Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder characterized by manifestations in the cardiovascular, skeletal, ocular, and other organ systems. MFS type1 (MFS1) is caused by mutations in the gene encoding fibrillin (FBN1). Recently, the transforming growth factor-β receptor-2 gene,TGFBR2, has been shown to be associated with a second type of this disorder with typically mild or absent ocular involvement (MFS type 2; MFS2). Several point mutations were found in the highly conserved serine/threonine kinase domain ofTGFBR2. Mutations in bothTGFBR1andTGFBR2are associated with Loeys-Dietz aortic aneurysm syndrome (LDS). We searched forTGFBR1andTGFBR2mutations in 41 unrelated patients fulfilling the diagnostic criteria of Ghent nosology or with the tentative diagnosis of Marfan syndrome, in whom mutations in theFBN1coding region were not identified. InTGFBR1, two mutations and two polymorphisms were detected. InTGFBR2, five mutations and six polymorphisms were identified. Reexamination of patients with aTGFBR1orTGFBR2mutation revealed extensive clinical overlap between patients with MFS1, MFS2, and LDS. Hum Mutat 27(8), 770–777, 2006. © 2006 Wiley-Liss, Inc.