Treacher Collins Syndrome

Locus

Location

Gene

References

OMIM entry

TCOF1

5q32-q33.1

TCOF1

Dixon et al., 1996

154500

POLR1D 13q12.2 POLR1D Dauwerse et al., 2010 613717
POLR1C 6p21.1 POLR1C Dauwerse et al., 2010 248390

 

 

 

 

 


Treacher Collins syndrome is characterized by coloboma of the lower eyelid (the upper eyelid is involved in Goldenhar syndrome), micrognathia, microtia, hypoplasia of the zygomatic arches, macrostomia, and inferior displacement of the lateral canthi with respect to the medial canthi. The disease-causing gene, TCOF1, encodes a protein of 1,411 amino acids (TREACLE) with a structure that is shared with nucleolar trafficking proteins in other species, suggesting that TCOF1 plays a role in nucleolar-cytoplasmic transport. The detection rate for mutations in this gene in persons with the TCOF1 phenotype is approximately 60%, and in nearly all cases, the result is the introduction of a premature stop codon into the predicted protein ( Edwards et al., 1997 ).