One-Size-Fits-Many: Antisense oligonucleotides for rescuing splicing mutations in hotspot exons.

Area of Science:

• Genetics
• Molecular Biology
• Bioinformatics

Background:

• Splicing mutations are a significant cause of genetic diseases.
• The precise impact of exonic variants on splicing remains incompletely understood.
• Understanding these variants is crucial for genetic diagnostics and therapeutics.

Purpose of the Study:

• To characterize the splicing impact of exonic variants in 71 clinically-actionable genes.
• To identify hotspots of splicing susceptibility within exons.
• To explore therapeutic strategies for splicing-related genetic disorders.

Main Methods:

• Analysis of 32,112 exonic mutations from ClinVar and Geisinger MyCode databases.
• Utilized a minigene reporter assay to assess splicing disruption.
• Investigated the efficacy of antisense oligonucleotides (ASOs) in correcting splicing defects.

Main Results:

• Identified 1,733 splice-disrupting mutations, with the most severe 1-2% deemed likely deleterious.
• Discovered that splice-disrupting variants are concentrated in approximately 8% of exons (hotspot exons).
• Demonstrated that splicing defects in hotspot exons can be reverted using ASOs targeting flanking splice sites.

Conclusions:

• Exonic variants impacting splicing are not randomly distributed but cluster in specific hotspot exons.
• Therapeutic ASOs targeting splice sites offer a feasible strategy to correct splicing defects caused by variants in these hotspot exons.
• This approach holds promise for developing single ASO therapies effective against multiple splice-altering variants within a particular exon.