Linda
My husband has an aortic aneurysm at L4-5 which he never knew he had until he was x-rayed for a back problem. His measures 3.4mm. Nothing is done until it reaches 5 mm. Some people don't even know that they have one. I do not believe it is in the genes. It is often caused by weakening of the arteries(major) which could result from being overweight and smoking. You didn't mention the size of it. God bless him at age 86 - if his sons watch their lifestyle they should be in the age plus side of life also. Good luck