However, to date, although the genotype–phenotype correlation has not been fully documented for ACTA2-related TAADs, it is suggested that the majority of aortic aneurysms or dilatation in patients with an ACTA2 mutation may result in dissections at diameters below classic surgical thresholds (aortic root diameter <50 mm) [17]. The gene discussed is ACTA2; the disease is aortic aneurysm.