Case report of Treacher–Collins syndrome with a review of its pathogenesis

Treacher–Collins syndrome (TCS) is a rare autosomal-dominant orofacial anomaly which is also known as Franceschetti–Zwahlen–Klein syndrome and mandibulofacial dysostosis. Edward Treacher Collins, a renowned British ophthalmologist, first illustrated this orofacial anomaly in 1900. This craniofacial dysmorphogenic disorder shows features such as hypoplasia of the malar bone and mandible, downward slanting of the lower palpebral fissure, external ear malformation, coloboma of the eyelids, dental abnormalities like malocclusion, and open bite. Pathogenesis of TCS is due to a mutation of the TCOF1 gene. As a result of the mutation of the TCOF1 gene, there is a defect in the formation of the phosphoprotein treacle. This phosphoprotein is very much related to the proliferation and survival of cephalic neural crest cells. As there is a defect in treacle, there is an altered function of neural crest cells which ultimately leads to the manifestation of TCS. Here, we report a case of TCS in a 21-year-old female patient.