Macklin, B. L. | Search bioRxiv

bioRxiv2026

EXCAVATE-HT: A Bioinformatic Pipeline to Identify Targetable Genomic Variants for Allele-Specific Editing

Allele-specific CRISPR/Cas editing is a powerful tool with great potential for treating genetic diseases and for uncovering the effects of allelic diversity. By targeting commonly inherited single nucleotide polymorphisms (SNPs), a small number of gRNAs can treat many more individuals than targeting rare disease mutations. However, current tools for identifying common targetable variants and generating CRISPR guide RNAs (gRNA) have fundamental conceptual and technical limitations. Here, we introduce EXCAVATE-HT (EXtracting Common Allelic VAriants for Targeted Editing in High-Throughput) a bioinformatic tool that mines population variant data to generate CRISPR libraries targeting genomic loci for allele-specific editing. Users define their loci of interest, Cas species, and SNP frequency, then EXCAVATE-HT outputs an annotated list of allele-specific gRNAs. EXCAVATE-HT can also generate libraries of gRNA pairs to enable excision. We illustrate the use of EXCAVATE-HT to design and characterize multiple gRNA libraries for allele-specific targeting of the disease gene, Cone-Rod Homeobox (CRX). EXCAVATE-HT revealed multiple excisions that could treat >30-fold more patients than targeting a single CRX disease mutation.

bioinformatics↗

bioRxiv2024

Neuronal DNA repair reveals strategies to influence CRISPR editing outcomes

Genome editing is poised to revolutionize treatment of genetic diseases, but poor understanding and control of DNA repair outcomes hinders its therapeutic potential. DNA repair is especially understudied in nondividing cells like neurons, which must withstand decades of DNA damage without replicating. This lack of knowledge limits the efficiency and precision of genome editing in clinically relevant cells. To address this, we used induced pluripotent stem cells (iPSCs) and iPSC-derived neurons to examine how postmitotic human neurons repair Cas9-induced DNA damage. We discovered that neurons can take weeks to fully resolve this damage, compared to just days in isogenic iPSCs. Furthermore, Cas9-treated neurons upregulated unexpected DNA repair genes, including factors canonically associated with replication. Manipulating this response with chemical or genetic perturbations allowed us to direct neuronal repair toward desired editing outcomes. By studying DNA repair in postmitotic human cells, we uncovered unforeseen challenges and opportunities for precise therapeutic editing.

molecular biology↗