FBN1 and Marfan syndrome: As causative genes of syndromic aortic aneurysms and dissections in our cases, mutations of the FBN1 gene responsible for Marfan syndrome, the transforming growth factor (TGF)-β-related genes responsible for Loeys–Dietz syndrome (LDS), and the COL3A1 gene responsible for vascular Ehlers–Danlos syndrome (EDS) account for approximately 70%, 20%, and 10%, respectively.