Treacher Collins syndrome - development

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What is Treacher Collins syndrome
disorder of craniofacial development
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what is TCS 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
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what are most cases caused by (loss of function mutation in what gene)
loss‐of‐function mutations in the gene TCOF1 which encodes the protein Treacle
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What are other TCS cases caused by ..what other mutations to what genes
mutations to the genes POLR1D and POLR1C which encode subunits of the enzymes RNA Polymerase I and III, important in RNA synthesis
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what are the features of this syndrome
underdeveloped facial bones, particularly the cheek bones, eye sockets and a very small jaw and chin (micrognathia), some are born with cleft palates
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what are the facial features in this syndrome
eyes that slant downwards, sparse eyelashes, eyelid coloboma. Some may have eye abnormalities which may cause loss of vision. characterised by absent, small, or unusually formed ears. Hearing loss occurs in about half of all affected individuals
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what is the main concern in newborns with TCS
Respiratory failure , due to airway narrowing from craniofacial malformation
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what is used to improve hearing in these patients
Bone conduction hearing aids or middle ear surgery are usually used to improve hearing in these patients
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what are TCOF1 mutation inherited via
via an autosomal dominant pattern,
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what are POLR1D, POLR1C mutations inherited by
autosomal dominant (POLR1D) and autosomal recessive (POLR1C) patterns.
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what kind of mutations are associated with this syndrome
deletions, which range in size from one to 40 nucleotides , splicing mutations, insertions and non-sense mutations
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what are the result of these mutations
ntroduce a premature termination codon for translation, resulting in a truncated Treacle protein which is small and non-functional
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what role does the protein TREACLE play
role in pre‐ribosomal processing and making of the ribosome
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Card 2

Front

what is TCS caused by

Back

abnormal formation of the first and second branchial arches during the 5th to 8th weeks of human fetal development, leading to profound facial dysmorphism

Card 3

Front

what are most cases caused by (loss of function mutation in what gene)

Back

Preview of the front of card 3

Card 4

Front

What are other TCS cases caused by ..what other mutations to what genes

Back

Preview of the front of card 4

Card 5

Front

what are the features of this syndrome

Back

Preview of the front of card 5
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