TCOF1

Treacher Collins-Franceschetti Syndrome

Clinical Characteristics
Ocular Features: 

Lid fissures often have an antimongoloid slant.  Many patients (69%) have a coloboma of the lower eyelid (in contradistinction to Goldenhar spectrum syndrome [164210] in which the lid colobomas involve the upper eyelid) with a paucity of lashes and meibomian glands medially.  Colobomas may also involve the iris, choroid and optic nerve.  Other ocular features include blepharoptosis, hypoplasia of the supraorbital ridges, absent lacrimal puncti, underdevelopment of the orbicularis oculi muscle, absence of the tarsal plate, and abnormalities of the lateral canthal tendons.  Strabismus and amblyopia have been reported in a significant number of individuals.

Systemic Features: 

A variety of defects in facial development have been reported, most involving the ears, eyelids, lower jaw, and zygomatic arch.  The characteristic facial phenotype is usually evident at birth.  One-third of patients have a cleft palate.  Microtia or even anotia may be present and a conductive hearing loss can result, especially when the ossicles are malformed or absent.  The pinnae are often malformed, appearing 'crumpled', low-set, and rotated posteriorly.  There may be ear tags and blind fistulas anywhere between the tragus and angle of the mouth.  The mandible and its rami may be hypoplastic causing severe micrognathia that can result in feeding and speaking difficulties, especially when pharyngeal hypoplasia is also present.  The zygomatic arches are often underdeveloped (or even absent) and the midface is flattened.  Arhinia and cleft palate are sometimes seen.  A low hairline may be present.  Intelligence is usually normal.

Genetics

This is an autosomal dominant syndrome secondary to mutations in the TCOF1 gene located at 5q32-q33.1.  A parental gender influence is suggested by at least one study which found an increase in the number of affected offspring from affected mothers compared with those from affected fathers.  Many cases (60%) result from new mutations but a paternal age effect has not been established.  Inter- and intrafamilial clinical variation is wide.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Auditory testing should be done early since corrective action is important in the prevention of developmental delays.  Reconstructive facial surgery can be of great benefit to both cosmesis and function.  Lid reconstruction may be required for corneal protection.

References
Article Title: 

Genotyping in 46 patients with tentative diagnosis of Treacher Collins syndrome revealed unexpected phenotypic variation

Teber OA, Gillessen-Kaesbach G, Fischer S, Bohringer S, Albrecht B, Albert A, Arslan-Kirchner M, Haan E, Hagedorn-Greiwe M, Hammans C, Henn W, Hinkel GK, Konig R, Kunstmann E, Kunze J, Neumann LM, Prott EC, Rauch A, Rott HD, Seidel H, Spranger S, Sprengel M, Zoll B, Lohmann DR, Wieczorek D. Genotyping in 46 patients with tentative diagnosis of Treacher Collins syndrome revealed unexpected phenotypic variation. Eur J Hum Genet. 2004 Nov;12(11):879-90.

PubMed ID: 
15340364
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