ARNSHL gene identification: past, present and future

Area of Science:

• Genetics
• Otolaryngology
• Molecular Biology

Background:

• Autosomal recessive non-syndromic hearing loss (ARNSHL) is the most frequent hereditary deafness, characterized by high genetic heterogeneity.
• Despite 89 identified gene loci and 76 mutations, the molecular basis of ARNSHL remains unknown in 60% of cases, with 23 loci lacking identified genes.

Purpose of the Study:

• To review and analyze strategies for identifying ARNSHL gene mutations.
• To enhance the success rate of future genetic studies for ARNSHL.

Main Methods:

• Categorization of mutation identification techniques into position-dependent and position-independent approaches.
• Review of homozygosity mapping, linkage studies (STR/SNP genotyping), Sanger sequencing, and massively parallel sequencing (MPS).
• Evaluation of position-independent methods including mouse subtractive cochlear libraries, forward genetic screening, and MPS data analysis.

Main Results:

• Position-dependent approaches involve linkage analysis and sequencing within mapped chromosomal regions.
• Position-independent approaches have successfully identified mutations in 17 out of 68 reported ARNSHL genes.
• The diversity of gene functions initially limited the candidate gene approach.

Conclusions:

• Understanding the relative success of different identification strategies is crucial for future ARNSHL research.
• Position-independent methods are vital for resolving the genetic basis of hearing loss where traditional methods fall short.
• Further research is needed to elucidate the genetic underpinnings of the remaining ARNSHL cases.