What are the characteristic features of Marfan syndrome?

From the Guidelines

Marfan syndrome is a genetic disorder characterized by cardiovascular, skeletal, and ocular manifestations, with aortic root dilation and mitral valve prolapse being the most critical features that can lead to life-threatening aortic dissection if untreated. The condition primarily affects the cardiovascular system, skeletal system, and eyes. Cardiovascular manifestations include aortic root dilation and mitral valve prolapse, which can lead to life-threatening aortic dissection if untreated 1. Skeletal features are often the most visible signs, including:

• Tall, slender build with disproportionately long limbs (dolichostenomelia)
• Arachnodactyly (long, thin fingers)
• Pectus excavatum or carinatum (chest wall deformities)
• Scoliosis
• Joint hypermobility Ocular manifestations typically include:
• Lens dislocation (ectopia lentis)
• Severe myopia
• Increased risk of retinal detachment Other features may include spontaneous pneumothorax, dural ectasia (widening of the spinal canal), and stretch marks unrelated to weight changes. These manifestations result from mutations in the FBN1 gene, which encodes fibrillin-1, a protein essential for elastic fiber formation in connective tissue 1. The severity varies widely among affected individuals, even within families, and diagnosis typically requires meeting specific clinical criteria across multiple body systems. Management includes beta-blockers or angiotensin receptor blockers to slow aortic enlargement, regular cardiac imaging, and sometimes prophylactic aortic surgery 1.

The diagnosis of Marfan syndrome is based on the modified Ghent criteria, which incorporate genetic testing, the systemic score, ectopia lentis, and the family history 1. Patients with Marfan syndrome develop aneurysms involving the aortic root (sinuses of Valsalva) and are at risk for aortic dissection. Descending aortic and AAAs are less common. Type B aortic dissection is the initial aortic event in about 10% of patients and may also occur despite previous root replacement. Imaging surveillance of the aorta is typically performed annually, with the frequency dependent on age, aortic diameter, rate of aortic growth, and family history. Prophylactic aortic root replacement for aneurysm disease prevents type A dissection and improves survival in Marfan syndrome 1.

Aortic root dilation and type A aortic dissection are the leading causes of morbidity and mortality in Marfan syndrome. Aortic dilation involves the aortic root, but effacement of the sinotubular junction with enlargement of the proximal ascending aorta is often present. The aortic root and ascending aorta are measured by TTE and are observed annually. Nomograms accounting for age, sex, and body size (and height) assist with determining the degree to which the diameter deviates from normal in the general population 1. In patients with Marfan syndrome participating in trials of beta blockers versus angiotensin receptor blockers (ARBs), the mean growth of the aortic root was 1 mm to 1.5 mm over 3 years and 4 mm to 5 mm over 5 years. The rate of aortic dilation is faster in patients with larger aortic aneurysms. More frequent imaging is performed in patients with rapid aortic growth, in those approaching surgical thresholds, or when the diameter exceeds 4.5 cm 1.

From the Research

Characteristic Features of Marfan Syndrome

The characteristic features of Marfan syndrome include:

• Aortic root dilatation, which is the most frequent cardiovascular manifestation 2
• Aortic dissection, aortic regurgitation, and aortic rupture, which are the main causes of morbidity and mortality 2, 3
• Skeletal abnormalities, such as long limbs, arachnodactyly, and abnormal joint flexibility 4, 5
• Ocular manifestations, including dislocated lenses (ectopia lentis) and other eye problems 4, 5
• Dural sac ectasia, stretch marks, spontaneous pneumothorax, and recurrent hernia 4

Systemic Involvement

Marfan syndrome affects multiple systems of the body, including:

• Cardiovascular system: aortic root dilatation, aortic dissection, and aortic regurgitation 2, 3
• Ocular system: dislocated lenses, ectasia of the dural sac, and other eye problems 4, 5
• Skeletal system: long limbs, arachnodactyly, and abnormal joint flexibility 4, 5
• Pulmonary system: spontaneous pneumothorax 4

Diagnosis and Management

Diagnosis of Marfan syndrome is based on the Ghent II nosology, and genetic testing can help distinguish it from other heritable thoracic aortic disease syndromes 5 Management of Marfan syndrome requires medical therapy to slow the rate of growth of aneurysms and decrease the risk of dissection, as well as routine surveillance with imaging techniques to monitor aneurysm growth and determine when to perform prophylactic repair surgery 5