# Unveiling a novel GJB2 dominant K22T mutation in a Chinese family with hearing loss : A novel GJB2-dominant K22T mutation

## TL;DR

A new mutation in the GJB2 gene is found to cause hearing loss in a Chinese family, offering insights into genetic deafness.

## Contribution

The study identifies a novel GJB2 K22T mutation as a cause of hearing loss in a Chinese family.

## Key findings

- A heterozygous GJB2 K22T mutation is consistently present in affected family members.
- Structural analysis suggests the mutation disrupts Cx26 gap junction channel interactions.
- The mutation is absent in unaffected individuals, supporting its causative role in hearing loss.

## Abstract

Hearing loss constitutes one of the most prevalent conditions within the field of otolaryngology. Recent investigations have revealed that mutations in deafness-associated genes, including point mutations and variations in DNA sequences, can cause hearing impairments. With the ethology of deafness remaining unclear for a substantial portion of the affected population, further screenings for pathogenic mutations are imperative to unveil the underlying mechanisms. On this study, by using next-generation sequencing, we examine 129 commonly implicated deafness-related genes in a Chinese family with hearing loss, revealing a novel heterozygous dominant mutation in the
GJB2 gene (GJB2: c.65T>G: p. Lys22Thr). This mutation consistently occurs in affected family members but is not detected in unaffected individuals, strongly suggesting its causative role in hearing loss. Structural analysis indicates potential disruption to the Cx26 gap junction channel’s hydrogen bond and electrostatic interactions, aligning with predictions from the PolyPhen and SIFT algorithms. In conclusion, our study provides conclusive evidence that the identified heterozygous
GJB2 mutation (GJB2: c.65T>G: p. Lys22Thr), specifically the K22T alteration, is the primary determinant of the family’s deafness. This contribution enhances our understanding of the interplay between common deafness-associated genes and hearing loss, offering valuable insights for diagnostic guidance and the formulation of therapeutic strategies for this condition.