Marfan syndrome can be diagnosed based upon the pattern of organ involvement and knowledge of family or genetic investigations.


Systems assessed:

(1) skeletal

(2) ocular

(3) cardiovascular

(4) pulmonary

(5) skin and integument

(6) family history


Criteria for the diagnosis of the index case:

(1) involvement of 1 organ system

(2) major criteria in >= 2 different organ systems in addition to involved organ


Criteria for involvement of a system:

(1) skeletal: at least 2 of the components for the major criterion, or 1 component of the major criterion plus at least 2 of the minor criteria

(2) ocular: at least 2 of the minor criteria

(3) cardiovascular: 1 of the major or 1 of the minor

(4) pulmonary: at least 1 of the minor criteria (no major)

(5) skin and integument: the major criteria or at least one minor criterion

(6) family history: 1 of the major criteria (no minor)


Major Criteria

Minor Criteria


>= 4 of the following:

(1) pectus carinatum (ribs pushed out)

(2) pectus excavatum requiring surgery

(3) abnormal upper to lower body segment ratio or arm span to height ratio (see below)

(4) positive wrist or thumb sign

(5) scoliosis >= 20° or spondylolisthesis

(6) reduced extension of the elbows (< 170°)

(7) medial displacement of the medial malleolus causing pes planus

(8) protrusio acetabulum (any)

pectus excavatum (ribs pushed in) of moderate severity



joint hypermobility



highly arched palate with dental crowding



facial appearance (see below)


ectopia lentis

abnormally flat cornea (by keratometry)



increased axial length of the globe (by ultrasound)



hypoplastic iris or hypoplastic ciliary muscle causing a decreased miosis


dilatation of the ascending aorta with or without aortic regurgitation and involving at least the sinuses of Valsalva

mitral valve prolapse with or without mitral valve regurgitation


dissection of the ascending aorta

dilatation of the main pulmonary artery in the absence of valvular or peripheral pulmonic stenosis or any other obvious cause at age < 40 years



calcification of the mitral annulus at age < 40 years



dilatation or dissection of the descending thoracic or abdominal aorta at age < 50 years



spontaneous pneumothorax



apical blebs (may be seen on chest X-rays)


lumbosacral dural ectasia (on CT scan or MRI)

striae atrophica (stretch marks) not associated with marked weight changes, pregnancy or repetitive stress



recurrent or incisional hernias


parent, child or sib who meet the diagnostic criteria independently



presence of a mutation in FBN1 known to cause the Marfan syndrome



presence of a haplotype around the FBN1, inherited by descent, known to be associated with unequivocally diagnosed Marfan syndrome in the family



Facial features of Marfan syndrome:

(1) dolichocephaly

(2) malar hypoplasia

(3) enophthalmos

(4) retrognathia

(5) down-slanting palpebral fissures


Abnormal body ratios:

(1) reduced upper body segment to lower body segment ratio

(2) arm span to height ratio > 1.05


Hand changes (see separate section below):

(1) arachnodactyly

(2) thumb sign

(3) wrist sign

(4) joint hypermobility or hypomobility


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