The 2017 ESC guideline states that surgery is indicated in all patients with Marfan syndrome and a maximal aortic diameter ≥ 50 mm, and that in patients with additional risk factors and in patients with a TGFBR1 or TGFBR2 mutations surgery should be considered at a maximal aortic diameter ≥ 45 mm9. This evidence concerns the gene TGFBR1 and Marfan syndrome.