FBN1 and Marfan syndrome: Less commonly observed in patients with SCAD are systemic inflammatory diseases in 5–12% (e.g., systemic lupus erythematosus, Crohn’s disease)1,2 and monogenic vascular connective tissue diagnoses in <5% of cases (e.g., Marfan syndrome due to FBN1 pathogenic variation or vascular Ehlers–Danlos syndrome due to COL3A1 pathogenic variation)21,22.