Forkhead Box Protein I3 (FOXI3)

The human FOXI3 gene encodes a 420-amino acid protein.Foxi3 transcripts in the epithelium of the hair and whisker placodes and developing teeth, consistent with a functional role for the gene in the development of these organs.A 7-bp duplication within exon 1 of the Foxi3 gene that resulted in frameshift and a premature stop codon was found in hairless Chinese crested dogs and in Mexican and Peruvian hairless dogs. The phenotype of hairless dogs is classified as canine ectodermal dysplasia (CED) because these dogs have missing or abnormally shaped teeth in addition to a hair coat that is sparse or absent. CED is inherited as a monogenic autosomal semidominant trait; heterozygous dogs are hairless, and homozygous mutants die during embryogenesis.