Treacher Collins Syndrome - Signs

Signs

The incidence of this syndrome is 1 in 50,000 live births. The presentation of symptoms in people with Treacher Collins Syndrome varies. Some individuals may be so mildly affected that they remain undiagnosed, others can have severe facial involvement and life-threatening airway compromise. Most of the features of TCS are bilateral and are already recognisable at birth. The most life threatening problem of individuals with TCS is a constricted airway, since this can give problems with breathing.

Patients are mostly characterized by the following abnormalities:

• Hypoplasia of the facial bones. Most described is an underdeveloped mandibular and zygomatic bone. This leads to a small and malformed jaw. This mandible hypoplasia can result in a malocclusion.
• Ear anomalies. The external ear anomalies consist of small, rotated or even absent ears. Also symmetric, bilateral stenosis or atresia of the external auditory canals is described. In most cases, the ossicles and the middle ear cavity were dysmorphic. Inner ear malformations are rarely described. As a result of these abnormalities a majority of the individuals with TCS are dealing with conductive hearing loss.
• Most patients experience eye problems, varying from colobomata of the lower eyelids and aplasia of lid lashes to short, downslanting palpebral fissures and missing eyelashes. Vision loss can occur and is associated with strabismus, refractive errors, and anisometropia.
• Cleft palate
• Airway problems, which are often a result of mandibular hypoplasia.

The presence of an abnormally shaped skull is not distinctive for Treacher Collins Syndrome but brachycephaly with bitemporal narrowing is sometimes observed.

Dental anomalies are seen in 60% of TCS patients. These anomalies consist in tooth agenesis (33%), enamel disformaties (20%) and malplacement of the maxillary first molars (13%). In some cases dental anomalies in combination with mandible hypoplasia result in a malocclusion, this can lead to problems with food intake and the ability to close the mouth.

Some features related to TCS are seen less frequently:

• Nasal deformity
• High-arched palate
• Coloboma of the upper lid
• Ocular hypertelorism
• Choanal atresia
• Macrostomia
• Preauricular hair displacement

Facial deformity is nowadays still associated by the general public with developmental delay, and lesser intelligence, but intelligence of patients with TCS is usually normal. The psychological and social problems associated with facial deformity may affect quality of life in a number of patients.