Polysyndactyly

**Definition:** Polysyndactyly is a form of preaxial polydactyly of fingers characterised by the presence of a thumb showing the mildest degree of duplication, being broad, bifid or with radially deviated distal phalanx. Syndactyly of various degrees of third-and-fourth fingers is occasionally present. Two forms have been characterised: unilateral and bilateral.