CRISPR-Cas9-Mediated Correction of <i>TSC2</i> Pathogenic Variants in iPSCs from Patients with Tuberous Sclerosis Complex Type 2

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by mutations in either the <i>TSC1</i> or <i>TSC2</i> genes. Though TSC causes the formation of nonmalignant tumors throughout multiple organs, the most frequent causes of mortality and morbidity are due to neurological complications. In two-thirds of cases, TSC occurs sporadically and <i>TSC2</i> pathogenic variants are approximately three times more prevalent than <i>TSC1</i> pathogenic variants. Here, we utilized CRISPR-Cas9-mediated homology directed repair in patient induced pluripotent stem cells (iPSCs) to correct two types of <i>TSC2</i> pathogenic variants generating two isogenic lines. In one line, we corrected a splice acceptor variant (c.2743-1G>A), which causes the skipping of coding exon 23 and subsequent frameshift and introduction of a stop codon in coding exon 25. In the second line, we corrected a missense variant in coding exon 40 within the GTPase-activating protein domain (c.5228G>A, p.R1743Q). The generation of TSC2 patient iPSCs in parallel with their corresponding CRISPR-corrected isogenic lines will be an important tool for disease modeling applications and for developing therapeutics.