Ulnar dimelia or mirror hand syndrome is a rare congenital anomaly of the upper limb characterized by absence of radius, duplication of ulna and symmetric polydactyly (seven or eight fingers and lack of thumb). Less than 100 cases have been reported in the literature till today.
Do all of the fingers function normally? Can the patient use each and every finger individually? Does the other hand have 5 digits?
Wow. I've seen sketches of what this would look like, but had never seen an actual case until now. That's amazing!