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.|