Prophylactic surgical repair of the aorta to prevent subsequent dissection or rupture is indicated for individuals with familial TAAD and/or a confirmed mutation in MYH11 or ACTA2, when the diameter of the ascending aorta is between 4.5 and 5.0 cm, and for individuals with familial TAAD when other relatives have experienced aortic dissection with documented minimal enlargement of the aortic diameter [14]. The gene discussed is ACTA2; the disease is Aortic dissection.