HOXD13-Associated Limb Abnormalities

HOXD13-associated limb abnormalities are malformations affecting the hands and feet that occur during neonatal development. Diagnostic features include abnormalities of the hand and foot including synpolydactyly and brachydactyly. Synpolydactyly involves the fusion of the third and fourth fingers of the hand and the fourth and fifth toes in the foot along with a possible inclusion of a supernumerary digit within the syndactylous web. Brachydactyly type D and E involve the shortening of the distal phalanx of the thumb and shortening of the metacarpals, respectively. Other less common phenotypic presentations include syndactyly type V, syndactyly of metacarpals and metatarsals, and a brachydactyly-syndactyly syndrome (Zhao et al., 2007). The clinical presentation of HOXD13-associated limb abnormalities can be present in isolation or as part of various syndromes. Additionally, mutations in the HOXD13 have been reported with synpolydactyly and hypospadias in males (Tuzel et al., 2007).