TGFBR1 and Marfan syndrome: While SCAD may occur in individuals with monogenic conditions such as Marfan Syndrome (due to FBN1 pathogenic variants), Loeys–Dietz syndrome (due to TGFBR1/2 and other transforming growth factor-β pathway gene variants), and vascular Ehlers–Danlos syndrome (due to COL3A1 variants), this is uncommon (<5%); no such molecular diagnoses have been defined for FMD.