TGFBR1 and Loeys-Dietz syndrome: Heterozygous mutations in the genes encoding TGF-β receptors 1 and 2 (TGFBR1 and TGFBR2, respectively) cause Loeys-Dietz syndrome, an autosomal dominant aortic aneurysm syndrome, which predisposes patients to aggressive vascular disease with widespread systemic involvement (30).