Treacher Collins syndrome (also known as Franceschetti-Zwahlen-Klein syndrome or mandibulofacial dysostosis) is a rare genetic disorder characterized by craniofacial deformities. Treacher Collins syndrome is found in 1 in 10,000 births. The typical physical features include downward slanting eyes, a small lower jaw, and malformed or absent ears.
This condition is a result of a defect of the first arch during development.
It is named after Edward Treacher Collins (1862–1932), the English surgeon and ophthalmologist who described its essential traits in 1900.