Among them, 51 patients had genetically confirmed HTAD (Marfan syndrome (FBN1), Loeys-Dietz syndrome (TGFBR1, TGFBR2, SMAD3, TGFB2), vascular Ehlers-Danlos syndrome (COLSA1), and non-syndromic HTAD (ACTA2, MYH11, MYLK)). This evidence concerns the gene ACTA2 and Loeys-Dietz syndrome.