TCF4 and Fuchs endothelial corneal dystrophy: ASOs have recently emerged as a powerful therapeutic option for disease intervention, including those caused by trinucleotide repeat expansions.10, 39, 40, 41, 42 Here we show that a non-coding CTG trinucleotide repeat expansion in TCF4 (CTG18.1) confers greater than 76-fold risk for FECD in a large white British and Czech cohort.