The objective of this study is to determine whether a simple blood test can be a useful clinical tool for monitoring aortic disease in Marfan syndrome and Marfan-related disorders.

The primary objective of this study is to determine whether increased quantitites of circulating microfibril fragments, measured with a simple blood test, are associated with aortic root size and increased growth of the aortic root in Marfan syndrome and related disorders. The secondary objectives of this study are to: (1) Determine a Marfan "signature" profile of circulating microfibril fragments. (2) Determine if high concentrations of fibrillin-1 fragments are associated with large aortic root diameters. (3) Determine which fibrillin-1 fragments are good biomarkers for aortic root growth and size in Marfan syndrome. (4) Determine the relation between fibrillin-1, aortic root diameter, and medical and lifestyle factors reported on questionnaires.

Inclusion Criteria:

• Age 4-26 years of age for all participants
• Diagnosis of Marfan syndrome, Loeys-Dietz syndrome, vascular Ehlers-Danlos syndrome, or Familial Thoracic Aortic Aneurysm and Dissection for inclusion in Marfan and Marfan-related disorders groups
• Diagnosis of unaffected by Marfan syndrome and Marfan-related disorders for inclusion in control group
• Able and willing to sign informed consent/assent
• Signed HIPPA compliant research authorization

Exclusion Criteria:

• Other known cardiovascular disorder for unaffected controls

The study population includes 3 groups: (1) individuals with Marfan syndrome; (2) individuals with Marfan-related disorders; (3) unaffected controls. Both genders, ages 4 to 26, will be included. Geographic locations will include the Pacific Northwest, Texas, and the Salt Lake City/Denver areas.