Allele-specific antisense oligonucleotides rescue ATAD3A disease model in zebrafish

A preprint posted to bioRxiv describes the development and preclinical evaluation of allele-specific antisense oligonucleotides (ASOs) targeting a recurrent pathogenic variant in ATAD3A, a gene encoding a mitochondrial AAA-ATPase. Pathogenic variants in ATAD3A cause a spectrum of severe multisystem disorders. The variant under study — c.1582C>T (p.Arg528Trp) — acts as a dominant negative, meaning the abnormal protein product interferes with the function of the protein produced by the normal copy of the gene.

The research team designed ASOs to selectively reduce expression of transcripts carrying the pathogenic variant while sparing the wild-type allele. Efficacy and allele-specificity were first assessed in fibroblasts derived from affected individuals, using allele-specific primers and amplicon-based next-generation sequencing. ASO candidates were then evaluated in a zebrafish model carrying the equivalent variant, where treatment was reported to rescue the associated phenotype.

The approach exploits the observation that heterozygous loss-of-function variants in ATAD3A are well tolerated, meaning selective silencing of the dominant-negative allele is a plausible therapeutic route without substantially compromising total ATAD3A function. The study is a preprint and has not yet been peer-reviewed; results in zebrafish models do not always translate to human disease contexts. The work is of interest to researchers in rare disease, RNA therapeutics, mitochondrial biology, and antisense oligonucleotide design.