Table 2.

Diagnostic criteria for the Marfan Syndrome (Ghent Nosology).

Skeletal system	Major criteria (at least 4 of the following constitutes a major criterion)	Pectus carinatum Pectus excavatum, needing surgery Reduced upper to lower segment ratio or arm span to height ratio >1.05 Positive wrist and thumb signs Scoliosis >20° or spondylolisthesis Reduced extension of the elbows (>170°) Medial displacement of the medial malleolus causing pes planus Protrusio acetabuli of any degree, ascertained on x-ray
	Minor criteria	Pectus excavatum of moderate severity Joint hypermobility Facial appearance (dolicocephaly, malar hypoplasia, enophthalmos, retrognathia, down-slanting palpebral fissures)
		Highly arched palate with dental crowding
Ocular system	Major criteria	Ectopia lentis
	Minor criteria	Abnormally flat cornea (as measured by keratometry) Increased axial length of globe (as measured by ultrasound)
Cardiovascular system	Major criteria	Dilatation of the ascending aorta with or without aortic regurgitation and involving at least the sinuses of Valsalva Dissection of the ascending aorta
	Minor criteria	Mitral valve prolapse with or without mitral valve regurgitation Dilatation of main pulmonary artery, in the absence of valvular or peripheral pulmonary stenosis or any other obvious cause, under the age of 40 years Calcification of the mitral annulus below the age of 40 years Dilatation or dissection of the descending thoracic or abdominal aorta below the age of 50 years
Pulmonary system	Major criterion	None
	Minor criterion	Spontaneous pneumothorax Apical blebs (ascertained by chest radiography)
Skin and integument	Major criteria	Lumbosacral dural ectasia ascertained by CT or MRI
	Minor criteria	Striae atrophicae (stretch marks) not associated with marked weight change, pregnancy or repetitive stress Recurrent or incisional hernia
Family/genetic history	Major criteria	Having a parent, child, or sibling who meets the diagnostic criteria listed below independently Presence of a mutation in FBN1 known to cause the Marfan syndrome Presence of a haplotype around FBN1, inherited by descent, known to be associated with unequivocally diagnosed Marfan syndrome in the family
	Minor criteria	None
Requirement for diagnosis of Marfan syndrome	Index case	Major criteria in at least two different organ systems and involvement of a third organ system
	Family member	Presence of a major criterion in the family history and one major criterion in an organ system and involvement of a second organ system

To assess involvement of the skeletal system, at least two major criteria, or one major criterion plus two minor criteria must be present. To assess involvement of the ocular system, the major criterion or at least two minor criteria must be present. To assess involvement of the cardiovascular system, one major or minor criterion must be present. To assess involvement of the pulmonary system, one of the minor criteria must be present. To assess involvement of the skin and integument, the major criterion must be present.