Thursday, July 4, 2013

Symbrachydactyly of the Foot

Symbrachydactyly, or short webbed fingers, is a birth difference which almost always affects one arm.  I have blogged about this anomaly several times- this is a link to all relevant posts.  http://congenitalhand.wustl.edu/search/label/Symbrachydactyly

One of the ways we differentiate symbrachydactyly from other anomalies is that it is almost always affects only one arm.  When more than one arm is affected or if the feet are also affected, other diagnoses such as amniotic constriction band must be considered.  Very rarely, the foot can be affected with symbrachydactyly (again, typically only one foot with a normal other foot and normal hands).

There are only a few reports of foot involvement in symbrachydactyly.  The most comprehensive is by Uchida in 1995 on 17 patients  http://www.ncbi.nlm.nih.gov/pubmed/7705729.  2 did have hand involvement also and 1 had a Polands syndrome (the most common association with symbrachydactyly of the upper extremity).  Polands syndrome is a lack of normal development of the chest muscles.

The reason to make this diagnosis is twofold.  First, to use the diagnosis to rule out other associated conditions.  What I mean is that if we diagnose symbrachydactyly, we do not expect serious internal organ issues such as problems with the heart, lungs, etc.  And second, symbrachydactyly is almost always a random, sporadic issue so that there is no predictable genetic transmission.  So if the parents have other children or if/ when the affected child has children, we should not expect others to be affected.



Symbrachydactyly of the foot.  Note the short 3rd and 4th toes.  No other extremities or digits were involved.

Despite the "normal" appearance of the great toe, second toe and 5th toe, the x-rays show that all toes are short in this child with symbrachydactyly of the foot.

8 comments:

  1. Great blog Dr Goldfarb, very useful information for people affected by symbrachydactyly. It's the first time I come across a picture of a foot affected by symbrachydactlyly in a similar way to my daughter's. The only difference is that she has all three middle digits affected. I was told at the hospital in London where we were seen that it was most likely due to an amniotic band in early pregnancy. Her twin sister was unaffected.

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    1. Mimi,

      Thank you for your comment on the usefulness of the blog- great to hear! So many of the kids that we see have a diagnosis of amniotic band and often, I believe symbrachydactyly (whether of the hands or the feet) is the correct diagnosis. The two other key facts are that this is the only extremity affected- I think (amniotic constriction band is most often more than one extremity) and the fact that her twin was unaffected.

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  2. Thank you for sharing, it is so difficult to find information on this!
    I am also a mother of twins (MoDi, meaning they shared a placenta and blood supply & are genetically identical).
    One of my girls has a central transverse symbrachydactyly. Her 1st & 5th toes are hypoplastic and have only one phalanx, the middle three toes have no bone. The other twin is not affected.

    Do you believe this may be more common amongst twins (mine are MoDi so shared a placenta)?

    I asked Professor Tonkin, who I am lucky enough to work with (I am a hand therapist), who does not know of any link between twins and congenital anomalies, however I would be interested in your opinion on this.

    Thank you!

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    1. Justine. Thank you for the comments on your twins. You are fortunate indeed to work with Dr Tonkin who is a friend and a great resource for all of us who care for kids with birth differences of the upper extremity. I was fortunate to spend time with him years ago. I have not seen specific prevalence evidence that this is more common amongst twins but it does make some sense to me. There is evidence that symbrachydactyly is caused by a decreased blood supply which affects the growing limb- twin births may affect blood supply.

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  3. Hi, my son has just been diagnosed with symbrachydactyly. His left arm stops at the elbow joint. I have been searching for information on this condition and everything I've found implies that the hand and fingers are affected. Could we have had a wrong diagnosis and should we seek a 2nd opinion? My son is 6 months old. Many thanks

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    1. Hello,
      Symbrachydactyly is a broad term. Initially, there were 4 types of hand/ wirst involvement and then 3 additional types were added to include deficiencies at the wrist and forearm level. The difference between a proximal symbrachydactyly, like your son might have, and a congenital amputation is not always clear. If there are nubbins, many surgeons would consider it symbrachydactyly. One question is how did this happen. Neither symbrachydactyly nor congenital amputation or genetic- rather we believe the symbrachydactyly arm simply never formed correctly because of a low blood flow issue early in pregnancy whereas the congenital amputation implies a loss of the fully formed arm. I hope that is helpful.

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  4. Dr. Goldfarb, this is a great page. Thank you for taking the time to devote your energy just to lower extremity symbrachydactyly. There is such an affinity for hand and finger research with this condition and it means a lot you're willing to write just about feet and toes. Why do so many researchers limit the definition for symbrachydactyly to just hands and fingers, if feet and toes can be involved, too?

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    1. Thank you. There is certainly a need to learn more!

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