Familial aneurysm

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Special aneurysm consultation at the Inselspital

At the Inselspital, the aneurysm consultation hours of Prof. Andreas Raabe or Dr. David Bervini offer the opportunity for a detailed consultation. The clinical picture of the aneurysm, from its development, a possible rupture to the best treatment for our patients, is a research focus of our clinic. In this article, you will find answers to the most frequently asked questions:

We will be happy to answer further questions in our special consultation. Please ask your attending physician to refer you or contact us directly.

Are cerebral artery aneurysms hereditary?

Aneurysms in cerebral arteries are often incidental findings and harmless in many cases. However, they can also burst and then cause cerebral hemorrhage. For relatives of aneurysm patients, the question often arises whether aneurysms are hereditary? The answer is yes. However, only a small proportion of aneurysms show a genetic disposition and thus a familial clustering.

While the incidence of an aneurysm in the general population is about 2%, the risk of an aneurysm increases to 4% if a first-degree family member (father, mother, children, siblings) already has an aneurysm, and to 8% if 2 first-degree relatives have aneurysms.

In patients with familial cystic kidneys, 10% also have an intracranial aneurysm, and here too there is an increase in aneurysm families. Second- or third-degree relatives probably also have an increased risk of aneurysm, and some of the results in scientific studies also extend to more distant relatives.

Is aneurysm screening useful for family members?

It is a familial aneurysm disease if two or more first-degree relatives have an aneurysm. If desired, first-degree relatives can be specifically screened for aneurysms using a non-invasive method such as magnetic resonance angiography (MR angiography). Not only are aneurysms more common in affected families, the overall risk is also increased. Familial aneurysms have a higher risk of rupture, and family members have a younger age when rupture occurs and a higher death rate from rupture *. Screening of the sibling is also warranted in identical twins with aneurysm, as well as in patients with autosomal dominant polycystic kidney disease.

A large study found new, important evidence of the risk of rupture in familial aneurysms *. Aneurysms were diagnosed in 20.6% of first-degree relatives, who, however, belonged to a special risk group – all were smokers or suffered from high blood pressure. Aneurysms ruptured with a frequency of 1.2% per year, including so-called small aneurysms (< 7 mm) of the anterior circulation.


We recommend that young people from families with at least 2 first-degree relatives with an aneurysm receive a preventive examination with MR angiography without contrast medium every 5–7 years from the age of 20. The prerequisite for this, however, is the clear wish of those affected for clarification.

This recommendation is based on a study by Dutch researchers from the University of Utrech *. There, in all screenings that were carried out every 5-10 years, a new aneurysm was found in 5% of the patients, even if these patients had already tested negative in earlier examinations.

Is aneurysm screening recommended if only one family member has an aneurysm?

If aneurysms do not run in families, but were diagnosed only in one first-degree family member, a screening examination for family members is not recommended. The incidence of an aneurysm in this group is not significantly higher than in the rest of the population, at least in Central Europe. The aneurysms detected are predominantly small and located in the anterior circulation, so that the risks of therapy so far exceed the benefits *.

What are the problems of screening?

The person affected must clarify in a consultation with an aneurysm expert whether a previously unknown brain aneurysm should be specifically searched for. A clear desire for clarification is an absolute prerequisite, because magnetic resonance imaging (MRI) of the head can also reveal other incidental findings. It is important to discuss beforehand possible consequences and complications of treatment, insurance aspects, the suitability for certain activities in the case of an aneurysm diagnosis or a possible detection of non-treatable findings. The mere knowledge of a diagnosis can be a considerable psychological burden for those affected, without there being any real need for medical action.


  1. Rinkel GJ. Intracranial aneurysm screening: indications and advice for practice. Lancet Neurol. 2005;4:122-128.

  2. Broderick JP, Brown RD, Sauerbeck L et al. Greater rupture risk for familial as compared to sporadic unruptured intracranial aneurysms. Stroke. 2009;40:1952-1957.

  3. Bor AS, Rinkel GJ, van Norden J, Wermer MJ. Long-term, serial screening for intracranial aneurysms in individuals with a family history of aneurysmal subarachnoid haemorrhage: a cohort study. Lancet Neurol. 2014;13:385-392.

  4. Raaymakers TW. Aneurysms in relatives of patients with subarachnoid hemorrhage: frequency and risk factors. MARS Study Group. Magnetic Resonance Angiography in Relatives of patients with Subarachnoid hemorrhage. Neurology. 1999;53:982-988.