Marfan syndrome is a disorder of connective tissue, the tissue that strengthens the body's structures. Disorders of connective tissue affect the skeletal system, cardiovascular system, eyes, and skin.

Marfan syndrome is caused by defects in a gene called fibrillin-1. Fibrillin-1 plays an important role as the building blocks for elastic tissue in the body. A problem with this gene results in changes in elastic tissues, particularly in the aorta, eye, and skin. The gene defect also causes overgrowth of the long bones of the body. resulting in the tall height and long arms and legs seen in persons with this syndrome. How this overgrowth happens is not well understood.

In most cases, Marfan syndrome is inherited, which means it is passed down through families. However, up to 30% of cases have no family history. Such cases are called "sporadic." In sporadic cases, the syndrome is believed to result from a spontaneous new gene defect.

Persons with Marfan syndrome are usually tall with long, thin arms and legs and spider-like fingers -- a condition called arachnodactyly. When they stretch out their arms, the lenght of their arms is significantly greater than their height.

Other symptoms include:

• Highly arched palate and crowded teeth
• Nearsightedness
• Dislocation of the lens of the eye
• Funnel chest (pectus excavatum) or pigeon breast (pectus carinatum)
• Scoliosis
• Flat feet
• Learning disability
• Thin, narrow face
• Micrognathia (small lower jaw)
• Coloboma of iris
• Hypotonia

The doctor will perform a physical exam. There may be hypermobile joints and signs of heart valve problems, aneurysms, or a collapsed lung.

An eye exam may show vision problems, defects of the lens or cornea, or retinal detachment.

The following tests may be performed:

• Echocardiogram
• Fibrillin-1 mutation testing (in some individuals)

An echocardiogram should be done every year to look at the base of the aorta.