Comprehensive Analysis and Genetic Insights Into GJB2 c.35delG Mutation-Associated Non-Syndromic Hearing Loss in...

Area of Science:

• Genetics
• Audiology
• Molecular Biology

Background:

• Nonsyndromic sensorineural hearing loss (NSHL) is a common genetic disorder.
• The GJB2 gene is frequently implicated in hearing loss, with the c.35delG mutation being a prevalent cause in various populations.
• Understanding the prevalence of specific mutations in diverse ethnic groups is crucial for genetic diagnostics and counseling.

Purpose of the Study:

• To determine the frequency of the GJB2 c.35delG mutation in Moroccan patients with prelingual bilateral NSHL.
• To compare the mutation's prevalence with that observed in other North African populations.
• To investigate the genotype-phenotype correlation of the c.35delG mutation in the studied cohort.

Main Methods:

• A retrospective cohort study involving 304 unrelated Moroccan patients with NSHL.
• Genomic DNA extraction from blood samples.
• Detection of the GJB2 c.35delG mutation using PCR amplification and Sanger sequencing.

Main Results:

• The GJB2 c.35delG mutation was identified in 18% of the Moroccan NSHL cohort, with homozygosity being the most common genotype.
• A higher prevalence of the mutation was observed in patients from consanguineous families.
• Early-onset, bilateral, and profound hearing loss showed a strong correlation with the c.35delG mutation, consistent with regional North African data.

Conclusions:

• The GJB2 c.35delG mutation is a major contributor to NSHL in Morocco, with a prevalence aligning with other North African populations.
• The findings underscore the importance of integrating GJB2 genetic screening into diagnostic and preventive strategies for hearing loss, especially in populations with high consanguinity.
• Early genetic screening can facilitate timely diagnosis, genetic counseling, and targeted interventions for hearing loss.