Understanding Marfan Syndrome

A genetic disorder of the connective tissue

Marfan syndrome is a genetic condition that affects the body's connective tissue — the fibers that support and connect organs, blood vessels, bones, and muscles. It's caused by a mutation in the FBN1 gene, which provides instructions for making fibrillin-1, a protein essential to healthy connective tissue.

Because connective tissue is found throughout the body, Marfan syndrome can affect many different systems, most notably the skeletal, cardiovascular, and ocular (eye) systems, and to a lesser extent the skin, lungs, and nervous system.

Marfan syndrome is estimated to affect roughly 1 in 5,000 people worldwide, regardless of sex, race, or ethnicity.

How Marfan syndrome is diagnosed

There is no single test for Marfan syndrome. Diagnosis typically involves a physical exam, a detailed family history, an echocardiogram to check the heart and aorta, an eye exam, and often genetic testing to look for an FBN1 mutation. Doctors commonly use a set of clinical criteria (the revised Ghent nosology) that weighs findings across body systems.

Because early features can be subtle, many people aren't diagnosed until adolescence or adulthood — sometimes only after a cardiovascular event prompts further testing.

Living well with Marfan syndrome

With regular monitoring and treatment, most people with Marfan syndrome live long, active lives. Management typically includes routine echocardiograms to track aortic size, medications (such as beta-blockers or angiotensin receptor blockers) to reduce stress on the aorta, annual eye exams, and orthopedic monitoring during growth. Preventive aortic surgery may be recommended if the aorta reaches a certain size.

Most physicians also advise avoiding contact sports and intense isometric exercise (like heavy weightlifting) due to added strain on the cardiovascular system — though many aerobic activities remain safe with guidance from a cardiologist.