Marfan syndrome: this genetic disease that can dangerously weaken the aorta

Tall stature, unusually long limbs, thin fingers, or spinal abnormalities: certain physical signs can suggest Marfan syndrome. This genetic connective tissue disorder can also affect the eyes and, most notably, the aorta, the body's main artery. Without proper monitoring, certain cardiovascular complications can become particularly serious.

Marfan syndrome is a hereditary disorder affecting connective tissue, which is present in many of the body's structures and is responsible for providing them with strength and elasticity. It is most often caused by a mutation in the FBN1 gene, which is involved in the production of fibrillin-1, a protein essential for the organization of connective tissue fibers. The disease is generally transmitted in an autosomal dominant pattern: when one parent is affected, each child has a 50% chance of inheriting the mutation. Mutations can also occur spontaneously, without any known family history.

Physical characteristics sometimes visible from childhood

Affected individuals often have a slender build, with particularly long arms, legs, and fingers. Chest deformities, scoliosis, or hypermobility of certain joints may also be observed. However, these characteristics are neither systematic nor sufficient for diagnosis. Ophthalmologically, an abnormal lens position, called ectopia lentis, is a particularly suggestive sign. Significant myopia may also be present. The diversity of manifestations explains why some people are diagnosed during childhood, while others discover their condition in adulthood.

The most feared complication involves the aorta, particularly its initial section where it exits the heart. The fragility of its wall can cause progressive dilation, called an aneurysm, which increases the risk of aortic dissection. This complication occurs when a tear develops in the inner layer of the artery wall, allowing blood to leak between its layers. It can cause sudden and extremely intense chest or back pain and constitutes a life-threatening emergency. Diagnosis of Marfan syndrome is based on clinical examination, family history, cardiac and ophthalmological evaluation, and, in some cases, genetic testing.

Cardiovascular monitoring is essential throughout life.

Management primarily aims to prevent aortic complications. Regular echocardiograms allow for measurement of the aortic diameter and monitoring of its evolution. Certain medications, including beta-blockers or angiotensin II receptor antagonists such as losartan, can be used to slow aortic dilation in some patients. When the aortic diameter reaches certain thresholds or its growth becomes a concern, preventive surgery may be recommended to replace the weakened portion before a dissection occurs.

Recommendations regarding physical activity must also be adapted. Efforts that cause very high increases in blood pressure, particularly certain intense weight training or contact sports, may be discouraged depending on the condition of the aorta. However, moderate and appropriate physical activity is generally still encouraged. Follow-up care often involves several specialists, including cardiologists, ophthalmologists, and geneticists. Thanks to regular monitoring and advances in cardiovascular surgery, the life expectancy of affected individuals has improved considerably in recent decades.

Marfan syndrome serves as a reminder that an unusual physical characteristic can sometimes reveal a genetic disorder affecting internal organs. Being tall, thin, or having long fingers obviously does not mean one has this condition. However, the combination of several suggestive signs, particularly in the presence of a family history of aortic aneurysm or dissection, warrants a specialist evaluation. Sudden and intense chest or back pain constitutes a medical emergency. The key to diagnosis is to identify any potential aortic weakness early enough to prevent complications.