COL3A1 and triple-A syndrome: This study investigated the association between AAA and the thoracic aneurysm genes ACTA2, COL3A1, EFEMP2, FBN1, MYH11, MYLK, SMAD3, TGBF2, TGFBR1, TGFBR2, and MTHFR (p.Ala222Val).