PT  - JOURNAL ARTICLE
AU  - Isabel Weisheit
AU  - Joseph Kroeger
AU  - Rainer Malik
AU  - Julien Klimmt
AU  - Dennis Crusius
AU  - Angelika Dannert
AU  - Martin Dichgans
AU  - Dominik Paquet
TI  - Detection of deleterious on-target effects after HDR-mediated CRISPR editing
AID  - 10.1101/2020.03.27.012104
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.03.27.012104
4099  - http://biorxiv.org/content/early/2020/03/29/2020.03.27.012104.short
4100  - http://biorxiv.org/content/early/2020/03/29/2020.03.27.012104.full
AB  - CRISPR genome editing is a promising tool for translational research but can cause undesired editing outcomes, both on-target at the edited locus and off-target at other genomic loci. We investigated the occurrence of deleterious on-target effects in human stem cells after insertion of disease-related mutations by homology-directed repair (HDR). We identified large, mono-allelic genomic deletions and loss-of-heterozygosity that escaped standard quality controls in up to 40% of edited clones. To reliably detect such events, we developed simple, low-cost and universally applicable quantitative genotyping PCR (qgPCR) as well as sequencing-based tools and suggest their usage as additional quality controls after editing. This will help to ensure the integrity of edited loci and increase the reliability of CRISPR editing.