ABO and aortic aneurysm: Furthermore, it has been shown that the genetic variation of ABO is associated with atherosclerosis and biomarkers of vascular inflammation, both of which are recognised risk factors for aortic aneurysm formation and aortic dissection.1 16 17 The normal physiology of the vascular system relies on a negatively charged vascular wall, which repels the similarly negatively charged red blood cells and many negatively charged circulating proteins.