In conclusion, the expression levels of TCF4 transcripts were altered in FECD patients—the repeat expansion caused a reduction in transcripts starting immediately downstream of CTG TNR and transcripts containing 5′ exons spliced directly to exon 4, and an increase in transcripts encoded by distal 5′ exons located hundreds of kbp downstream of the repeat. This evidence concerns the gene TCF4 and Fuchs endothelial corneal dystrophy.