Tooth and Nail Syndrome

**Semantic type:** Disease or Syndrome

**Definition:** A rare genetic disorder with an autosomal dominant pattern of inheritance. It is associated with mutations in the MSX-1 gene on chromosome 4 which alter ectodermal morphogenesis. Characteristic clinical signs include absent or poorly-formed dentition and brittle, spoon-shaped finger and toenails. Clinical course features an increased incidence of dental caries but is essentially benign.

**Synonyms:** - HND - Hypodontia and Nail Dysplasia - Hypodontia with Nail Dysplasia - Hypodontia-Nail Dysplasia - Witkop Syndrome