In the DiPS 1016 SevA iPSC line (called 1016 for short; C/C, major/major at rs10872142), we used CRISPR-Cas9 to knock in the minor allele (Figure 5B). Using a single-strand DNA oligonucleotide as a repair template, we obtained several heterozygous (C/A) clones (out of 140 clones screened). Heterozygous knock-in clones had decreased expression of FRK compared to wild-type clones (down 24%); when differentiated into HLCs, no difference in expression was observed (Figure 5C). CRISPRi with one of two gRNAs and the combination of the two gRNAs in HEK 293T cells (C/C, major/major at rs10872142) decreased FRK expression (Figure 5D), concordant with the data from the genome-edited iPSC clones. These findings support rs10872142-FRK as a functional SNP-gene set in iPSCs but not in HLCs.
