Polydactylism is when a person has more than five fingers or toes on each hand or foot. This extra digit can be anything from a small bump of tissue to an actual finger with a nail and bone. The extra finger or toe can grow on its own from the hand bone or off of another finger. The most common cases are those involving no bone and can be treated immediately at birth.
It is a congenital condition, which the child is born with. It could be a genetic inherited trait or the result of a variety of rare genetic disorders.
If the extra digit is only tissue, it can be tied off at birth by a doctor causing it to fall off. Depending on the placement of the extra finger or toe, and if there is bone or a joint involved, surgery can become more complicated. However, there has been great success in improving the function and mobility of the individual’s hand or foot.
Polydactyl children can have syndactylism as well, which is the fusion of fingers and/or toes.