Mutation in exon 13 of the TCOF1 gene in patient with Treacher Collins syndrome

Abstract

Treacher Collins Syndrome (TCS) is associated with an abnormal differentiation of the first and the second pharyngeal arch during fetal development. This causes mostly craniofacial deformities, which require numerous corrective surgeries. TCS is an autosomal dominant disorder and it occurs in general population with the frequency of in 1 in 50,000 live births. TCS is caused by mutations in the TCOF1 gene. This gene encodes the serine/alanine-rich protein named Treacle. TCS can also be caused by mutations in the POLR1C and POLR1D genes.

About 70% of recognized mutations of the TCOF1 gene are deletions, which lead to a frame shift,  formation of termination codon and shortening of the protein product of the gene. A heterozygous insertion c.2013_2014insG was described in one patient with TCS. The insertion causes premature termination of translation at 680aa.