Supposing I have gentically weak vein walls, am I at higer risk of annyersms?

Yes and No. You may be at higher risk for venous aneurysms like popliteal vein aneurysms but not for arterial aneurysms. When most people think of aneurysms they think of the life threatening aneurysms that are most publicized like aortic aneurysms or aneurysms in the brain. Those aneurysms are in the arterial system and are not associated with the veins. Weak vein walls do not affect the arteries.