Table of Contents
Treacher-Collins Syndrome
a.k.a. Treacher-Collins-Franceschetti, Mandibulofacial dystosis
Main Features
Bilateral characteristic facial features: malar and mandibular hypoplasia, microstomia, coloboma of outer third of lower lid, external and middle ear anomalies
Eye Findings
- External: lateral canthus displaced downward (antimongolid slant)
- Lids: Coloboma of outer 1/3 of lower lid, lack of cilia of medial lower lid, absence of lower puncta, absence of meibomian glands
- Iris: coloboma
- Motility: Esotropia
Etiology
- Autosomal Dominant
- Mutation in the 'treacle' gene (TCOF1; 606847)
- Gene map locus 5q32-q33.1
- 35 reported mutations represent a detection rate of 60%
- Incomplete penetrance and variable expressivity
Other Findings
- Zygomatic bone may be absent
- Conductive hearing loss
- Cleft palate
- Normal intelligence
References
- Dixon, M. J. : Treacher Collins syndrome. Hum. Molec. Genet. 1996: 1391-1396, 1996
- OMIM: #154500
- Photo: American Academy of Ophthalmology