Are aneurysm's hereditary?

Not Mendelian: Not hereditary in the mendelian sense. Some families have higher incidence of aneurysms. Cofactors such as hypertension, diet and smoking habits may play a role in this. Connective tissue disorders are hereditary and some of these are associated with aneurysms but this is an indirect effect. I do not routinely screen family members but a negative mra can be reassuring.

Sometimes: Aneurysms can have many causes. Some of them are hereditary. Many are not. For some cases, like Marfan disease, we even know the gene.

Sometimes: About 1/4 to 1/3 of abdominal aortic aneurysm (AAA) are found in "family clusters," meaning one or more additional members of immediate family have AAA. Its higher if index case is female. So, when AAA is found, the parents, siblings and children of the person with the aneurysm are recommended to have an ultrasound (at least when they reach 60 y.o.) to check for AAA. Hope this helps.