Marfan syndrome is a rare disorder that causes the connective tissue in
the body to be weaker than it should be. Connective tissue is the
material which holds together many structures in the body, such as
tendons, ligaments, cartilage, blood vessels, heart valves, and more.
Because the connective tissue is weaker in Marfan patients, it affects
how the heart and blood vessels, eyes, and skeleton are formed as well as
how they work.
Marfan syndrome is thought to be an inherited disease that is caused by a
defect in a gene. Marfan syndrome can affect both men and women. Because
the gene defect can be passed down to children, Marfan patients should
talk to their doctor and a genetic counselor before having children. In
about twenty five percent of Marfan patients, neither parent had the
condition. In these patients, the condition is thought to develop because
of a mutation in the egg or the sperm
The defect in the gene that causes Marfan syndrome controls the
production of a special protein found in the connective tissue. This
protein is called fibrillin. Without enough proper fibrillin, the walls
of the major arteries are weakened. If the aorta (the main blood supplier
to the body) is affected, it gets bigger (or dilates), making it weaker.
The weakened area of the aorta can bulge outward, creating an aortic
aneurysm. Or the aorta can tear, and blood can lea through these tears
plus between the tissue of the aortic wall. This is called aortic
If the aorta is stretched and weakened, this can also affect the aortic
valve. In some patients, blood leaks backward through the valve instead
of moving in the proper one-way, forward flow. This is called
regurgitation. If too much blood flows backward, only a small amount can
travel forward to your body's organs. The heart tries to make up for this
by working harder, and with time the heart will become enlarged (dilated)
and less able to pump blood throughout the body.