Diagnosis of a Chinese pedigree affected with Treacher-Collins syndrome due to a novel variant of TCOF1 gene through whole exome sequencing

Abstract

To explore the genetic etiology for a Chinese pedigree affected with Treacher-Collins syndrome (TCS) through whole exome sequencing (WES). A TCS pedigree which was diagnosed at the Women and Children's Hospital Affiliated to Qingdao University on February 5, 2020 was selected as the study subject. Following collection of clinical data, WES was carried out. Candidate variant was validated through Sanger sequencing and bioinformatic analysis. The WES results showed that the proband has harbored a heterozygous c.3337C>T variant of the TCOF1 gene, and Sanger sequencing confirmed that his mother and brother also carried the same variant. Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted as pathogenic (PVS1+PM2_Supporting+PP4). The heterozygous c.3337C>T variant of the TCOF1 gene probably underlay the pathogenesis of TCS in this pedigree.