|
|
|
« Back
Clearing Up Confusion About Diagnosing Marfan Syndrome -- Or Adding More?
|
Posted on: 09/15/2010
|
If you've ever seen a photograph of Abraham Lincoln you know he had a long, thin face. He was thin and tall, and he had long arms and long fingers. There has been some thought that he might have had a genetic disorder of the connective tissue called Marfan syndrome. All of these physical features are typical with Marfan syndrome. Newer evidence suggests he had a different (but very similar) disorder. But the association of Abraham Lincoln's name with Marfan Syndrome has forever put this condition on the map.
New information and improved diagnostic testing has spurred the authors of this article to write about improving the recognition of Marfan Syndrome. It is a genetically inherited condition, so genetic testing is one way to prove someone has Marfan syndrome. But genetic testing is expensive and doctors have to identify who might have this disorder before sending anyone and everyone to the genetics expert.
The most serious complications are the defects of the heart valves and aorta. It can also affect the lungs, eyes, the dural sac surrounding the spinal cord, the skeleton, and the hard palate. A family history is helpful but sometimes it doesn't come until a family member dies of heart complications from Marfan syndrome. Early diagnosis and treatment can prevent such a serious outcome.
Physicians from The Johns Hopkins University (Orthopedic and Pediatric departments) studied two groups of people (those with known Marfan syndrome and those without) to see if they could identify any features that would tell them for sure who had Marfan syndrome. Since Marfan syndrome is fairly uncommon, there were only 183 patients in the Marfan group. Over 1200 people were in the nonMarfan (comparison) group.
Since the skeletal features are the most obvious, they started with those first. These include the long, thin face, a deformity called craniofacial dolichocephaly. Scoliosis (curvature of the spine), a high-arched palate (roof of the mouth), and chest deformities (caved in or protruding out) are other physical signs of Marfan syndrome. Severe flat feet called hindfoot valgus is another common feature of Marfan syndrome.
There are a couple of physical tests that can be helpful in identifying Marfan syndrome. One is the positive thumb or Steinberg sign. The other is the positive wrist or Walker-Murdoch sign. If the patient puts the thumb across the palm and closes the fingers and the thumb pokes out the other (little finger) side, there's a positive thumb sign. If the patient can circle the forearm with the thumb and little finger of the other hand and cover the entire nail of the little finger with the thumb, there is a positive wrist sign.
X-rays are an easy and fairly inexpensive way to look for evidence of Marfan syndrome. Besides the skeletal features already mentioned, the presence of acetabular protrusio is diagnostic. Aceatbular protrusio means the acetabulum or hip socket is too deep and may protrude into the pelvis. But again, not every child needs hip X-rays. So how does the pediatrician know who might have Marfan syndrome in need of diagnostic test to confirm the suspicion?
Well, that's the dilemma these authors faced because on the one hand, many children (people) have one or even more of the telltale characteristics of Marfan syndrome -- but they don't actually have this connective tissue disorder. And just as many folks who actually have the syndrome have invisible signs (like heart problems) that could lead to their premature death.
After analyzing all the data, looking at which tests were specific and sensitive enough to be counted on, the authors offered pediatricians the following steps to take:
First, ask about a family history of Marfan syndrome, especially any family members who may have died because of the heart complications.
Next, conduct a physical exam. Look the child (patient) over from head to toe with enough clothes off to be able to see any deformities present.
Third, look at the fingers. If they are long and slender, then conduct the thumb and wrist tests as described.
If there is any suspicion of Marfan syndrome from these first three steps, then look for other characteristic features of this disorder. Order pelvic X-rays and/or an echocardiogram (for the heart) if needed.
When making the decision whether to refer for a genetic evaluation, the primary care physician will weigh all the evidence and talk with the family. It can be a challenge to decide if the genetic referral is warranted, given how long genetic testing takes and how much it costs. If the test turns out to be "negative", then everyone breathes a sigh of relief. That's better than missing the diagnosis because of a lack of testing. Hopefully, this new algorithm (model for decision-making) will help improve the accuracy of referral and diagnosis.
|
References:
Paul D. Sponseller, MD, et al. Improving Clinical Recognition of Marfan Syndrome. In The Journal of Bone & Joint Surgery. August 2010. Vol. 92-A. No. 9. Pp. 1868-1875.
|
|
|
« Back
|
|
|
|
*Disclaimer:*The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic. |
 | All content provided by eORTHOPOD® is a registered trademark of Mosaic Medical Group, L.L.C.. Content is the sole property of Mosaic Medical Group, LLC and used herein by permission. |
|
