What is the medical term for having extra fingers or toes?

The medical term for having extra fingers or toes is polydactyly. This condition can manifest as one or more extra digits on the hands or feet, and it can occur as an isolated condition or as part of genetic syndromes. Polydactyly is most often hereditary and can vary in complexity, ranging from a small extra nubbin to fully formed, functional digits.

Hypodactyly refers to the condition of having fewer than the normal number of fingers or toes, while syndactyly describes the situation in which two or more digits are fused together. Apert syndrome is a genetic disorder characterized by the premature fusion of skull bones, which affects the head shape and may involve syndactyly, but it is not specifically about having extra digits. Therefore, polydactyly is the accurate term for the presence of additional fingers or toes.