What's Marfan syndrome?
Marfan syndrome is an inherited connective-tissue condition caused by changes in the FBN1 gene. It commonly affects the skeleton, the eyes, and the large blood vessel leaving the heart (the aorta).
| Also indexed as | OMIM:154700, MONDO:0007947 |
|---|---|
| Features mapped | 14 |
| Treatments mapped | 5 |
| Published sources | 14 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Arachnodactyly
Long, slender fingers (arachnodactyly) are a recognisable feature of the condition.
Aortic dissection
The most dangerous complication of Marfan syndrome is aortic dissection, a tear in the wall of the weakened, enlarged aorta. It is a surgical emergency, and preventing it is the reason the aortic root is monitored and replaced before it grows too large.
Mitral valve prolapse
Mitral valve prolapse is a heart valve that does not close smoothly, which can produce a murmur and a mid-to-late click on examination. These cardiac findings have been described in a person with Marfan syndrome.
Aortic regurgitation
As the aortic root stretches in Marfan syndrome, the aortic valve may no longer close tightly, letting blood leak backward (aortic regurgitation). Over time this extra load on the heart can contribute to heart failure.
Congestive heart failure
Severe valve leakage and aortic disease in Marfan syndrome can overwork the heart until it can no longer pump effectively, leading to heart failure. This is one of the serious cardiovascular outcomes the treatment plan aims to prevent.
Aortic root aneurysm
An aortic root aneurysm is a widening of the aorta where it leaves the heart. It is one of the cardinal features of Marfan syndrome.
Tall stature
Tall stature with a large arm span is one of the usual presenting features of Marfan syndrome.
Autosomal dominant inheritance
Marfan syndrome is inherited in an autosomal dominant pattern: a single changed copy of FBN1 can cause it, and it can be passed from an affected parent.
Myopia
Myopia, or nearsightedness, was found in a portion of the eyes studied in a group of adults with Marfan syndrome.
Ectopia lentis
Ectopia lentis means the lens inside the eye has shifted out of its normal position. It is one of the cardinal features of Marfan syndrome.
Kyphoscoliosis
Marfan syndrome often affects the spine, producing curvature such as scoliosis and a forward rounding (kyphosis). These spinal changes are part of the overgrowth of the skeleton that also produces tall stature and a long arm span.
Pectus carinatum
Pectus carinatum is a chest wall where the breastbone pushes outward. It has been described among the marfanoid features in a person with Marfan syndrome.
Scoliosis
Curvature of the spine is common and can be significant.
Joint hypermobility
Joint hypermobility means joints that move further than usual. It is one of the physical traits associated with Marfan syndrome.
How it is diagnosed
Marfan syndrome
Diagnosed using: revised Ghent criteria.
“The 2010 modified Ghent criteria are used to diagnose MFS on the basis of parameters such as cardiovascular, eye, and musculoskeletal disorders.”
Marfan syndrome
Diagnosed using: slit-lamp examination for ectopia lentis.
“The position of the lens was noted by observing the eye in different gaze directions in maximal mydriasis during slit lamp examination.”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
angiotensin receptor blockers (ARB)
Angiotensin receptor blockers such as losartan can reduce the dimensions of the aortic root in Marfan syndrome, which helps slow its widening.
Used to help with: Marfan syndrome.
“Studies have shown that losartan therapy significantly reduces the dimensions of the aortic root and sinotubular junction in children.”
beta-blockers
Beta-blockers are part of medical management in Marfan syndrome, used to reduce stress on the aorta, particularly when the heart rate is fast.
Used to help with: Marfan syndrome.
“Medical treatment consisted of betablockers, BB (for patients with tachycardia), or angiotensin II receptor blockers, ARB.”
prophylactic aortic root replacement
Prophylactic aortic root replacement is surgery performed before a dissection occurs, to prevent aortic dissection, the most dangerous complication of Marfan syndrome.
Used to help with: Marfan syndrome.
“The most dangerous manifestation of MFS is aortic dissection, which needs to be prevented by a prophylactic aortic root replacement.”
losartan
Losartan is an angiotensin receptor blocker. In a meta-analysis of seven randomized trials, it was associated with a smaller change in aortic root diameter in people with Marfan syndrome.
Used to help with: Marfan syndrome.
“In this meta-analysis including seven randomized trials, the use of losartan was associated with a significantly smaller change in aortic root diameter in patients with Marfan syndrome.”
beta-blocker or angiotensin receptor blocker therapy
For Marfan syndrome with aortic root widening, medical therapy with adequate doses of either a beta-blocker or an angiotensin receptor blocker is recommended.
Used to help with: Marfan syndrome.
“All patients with known or suspected Marfan syndrome and aortic root dilation should receive medical therapy with adequate doses of either β-blocker or angiotensin receptor blocker.”
What changes how it shows up
The diagnosis is not the whole story. The factors and open questions below are described in the research mapped here as shaping whether, or how strongly, the condition shows up, or as points the field has not yet settled. They are not, on their own, its cause or its cure.
FBN1
Marfan syndrome is an autosomal dominant condition caused by variants in the fibrillin-1 (FBN1) gene.
Described as modulating: Marfan syndrome.
“Marfan Syndrome (MFS) is an autosomal dominant condition caused by variants in the fibrillin-1 (FBN1) gene.”
How to read the evidence labels
Where this comes from
This guide is built from 14 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.