The official diagnostic criteria for Marfan syndrome (officially known as the Ghent Nosology) have been changed yet again, but this system seems to be a bit streamlined from the previous versions.
Now, if there are any physicians reading this: DIAGNOSTIC CRITERIA ARE NOT THE SAME AS “SYMPTOMS”!!!
One of the perpetual problems is doctors looking at the *diagnostic criteria*, and then looking at some particular problem and saying, “Marfan doesn’t cause that.” Well, the point of the diagnostic criteria are the things that are more likely to occur in Marfan. The old Ghent Nosology was based upon a “Major” and “minor” criteria.
What they used to call “minor criteria” are not called “Systematic Features”. Some of the old ones have been eliminated.
The new Systematic Features:
1. Wrist AND thumb sign. These are poplularly misinterpreted. Officially, the “thumb sign” is that, with the hand in a fist, the person’s thumb can stick out past the palm of the hand. The “Wrist Sign” is that, with the fingers wrapped around the arm bones of the wrist (not the joint), the thumb can cover the fingernail of the fifth finger. (3 points)
2. Wrist OR thumb sign (1 point)
3. Pectus Carinatum (2)
4. Pectus excavatum or chest asymmetry (1)
5. Hindfoot Deformity (2)
6. Plain Flat Foot (2)
7. Pneumothorax (2)
8. Dural Ectasia (2)
9. Protrusio Acetubulae. Hip ball is too far into the socket. (2)
10. Increased armspan and leg length and decreased torso–in other words, what Marfan originally described (1)
11. thoracolumbar kyphosis or scoliosis (1)
12. Reduced elbow extension (1)
13. 3 of 5 facial features (1)
15. Skin Striae-stretch marks not caused by the usual reasons (1)
16. Myopia (1)
17. Mitral valve prolapse (1)
According to the new criteria, you need a “systematic score” of at least 7.
For conditions I’m diagnosed with according to the descriptions they give, I’ve got an 8. Jury’s still out on dural ectasia, or whether I”ve ever actually had a pneumothorax, so those would bring it up to 12.
The other thing that matters is the “Z-Score” on the aorta. For children, it should be a Z-Score of >= 3, or for adults, >=2.
The criteria are now based upon how to distinguish Marfan from related disorders. The new system puts the weight of diagnosis on the aorta and ectopia lentis, with or without family history or positive FBN1 gene test.
Now, the key diagnostic criteria are basically:
Aortic root dilation (with the above Z-Scores) OR dissection
Ectopia Lentis (dislocation of subluxation of the lens)
A positive FBN1 test
A “Systematic Score” (above) of 7 or higher.
A “Systematic Score” of 7 or higher indicates a connective tissue disorder in general, and requires a differential diagnostic to rule out Sprintzen Goldberg, vascular Ehlers-Danlos or Loeys-Dietz.
A family history of Marfan (MFS) and EITHER Ectopia Lentis OR aortic root dilation is sufficient for diagnosis.
A family history of MFS and a System Score of 7–with the above disorders ruled out–is sufficient for diagnosis.
Without Family History:
Aortic Root AND Ectopia Lentis — Definitely Marfan
Aortic Root AND any FBN1 mutation — Definitely Marfan
Ectopia Lentis AND an FBN1 mutation that is known to cause aortic dilation — Definitely Marfan
Aortic Root, with a System Score of 7 and related disorders ruled out