Poster abstracts
Poster number 61 submitted by Victoria Rose
Systematic CLN3 Batten disease mutation characterization for splice-switching oligonucleotide design
Victoria Rose (Cellular and Molecular Biology, University of Michigan Medical School), Kyra Auchampach (Department of Pharmacology, University of Michigan Medical School), Darren Christie (Department of Pharmacology, University of Michigan Medical School), Jessica L. Centa (School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science), Michelle Hastings (Department of Pharmacology, University of Michigan Medical School)
Abstract:
CLN3 Batten Disease is a fatal pediatric neurodegenerative lysosomal storage disorder caused by heterogenous autosomal recessive mutations in the CLN3 gene encoding the CLN3 protein. The most common disease-causing variant is a ~1kb deletion of exon 7 and 8 (CLN3∆ex7/8) which causes a frameshift and introduces a premature termination codon (PTC) in exon 9. However, more than 130 ultra-rare pathogenic mutations spanning all 15 coding exons and many intronic regions have been identified, including insertions, deletions, substitutions, and duplications. The rarity and heterogeneity of CLN3 Batten Disease makes development of conventional therapies difficult. Splice-switching oligonucleotides (SSO) offer a promising alternative, with demonstrated clinical success in treating individuals carrying unique pathogenic variants (n-of-1). SSOs are short sequences of modified nucleic acids that can be designed to selectively base-pair to an RNA target and modulate pre-mRNA splicing. Successful SSO design, however, requires a thorough understanding of how the mutation alters pre-mRNA splicing. For example, a missense mutation at a conserved splice site could induce, among other things, exon skipping or intron retention, highlighting how even a single nucleotide change can have profound and sometimes unpredictable effects on RNA processing. To facilitate SSO development, we used a panel of patient-derived CLN3 fibroblasts and the published literature to systematically characterize the effects of known pathogenic mutations on RNA processing. We then grouped these mutations by their effect and proposed SSO-based strategies to restore either full length (FL) CLN3 or the correct reading frame.
Keywords: Splice Switching Antisense Oligonucleotides, CLN3 Batten Disease