Marfan syndrome

Marfan syndrome, rare genetic connective tissue disorder that affects most notably the skeleton, heart, and eyes. Marfan syndrome is caused by a mutation in the FBN1 gene that alters the production of fibrillin, a protein found in connective tissue. Marfan syndrome typically is inherited as an autosomal dominant trait, meaning that a single copy of the mutated gene from one parent is sufficient to cause the condition; some cases, however, arise via spontaneous mutation.

Physical or medically relevant signs and symptoms of Marfan syndrome may be apparent at birth or emerge later in life and often vary considerably in their manifestation. Visible indications may include a tall, thin body and long fingers, legs, and arms, with an arm span nearly comparable to (in some cases greater than) height. The joints often exhibit hypermobility (flexibility beyond typical ranges), and pes planus (flat feet) is common. Other skeletal features may include scoliosis (curvature of the spine) and a breastbone that pushes outward, causing the chest to protrude, or that caves inward, giving the chest a sunken appearance. The eyes are also often affected in Marfan syndrome, owing to weakened connective fibers; the lens of the eye, for example, is commonly dislocated, and there is a high frequency of glaucoma or retinal detachment.

Less obvious symptoms arise from effects on the cardiovascular system. In particular, altered composition of heart tissues and tissues of the blood vessels can lead to serious complications. Affected individuals, for example, may develop cardiomyopathy (enlargement of the heart muscle) or arrhythmia (atypical beating of the heart), or experience damage to the tissues of the aorta, which can cause an aortic aneurysm (a bulge in the aorta wall), an aortic dissection (a tear in the inner layer of the aorta), or even an aortic rupture (a complete tear through all layers of the aorta).

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Marfan syndrome is diagnosed definitively by genetic testing, alongside consideration of various clinical criteria. Although the underlying connective tissue disease cannot be treated, the condition may be managed through routine monitoring, adjustments to lifestyle (e.g., avoiding high-exertion activities), and specialized care. Certain medications, for example, may slow damage to the cardiovascular system. Scoliosis, eye conditions, or damage to blood vessels may be addressed surgically. Depending on the degree of expression of the trait, affected individuals may die prematurely or live essentially normal lives.

Marfan syndrome is named for French physician Antoine Marfan, who first described the disorder in 1896.