It is characterized mainly by fishlike facies with receding chin, downward sloping palpebral fissures, colobomas of the eyelids, macrostomia, dysplastic ears, and other anomalies. Ear malformation are usually associated with hearing loss. Orofacial defects are symmetrical and differ from those in oculo-auriculovertebral dysplasia which generally affect one side of the body.
Mental retardation occurs in some cases.
The name Treacher Collins is sometimes erroneously hyphenated. Crumpled malformed pinnae which are usually misplaced toward the angle of the mandible, absent external auditory canals, and defective ossicles. Extra ear tags and blind fistulae may exist in the ear lobes and between the tragus and the angle of the mouth. Short and downward sloping palpebral fissures and colobomas of the lower eyelids or irides are the main ocular features. Supraorbital ridges are hypoplastic.