Disease Information for Treacher Collins syndrome: Definition

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  • A hereditary disorder occurring in two forms: the complete form (Franceschetti"s syndrome) is characterized by anti-mongoloid slant of the palpebral fissures, coloboma of the lower lid, micrognathia and hypoplasia of the zygomatic arches, and microtia; It is transmitted as an autosomal trait; The incomplete form (Treacher Collins syndrome) is characterized by the same anomalies in less pronounced degree; It occurs sporadically, but an autosomal dominant mode of transmission is suspected; (Dorland, 27th ed)---------------------------Treacher Collins Syndrome: AKA Franceschetti-Zwalen-Klein Syndrome; MFD1; Mandibulofacial Dysostosis; TCOF1; TCS; Treacher Collins Franceschetti Syndrome 1; discussion: Treacher Collins Syndrome is a rare inherited disorder characterized by distinctive abnormalities of the head and facial (craniofacial) area due to underdevelopment (hypoplasia) of certain portions of the skull (ie supraorbital rims and zygomatic arches); Although the symptoms and physical characteristics associated with Treacher Collins Syndrome can vary greatly in severity from patient to patient, craniofacial abnormalities tend to involve the cheekbones, jaws, mouth, ears, and/or eyes; Craniofacial malformations associated with Treacher Collins Syndrome include underdeveloped (hypoplastic) or absent cheek (malar) bones; an incompletely developed, abnormally small lower jaw (mandibular hypoplasia and micrognathia); an unusually large mouth (macrostomia); malformations of the roof of the mouth (palate); and/or dental abnormalities such as misaligned teeth (malocclusion); Affected infants may also have underdeveloped (hypoplastic) and/or malformed (dysplastic) ears (pinnae) with blind ending or absent external ear canals (microtia), resulting in hearing impairment (conductive hearing loss); In addition, infants with Treacher Collins Syndrome may exhibit abnormally downwardly slanted upper and lower eyelids (palpebral fissures), a notching (colobomas) from the outer third of the lower eyelids, and/or additional eye (ocular) abnormalities, resulting in varying degrees of visual impairment in some cases; Some individuals with the disorder have additional physical abnormalities; In approximately 40 percent of cases, Treacher Collins Syndrome is inherited as an autosomal dominant genetic trait, passed on by an affected parent; However, in about 60 percent of cases, a positive family history is not found; Such cases represent new genetic changes (mutations) that occur randomly, with no apparent cause (sporadic);

    ----------[NORD Website 2005]---------------

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