TGFBR1 and Marfan syndrome: Mutations underlying classic Marfan syndrome involve the FBN1 gene, whereas mutations in TGFBR1 and 2, SMAD2 and 3, and TGFB2 and 3 can be detected in Loeys-Dietz syndrome types 1 to 6, and a Col3A1 gene mutation has been described for the vascular type of EDS2,3.