Marfan Syndrome (MFS) is one of the most common inherited connective tissue disorders, with an incidence of 1 in 10,000-20,000 individuals. It is an autosomal dominant condition (many cases involving mutations in the fibrillin-1, or FBN1, gene) affecting both sexes equally and with a wide range of clinical severity.

Further complicating the diagnosis of MFS, each manifestation of the syndrome may have other causes. Therefore, strict criteria relying on the recognition of both the major and minor manifestations of the disease are utilized to prevent over and under diagnosis.

The major criteria, by organ system include:
1) Skeletal: (need 4)
» reduced upper:lower segment ratio
» arm span > height
» arachnodactyly with positive thumb and wrist signs
» scoliosis >20 degrees or spondylolisthesis
» pectus carinatum or pectus excavatum requiring surgery
» reduced extension of elbows
» medial displacement of medial malleolus --> pes planus
» protrusio acetabulae

2) Cardiovascular: (need one)
» dilatation of aortic root involving sinuses of Valsalva
***main cause of morbidity and mortality in these patients
» aortic dissection

3) Ocular:
» ectopia lentis (diagnosed by slit-lamp)

4) Other:
» Lumbosacral dural ectasia (diagnosed by CT or MRI)

Minor criteria, also by organ system, include:
1) Skeletal:
» moderate pectus excavatum
» joint hypermobility
» high arched palate with teeth crowding
» facial abnormalities: dolichocephaly, malar hypoplasia, enopthalmos, retrognathia, down-slanting palpebral fissures

2) Cardiovascular:
» MVP or MR
» Pulmonary artery dilatation, without stenosis, <40 y.o.
» Mitral anulus calcification <40 y.o.
» Dilatation or dissection of descending thoracic or abdominal aorta <50 y.o.

3)Ocular:
» flat cornea
» incr. acial globe length
» hypoplastic iris or ciliary muscle
» myopia
» retinal detachment

4)Other:
» Pulmonary: spontaneous pneumothorax or apical blebs
» cutaneous striae distensae
» recurrent or incisional hernias

Management of these patients requires extensive patient education, including genetics counseling. Treatment of these patients is centered around preventing aortic dissection, the main cause of mortality. Therefore daily, lifelong medical therapy with beta-blockers with the goal of maintaining the HR @ 110beats/minute after submaximal exercise should be implemented in all patients, unless contraindicated. ACE inhibitors should be added early if the patient also as valvular regurgitation, to reduce the need for valve replacement. Regular cardiovascular monitoring via physical exam and echocardiography is vital, especially for women with MFS after becoming pregnant, as there is an increased risk of dissection during this time. Patients should also restrict all strenuous activities, including but not limited to weight lifting, contact sports, and scuba diving. The data currently suggests that there should be prophylactic aortic root replacement before the diamter exceeds 5.0cm in patients with a family history of dissection, or before 5.5cm in those without a family history, or any rapid increase in size >0.5-1.0cm/yr. Once there has been an aortic repair these patients will require antibiotic prophylaxis with all future dental procedures.

With the above management, life expectancy in these patients has increased from 32 years in 1972 to 61 years in 1996, with women having a significantly longer life expectancy than men for unknown reasons.