary) Brain Aneurysms

• The Science & Genetics Behind Familial Aneurysm Syndrome

• An Introduction to Genetic Counsellors

​​​