In caucasians, it is unusual and may be associated with a syndrome, such as Ellis Van Creveld, among others. http://omim.org/entry/225500?search=postaxial%20polydactyly&highlight=postaxial%20polydactyly
We can help rule out an associated syndrome.
|Small extra digit, a postaxial polydactyly.|
|Another view of the extra digit prior to surgical excision|
|Small "wart" after "tie off" procedure for ulnar polydactyly|
|Another example of skin lesion after a "tie off" procedure for ulnar polydactyly|
For that reason, when I am able to see patients with postaxial polydactyly in the office, I offer two treatment options: the office based "tie- off" procedure and a formal surgery. The surgery is quite small and offers an appearance benefit. It is a very different surgery than reconstruction of other extra digits, such as radial polydactyly. http://congenitalhand.wustl.edu/2012/05/difficult-extra-thumbs.html
Either way, most patients with this anomaly do wonderfully.