Treacher Collins syndrome is characterised by a combination of the following features:
- eyes that slant down at the outer corners
- colobomas (notched lower eyelids)
- micrognathia (small lower jaw)
- cleft palate (see entry Cleft Lip and/or Palate)
- middle ear defects - the middle ear contains three small bones that transmit sound to the inner ear
- microtia (under-developed, malformed or missing ears)
- under-developed or missing cheekbones and side wall/floor of the eye socket
- small or obstructed nasal passages
- unusual hairline, with hair growing across the cheek like a sideburn.
Most children with the syndrome usually have some degree of hearing loss and those severely affected may have respiratory problems. Eye abnormalities may lead to an increased risk of eye infection and dental abnormalities may also occur. People with Treacher Collins syndrome usually have normal intelligence.