Treacher Collins Syndrome Flashcards
What are some Treacher Collins Syndrome TCS Key Points?
- Treacher Collins Syndrome (TCS)
- A disorder of craniofacial development
- TCS is caused by abnormal formation of the first and second branchial arches during the 5th to 8th weeks of human fetal development, leading to profound facial dysmorphism
- Genetically and phenotypically heterogeneous
- Most cases caused by loss‐of‐function mutations in the gene TCOF1 which encodes the protein Treacle
- Other TCS cases caused by mutations to the genes POLR1D and POLR1C which encode subunits of the enzymes RNA Polymerase I and III, important in RNA synthesis
What are some signs and symptoms of Treacher Collins Syndrome (TCS)?
Signs and symptoms vary from almost unnoticeable to severe.
Most have underdeveloped facial bones, particularly the cheek bones, eye sockets and a very small jaw and chin (micrognathia).
Some people with this condition are also born with a cleft palate
In severe cases, underdevelopment of the facial bones may cause potentially life-threatening respiratory problems in the newborn.
Facial features: eyes that slant downwards, sparse eyelashes, eyelid coloboma.
Some may have eye abnormalities which may cause loss of vision
Also characterised by absent, small, or unusually formed ears. Hearing loss occurs in about half of all affected individualsWha
