Hand polydactyly Ectopic accessory finger-like appendage 2009-07-29T01:34:47Z HP:0010441 UMLS:C4023825 In contrast to forms of polydactyly where the supernumerary digit (this can either be a rudimentary or a completely 'normal' digit) is either located postaxial (on the ulnar side of the hand, next to the little finger), preaxial (on the radial side of the hand, next to the thumb) or mesoaxial (somewhere central, between thumb and little finger), a supernumerary digit may also be placed ectopically, meaning anywhere else except post-,meso- or preaxial. In the literature this is sometimes referred to as Disorganisation-like Syndrome (OMIM223200).