Sheikhzadeh et al developed a simple score for evaluating a patient for Marfan syndrome. This can help to identify a patient who may benefit from a more extensive evaluation. The authors are from University Hospital Eppendorf and Charite Universitatsmedizin in Germany.
Parameters:
(1) family history of Marfan syndrome
(2) history of thoracic aortic surgery
(3) wrist and thumb signs (The thumb sign is when the entire nail of the thumb is visible when a hand is clamped around the ipsilateral thumb. The wrist sign is that the nails of the first and fifth fingers overlap when one hand is wrapped around the opposite wrist).
(4) pectus excavatum
(5) history of pneumothorax
(6) striae
(7) ectopia lentis
|
Parameter |
Finding |
Points |
|
ectopia lentis |
absent |
0 |
|
|
present |
4 |
|
family history of Marfan’s syndrome |
absent |
0 |
|
|
present |
2 |
|
history of thoracic aortic surgery |
absent |
0 |
|
|
present |
1 |
|
wrist and thumb sign |
absent |
0 |
|
|
present |
1 |
|
pectus excavatum |
absent |
0 |
|
|
present |
1 |
|
history of pneumothorax |
absent |
0 |
|
|
present |
1 |
|
striae |
absent |
0 |
|
|
present |
1 |
where:
• The point assignment was based on rounding the multivariate regression coefficients to the nearest integer.
• An alternative method is to divide the coefficients by the minimum one (in this case 0.79) then round to the nearest integer.
• The wrist and thumb sign is presumed to be the Walker Murdoch sign (the entire distal phalanx of the thumb overlaps the entire distal phalanx of the fifth finger when they are placed to encircle the opposite wrist).
• Striae are considered significant if (1) they cannot be explained by weight change or pregnancy and (2) in uncommon sites such as upper arm, axilla, thigh or lumbar area.
score =
= SUM(points for all 7 parameters)
Interpretation:
• minimum score: 0
• maximum score: 11
• The higher the score the more likely that the patient may have Marfan syndrome.
• Additional testing will be required to make a final diagnosis.
• An alternative strategy is to say that Marfan syndrome should be suspected if the patient has ectopia lentis, a family history plus 2 other findings, or 4 or more other findings.
|
Score |
Probability of Marfan Syndrome |
|
0 or 1 |
low (12%) |
|
2 or 3 |
intermediate (40-60%) |
|
>= 4 |
high (91%) |
where:
• The breakpoint for intermediate group was > 1 and <= 3.5. Since the score can only be an integer the above values are used instead.
Performance:
• The score was tested in a high prevalence population. Performance may be lower if the test is used in the general public.
Specialty: Genetics
