physical anomaly resulting in supernumerary fingers and/or toes
Left hand with sixth finger

Polydactyly is a birth defect which may affects the hands, feet, or both. It causes one or more extra fingers or toes. It can affect people, and other mammals such as dogs, and cats.[1]


  1. Kaneshiro N. 2009. Polydactyly. http://www.umm.edu/ency/article/003176.htm