Dorsal Dimelia: Report of Two Cases With an Emphasis On the Variation of Phenotypic Expression and a Search for Candidate Causative Genes

Abstract

Dorsal dimelia is a form of duplication along the dorsoventral axis of the developing limb. Previous authors reporting on this rare entity have stated that the essential feature of the deformity is the presence of double or circumferential nail at the tip of the finger and that the aetiology is probably related to a mutation of Engrailed-1 (En-1). In this paper we report on two cases to demonstrate that the deformity in humans may be fully or partially expressed, with or without the double nail deformity, respectively. We also reviewed reported cases in humans and experimental animals and searched our two cases for candidate causative genes within the En-1 pathway.