RT Book, Section
A1 Marsh, Karen L.
A1 Dixon, Michael J.
A2 Valle, David L.
A2 Antonarakis, Stylianos
A2 Ballabio, Andrea
A2 Beaudet, Arthur L.
A2 Mitchell, Grant A.
SR Print(0)
ID 1184076691
T1 Treacher Collins Syndrome
T2 The Online Metabolic and Molecular Bases of Inherited Disease
YR 2019
FD 2019
PB McGraw-Hill Education
PP New York, NY
SN 9780071459969
LK ommbid.mhmedical.com/content.aspx?aid=1184076691
RD 2024/04/18
AB Treacher  Collins  syndrome  (TCS)  (MIM  154500)  is  a  disorder  of  craniofacial  development  that  is  inherited  in  an  autosomal  dominant  fashion  and  occurs  with  an  incidence  of  approximately  1  in  50,000  live  births.  Forty  percent  of  patients  have  a  previous  family  history,  whereas  in  60  percent  of  patients  the  syndrome  is  thought  to  arise  as  a  result  of  a  de  novo  mutation.TCS  is  characterized  by  abnormalities  of  the  external  ears,  conductive  hearing  loss,  lateral  downward  sloping  of  the  palpebral  fissures,  cleft  palate,  and  hypoplasia  of  the  mandible  and  zygomatic  complex.  These  features  often  are  bilaterally  symmetrical  in  nature.  A  marked  variation  in  phenotype  is  observed  both  within  and  between  families.In  the  absence  of  a  candidate  gene  or  appropriate  mouse  model  for  the  disorder,  the  mutated  gene  causing  TCS  (TCOF1)  was  isolated  by  positional  cloning  strategies.  So  far,  approximately  70,  mainly  family-specific,  mutations  have  been  identified  within  the  gene,  which  maps  to  chromosome  5q32-q33.1.  The  majority  of  these  mutations  introduce  a  premature  termination  codon.Since  database  sequence  comparisons  failed  to  reveal  any  strong  homology,  little  was  known  about  the  precise  function  of  the  protein,  treacle,  encoded  by  TCOF1.  Recent  work  on  the  expression  of  treacle  suggests  that  it  is  a  member  of  a  family  of  nucleolar  phosphoproteins  and,  as  such,  may  be  involved  in  shuttling  proteins  between  the  nucleus  and  the  cytoplasm.