The seven new criteria can lead to a diagnosis:In the absence of a family history of MFS:

Aortic root Z-score ≥ 2 AND ectopia lentis
Aortic root Z-score ≥ 2 AND an FBN1 mutation
Aortic root Z-score ≥ 2 AND a systemic score* > 7 points
Ectopia lentis AND an FBN1 mutation with known aortic pathologyIn the presence of a family history of MFS (as defined above):

Ectopia lentis
Systemic score* ≥ 7
Aortic root Z-score ≥ 2Points for systemic score:
Wrist AND thumb sign = 3 (wrist OR thumb sign = 1)
Pectus carinatum deformity = 2 (pectus excavatum or chest asymmetry = 1)
Hindfoot deformity = 2 (plain pes planus = 1)
Dural ectasia = 2
Protrusio acetabuli = 2
pneumothorax = 2
Reduced upper segment/lower segment ratio AND increased arm/height AND no severe scoliosis = 1
Scoliosis or thoracolumbar kyphosis = 1
Reduced elbow extension = 1
Facial features (3/5) = 1 (dolichocephaly, enophthalmos, downslanting palpebral fissures, malar hypoplasia, retrognathia)
Skin striae (stretch marks) = 1
Myopia > 3 diopters = 1
Mitral valve prolapse = 1The thumb sign (Steinbergs sign) is elicited by asking the person to flex the thumb as far as possible and then close the fingers over it. A positive thumb sign is where the entire distal phalanx is visible beyond the ulnar border of the hand, caused by a combination of hypermobility of the thumb as well as a thumb which is longer than usual.The wrist sign (Walker-Murdoch sign) is elicited by asking the person to curl the thumb and fingers of one hand around the other wrist.
At 10 to 12 weeks of pregnancy, examining a piece of placental tissue through a test called chorionic villus sampling can be performed to make a diagnosis. Another prenatal test can be performed called amniocentesis at 16 to 18 weeks of pregnancy.Marfan syndrome is expressed dominantly. This means a child with one parent a bearer of the gene has a 50% probability of getting the syndrome. In 1996, the first preimplantation genetic testing (PGT) therapy for Marfan was conducted; in essence PGT means conducting a genetic test on early-stage IVF embryo cells and discarding those embryos affected by the Marfan mutation. Prognosis
Prior to modern cardiovascular surgical techniques and medications such as losartan, and metoprolol, the prognosis of those with Marfan syndrome was not good: a range of untreatable cardiovascular issues was common. Lifespan was reduced by at least a third, and many died in their teens and twenties due to cardiovascular problems. Today, cardiovascular symptoms of Marfan syndrome are still the most significant issues in diagnosis and management of the disease, but adequate prophylactic monitoring and prophylactic therapy offers something approaching a normal lifespan, and more manifestations of the disease are being discovered as more patients live longer. Women with Marfan syndrome live longer than men. Epidemiology
Marfan syndrome affects males and females equally, and the mutation shows no ethnic or geographical bias. Estimates indicate about 1 in 5,000 to 10,000 individuals have Marfan syndrome.