CTG18.1 trinucleotide repeat expansion in Polish patients with Fuchs endothelial corneal dystrophy

Abstract

PurposeTo genotype the CTG18.1 repeat expansion in TCF4 gene and determine an association between genetic variant and Fuchs endothelial corneal dystrophy (FECD) development in Polish patients.To analyze possible reationship between the different CTG18.1 genotypes and clinical picture of the patients.MethodsClinical evaluation was based on slit‐lamp examination, in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS‐OCT). Genomic DNA was isolated from peripheral blood samples of unrelated FECD patients (n = 236) and control subjects (n = 58). We genotype the CTG18.1 repeat expansion to determine an association between the genetic variant and FECD development and to analyse possible relationships between the different CTG18.1 genotypes and clinical picture of the patients. For this purpose a combination of methods, i.e. analysis of short tandem repeats (STR), triplet repeat primed PCR (TP‐PCR) and statistical analysis were performed.ResultsThe results showed that the repeat expansion CTG18.1 is currently the strongest predisposing factor for the development of FECD in a group of Polish patients (OR=43,72; CI:13,20‐144,83; χ2 = 80,77; p < 0,0001). There were no significant associations between the CTG18.1 genotype and the best corrected visual acuity (BCVA), central corneal thickness (CCT) or the density of the corneal endothelium.ConclusionsOur study confirms association of CTG18.1 repeat expansion with FECD by testing a novel previously not analysed population. This genetic determinant has an important predictive value and may be beneficial in clinical practice.