Except for some particular mutations,15,16)ACTA2 alterations manifest as nonsyndromic aortic aneurysms and dissections as lesions are limited to the vascular system.17) Unlike Marfan syndrome and LDS, aortic dilatations caused by ACTA2 gene mutations tend to occur in the ascending aorta and beyond rather than in the aortic root. The gene discussed is ACTA2; the disease is aortic aneurysm.