Orphanet_93338 (Polysyndactyly) or PPD4 is a form of preaxial polydactyly of fingers (see this term), a limb malformation syndrome, characterized 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. Also known as: PPD4, Preaxial polydactyly type 4.