Mutation-Specific siRNA Knockdown of GJB2: Potential Gene Therapy for Keratitis-Ichthyosis-Deafness Syndrome

The document presents a study on the potential of mutation-specific siRNA therapy as a treatment for Keratitis-ichthyosis-deafness (KID) syndrome, which is caused by mutations in the GJB2 gene encoding connexin 26 (Cx26). The study focused on the dominant mutation D50N, found in 87% of KID patients, hypothesizing that siRNA could selectively suppress the mutant allele and potentially reverse the disease phenotype. The researchers used CRISPR/Cas9 to generate a Cx26 human keratinocyte line and developed a mutation-specific siRNA after in vitro optimization. They assessed the siRNA's specificity using HeLa cells transduced with either wild-type or mutant Cx26-GFP. The results showed an approximately 80% reduction in GJB2 mutant gene expression and a 60% decrease in mutant Cx26 protein levels, with no changes in wild-type cells. Functional recovery was evaluated in KID patient-derived keratinocytes treated with siRNA, showing significantly improved gap junction intercellular communication compared to untreated cells. These findings suggest that targeted siRNA therapy could be a feasible treatment for KID syndrome, pending effective skin delivery methods.