SNP array for Cas9 treated human zygotes

Donated 2PN human zygotes were injected with a Cas9 RNP targeting pericentromeric and mid-arm sites on chromosomes 16 and X. The purpose of this experiments was to determine if CRISPR induced genetic changes (e.g. indels or chromosomal changes) differ based on the targeted chromosome and position in the chromosome (pericentromeric vs chromosome mid-arm targets). We found whole and segmental chromosome loss in over one third of chromosomes targeted by CRISPR/Cas9.

Chromosome loss was seen after targeting different chromosomes, and different positions in the chromosome. These results highlight additional limitations of CRISPR/Cas9 genome editing, as well as potential mechanisms of origin of aneuploidies in the human embryo.