Biallelic excision of the CTG18.1 expansion in two Fuchs endothelial corneal dystrophy-derived iPSC lines and one control (SCTCi046-A-1, SCTCi047-A-1 and SCTCi041-A-1) using an episomal vector-based CRISPR/Cas9 approach.

An expanded CTG repeat in intron 2 of the transcription factor 4 (TCF4) gene is the main cause of Fuchs endothelial corneal dystrophy (FECD), a complex corneal disease. The prevailing paradigm is that the expanded repeat exerts toxic effects, resulting in corneal endothelium degeneration. Here we explored the use of CRISPR/Cas9-mediated, non-homologous end-joining (NHEJ) for disease-modeling purposes, by performing a biallelic excision of the CTG18.1 expansion in two FECD- and one control-derived induced pluripotent stem cell lines (iPSCs). The three Δ/Δ CTG18.1 lines generated by this study provide a platform to investigate the CTG18.1 contribution to FECD pathogenesis.