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

Abstract

Treacher Collins Syndrome (TCS) is a congenital disorder characterized by craniofacial malformations. In this case, a novel likely pathogenic nonsense variant, in the TCOF1 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 TCOF1 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 TCOF1 gene variants associated with TCS and highlights the importance of genomic screening for accurate diagnosis and improved clinical management in patients and families.

Keywords: Case report; TCOF1; genetics; genomics; treacher collins syndrome.

Figure 1.

A: Maxillofacial malformations of subject A at birth. A downward slant of the palpebral fissures, ptosis of the upper eyelids, retrognathia, lower eyelid pseudocolobomas, low-set ears, and hypoplastic cheekbones can be observed; B: Craniofacial dysmorphism of subject A at 15 days old; C: Phenotypic comparison between subject A and TCS composite photo. Areas in red and yellow indicate regions with high similarity. Image was generated using the software Face2Gene.

Figure 2.

Family pedigree of subjects A and B.

Figure 3.

Timeline displaying the relevant clinical events for both subjects.