Treacher Collins syndrome
Treacher Collins syndrome (also known as Franceschetti-Zwahlen-Klein syndrome or mandibulofacial dysostosis) is a rare genetic disorder characterized by craniofacial deformities. It is also known as Treacher Collins-Franceschetti syndrome and mandibulofacial dysostosis. Treacher Collins syndrome is found in 1 in every 50,000 births. The typical physical features include downward slanting eyes, a small lower jaw, and malformed or absent ears. more...
Its most common name is after Dr Edward Treacher Collins (1862-1932), English surgeon and ophthalmologist, who described the essential traits of the syndrome in 1900.
The disease is caused by mutations in the TCOF1 gene (chromosome 5q32-q33.1). The protein coded by this gene is called treacle and has been hypothesised to assist in protein sorting during particular stages in embryonic development, particularly that of the structures of the head and face. The disorder is inherited in an autosomal dominant pattern.
The signs and symptoms of this disorder vary greatly, ranging from almost unnoticeable to severe. Most affected individuals have underdeveloped facial bones, which result in a sunken appearance in the middle of the face, a prominent nose, and a very small jaw and chin (micrognathia). Some people with this condition are also born with an opening in the roof of the mouth called a cleft palate. In severe cases, underdevelopment of the facial bones may restrict an affected infant's airway, causing potentially life-threatening respiratory problems.
People with Treacher Collins syndrome often have eyes that slant downward, sparse eyelashes, and a notch in the lower eyelids called a coloboma. This condition is also characterized by absent, small, or unusually formed ears (pinnae), called microtia. Defects in the middle ear (which contains three small bones that transmit sound) cause hearing loss in about half of cases. People with Treacher Collins syndrome usually have normal intelligence.
Read more at Wikipedia.org