FBN1 and Marfan syndrome: Historically, the understanding of heritable TAAD was anchored in syndromic disorders such as Marfan syndrome (caused by pathogenic FBN1 variants) and LDS (linked to TGFBR1, TGFBR2, SMAD3, SMAD2, TGFB2, and TGFB3), conditions defined by clear Mendelian inheritance patterns and systemic features [2].