Novel nonsense mutation in the TCOF1 gene associated with treacher collins syndrome: A case report

Treacher Collins Syndrome (TCS) is a congenital disorder characterized by craniofacial malformations. In this case, a novel likely pathogenic nonsense variant, in the <i>TCOF1</i> gene, associated with TCS, was reported. Genetic analysis was performed on an Ecuadorian participant (Subject A) and his mother (Subject B), both of whom exhibited characteristic features of TCS. Next-generation sequencing (NGS) identified a single nucleotide variant (c.4423A > T) in exon 25 of the <i>TCOF1</i> gene, resulting in a premature stop codon (p.(Lys1475Ter)) and a truncated treacle protein. The likely pathogenic variant presented in Subjects A and B could alter critical functions of the protein, contributing to the craniofacial malformations of the subjects. The variant informed in this case report contributes to the knowledge of <i>TCOF1</i> gene variants associated with TCS and highlights the importance of genomic screening for accurate diagnosis and improved clinical management in patients and families.