Marfan syndrome: An inherited disorder of connective tissue characterized by abnormalities of the eyes, skeleton, and cardiovascular system.
Myopia (nearsightedness) is the most common eye feature. Displacement of the lens from the center of the pupil occurs in over half of patients. There is an increased risk for retinal detachment, glaucoma, and early cataracts.
The skeleton shows bone overgrowth and lax joints. The arms and legs are disproportionately long, as are the fingers and toes. Due to overgrowth of the ribs, the sternum may be pushed in (pectus excavatum) or out (pectus carinatum). Scoliosis is common.
Cardiovascular manifestations include enlargement of the aorta at the level of the aortic valve, aortic aneurysm, prolapse of the mitral and tricuspid valves, and enlargement of the pulmonary artery. The major causes of morbidity (disease) and mortality (death) in the syndrome are cardiovascular.
The syndrome is inherited in an autosomal dominant manner and is caused by mutation in the FBN1 gene that encodes fibrillin 1. About three-quarters of people with the syndrome have an affected parent while a quarter have a new gene mutation. A parent with the mutation has a 50% chance of transmitting it to each child. Pregnancy can be dangerous for women with widening of the aorta.
Given good medical management, the life expectancy in Marfan syndrome now approximates that for the general population. Care may be provided by a team including a medical geneticist, ophthalmologist, orthopedist, cardiologist, and cardiothoracic surgeon. |
