SLC26A4 C.317C > A Variant: Functional Analysis and Patient-Derived Induced Pluripotent Stem Line Development

Area of Science:

• Genetics
• Molecular Biology
• Otolaryngology

Background:

• The SLC26A4 gene is a major genetic cause of hereditary hearing loss globally.
• Missense variants in SLC26A4 are frequent, but their functional consequences are often unknown.
• There is a critical need for in vitro models to study SLC26A4 variant effects on protein function.

Purpose of the Study:

• To establish an in vitro system for evaluating the functional impact of SLC26A4 variants.
• To investigate the specific effects of identified SLC26A4 variants on protein expression and localization.

Main Methods:

• Genetic testing to identify SLC26A4 variants in patients.
• Plasmid transfection to assess protein expression and subcellular localization.
• Generation of induced pluripotent stem cells (iPSCs) from patient peripheral blood mononuclear cells (PBMCs).

Main Results:

• Identified compound heterozygous variants (c.919-2A>G and c.317C>A) in the SLC26A4 gene.
• The c.317C>A variant significantly reduced SLC26A4 mRNA and protein expression.
• This variant caused SLC26A4 protein aggregation in the cytoplasm.
• Successfully generated and validated patient-derived iPSCs with retained pluripotency and genetic integrity.

Conclusions:

• The study elucidates the molecular mechanisms underlying SLC26A4-associated hearing loss.
• The findings highlight the detrimental effects of the c.317C>A variant on SLC26A4 protein function.
• The developed in vitro system and iPSCs provide a valuable platform for future research into hereditary hearing loss.