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