Your doctor will ask about any family history of Marfan's syndrome, as well as about any family members who are unusually tall and thin, whether or not they have vision problems. Your doctor also may ask about any family history of sudden death resulting from aortic dissection or rupture.
Your doctor may suspect Marfan's syndrome based on this family history and your physical appearance. The diagnosis can be confirmed if you have a history of ectopia lentis and also have a dilated aortic root (the first part of the aorta as it exits the heart) visible on echocardiography. Echocardiography is a painless test that uses sound waves to outline the structure of the heart and its major vessels. The diagnosis will be even more certain if you have other skeletal abnormalities (chest wall deformities or scoliosis), or heart murmurs due to aortic or mitral valve abnormalities. Genetic testing can check for specific chromosomal abnormalities related to abnormal fibrillin production.