Genetic Disorders
Marfan Syndrome
마판증후군
Connective tissue disorder from FBN1 mutation (aortic aneurysm risk)
- How common
- 1 in 5,000
- Typical age
- Adolescent/young adult diagnosis
What is it?
FBN1 (15q21) mutation → defective fibrillin-1 → weak microfibrils + TGF-β overactivity → CT weakness.
Commonly affected: Cardiovascular, skeletal, ocular, lung, skin
How it develops
- FBN1 mutation (AD)Defective fibrillin-1 at 15q21
- Microfibril weaknessWeak elastic fiber scaffold
- TGF-β overactivityAortic medial degeneration
- Aneurysm + skeletal anomaliesAortic root dilation, long limbs, lens dislocation
Symptoms
- Aortic root dilation/dissectionLeading cause of death
- Lens dislocationUsually upward/temporal
- Tall, long limbsArachnodactyly (long fingers)
- Scoliosis, chest deformityPectus excavatum/carinatum
- Mitral valve prolapseMid-systolic click on auscultation
How it is examined
- Ghent criteriaAortic root + lens + family + FBN1
- Wrist/thumb signsPositive Walker-Murdoch + Steinberg
- Slit-lamp examAssess for ectopia lentis
Imaging
CXR + spine films for aortic root and scoliosis.
- Aortic dilation
- Scoliosis
Cardiac MRI/CT to measure aortic root diameter (>4 cm risk).
- Aortic root >4 cm
- Aortic dissection
Non-surgical care
- Beta-blocker (atenolol)Slows aortic dilation
- ARB (losartan)Blocks TGF-β, protects aorta
- Activity restrictionNo competitive sports or isometric exercise
- Annual echocardiogramTrack aortic root diameter
- Ophthalmology + orthoMonitor lens + scoliosis
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Aortic root ≥5.0 cm (or ≥4.5 with family hx)
Procedures that may be discussed
- Prophylactic aortic root replacement (Bentall or valve-sparing David)
- Scoliosis repair
- Lensectomy + IOL
Outlook
Untreated mean survival 32 years; with treatment + surgery, ≥70 years.