A p.C343S missense mutation in PJVK causes progressive hearing loss

Area of Science:

• Genetics
• Otolaryngology
• Molecular Biology

Background:

• Nonsyndromic hearing loss (NSHL) is a common genetic disorder.
• Mutations in the PJVK gene are known to cause autosomal recessive NSHL at the DFNB59 locus.
• Pejvakin (PJVK) plays a crucial role in auditory and neural signaling within the inner ear.

Purpose of the Study:

• To investigate the genetic cause of sensorineural progressive hearing loss in a consanguineous Pakistani family.
• To identify mutations in the PJVK gene associated with hearing loss in this family.
• To determine the frequency of PJVK mutations in Pakistani families with moderate to severe hearing loss.

Main Methods:

• Genetic linkage analysis to the DFNB59 locus.
• Sequencing of the PJVK gene.
• Segregation analysis of identified mutations within the family.
• Phylogenetic analysis of the affected residue.

Main Results:

• A novel missense mutation, c.1028G>C (p.C343S), was identified in exon 7 of the PJVK gene.
• This mutation co-segregated with the progressive hearing loss phenotype in the Pakistani family.
• The affected residue (p.C343) is evolutionarily conserved across vertebrate species.
• PJVK mutations were found to be uncommon in Pakistani families with moderate to severe hearing loss.

Conclusions:

• This study reports the first PJVK mutation in a Pakistani family, confirming its role in DFNB59-related hearing loss.
• The identified mutation pinpoints a critical residue (p.C343) essential for PJVK protein function.
• Mutations in PJVK are not a frequent cause of moderate to severe hearing loss in the Pakistani population.