Treacher-Collins syndrome or mandibular facial dysostosis is a rare genetic disorder associated with craniofacial malformations such as missing cheekbones. Common physical characteristics include downward-looking eyes, microgantia (small mandible), hearing loss, immature zygoma (cheekbones), sagging of the lateral part of the lower eyelids and deformed ears, or no ear.
Treacher-Collins Syndrome; Mandibular Facial Dysostosis; Genetic Disorder; Tcof1 Gene