Treacher Collins syndrome, named for Edward Treacher Collins (hence, no hyphen between Treacher and Collins), is an autosomal dominant disorder that results from embryologic abnormalities that affect the second and third brachial arches. The condition has variable penetrance and phenotypic expression. The majority of cases (60%) are sporadic, with 40% presenting with a family history of disease.
Also known as mandibulofacial dysostosis, Treacher Collins syndrome is characterized by anomalous (often bilateral and symmetric) development of multiple structures arising from the second and third brachial arches. These problems can be surgically corrected.
- Eyelids: Antimongoloid slanting of the eyes (outer canthus is lower than the inner canthus), shortened palpebral fissures, lower lid colobomas, absent eyelashes. Colobomas are usually corrected during the 1st year of life.
- Zygomatic bones: Small or absent zygomatic arches. Usually corrected between 4–10 years of age.
- Maxilla: Narrow or overprojected maxilla, elevated or narrow palate.
- Mandible: Hypoplasia, dental malocclusion, retruded chin. Usually corrected between 4–10 years of age.
- Nose: Broad or protruded.
- External ear: External auditory canal anomalies (stenotic or atretic in >80% of patients), pinna deformity. Can result in conductive hearing loss. Pinna repair is usually after the age of 6 (requires adequate costal cartilage development).
- Middle ear: Middle ear malformations. Can result in conductive hearing loss.
- Mouth: Microstomia.
References
- Katorza E, Nahama-Allouche C, Castaigne V, Gonzales M, Galliani E, Marlin S, Jouannic JM, Rosenblatt J, le Pointe HD, Garel C. Prenatal evaluation of the middle ear and diagnosis of middle ear hypoplasia using MRI. Pediatr Radiol. 2011 May;41(5):652-7.
- Lowe LH, Booth TN, Joglar JM, Rollins NK. Midface anomalies in children. Radiographics. 2000 Jul-Aug;20(4):907-22.
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