Variants in more than 10 genes/loci have been shown to be either causal or associated with the disease [7–15], among which the association between the expansion of a cytosine-thymine-guanine (CTG) trinucleotide repeat polymorphism (CTG18.1) in the intron of transcription factor 4 gene (TCF4) and FECD was replicated in many cohorts of different ethnicities [16–27]. This evidence concerns the gene TCF4 and Fuchs endothelial corneal dystrophy.