TRPS1 is a GATA-type transcription factor expressed during tooth development.21 In humans, mutations in the TRPS1 gene cause an autosomal dominant craniofacial and skeletal dysplasia: tricho-rhino-phalangeal syndrome (TRPS).22 TRPS patients have characteristic facies, sparse hair, and skeletal abnormalities characteristic of disturbed endochondral bone formation. The gene discussed is TRPS1; the disease is skeletal dysplasia.