Another odontoblasts-related phenotype was found in association with a 4-bp deletion mutation in the Distal-Less Homeobox 3 (Dlx3) gene, which is etiologic for most cases of Tricho-dento-osseous syndrome; a disorder characterized by abnormalities in the thickness and density of bones and teeth. Here, DLX3 is linked to tricho-dento-osseous syndrome.