Genetic Association ofTCF4Intronic Polymorphisms, CTG18.1 and rs17089887, With Fuchs' Endothelial Corneal Dystrophy in an Indian Population

PURPOSE: To assess the genetic association of transcription factor 4 (TCF4) intronic polymorphisms and CTG18.1 allele in individuals with Fuchs' endothelial corneal dystrophy (FECD) individuals from a sample Indian population. METHODS: Forty-four FECD patients and 108 unrelated age-matched controls were recruited with informed consent for this study. Three, single nucleotide polymorphisms (SNPs) spanning the third intronic region of TCF4 (rs613872, rs17089887, and rs17089925) and an unstable trinucleotide repeat CTG18.1 allele were genotyped by direct sequencing using Sanger's method. The association of polymorphisms was analyzed using χ(2) test and logistic regression. RESULTS: SNP rs17089887 (P = 0.013) and CTG18.1 (P = 2 × 10(-4)) alleles were found to be significantly associated with FECD in the sample Indian population. However, the other two SNPs, rs613872 and rs17089925, were not likewise associated. Thirty-four percent of FECD subjects and 5% of control individuals harbor more than 50 trinucleotide repeats, which was considered as the disease threshold. CONCLUSIONS: TCF4 poses a major contributor to FECD manifestation globally, with a significant association of rs17089887 and CTG18.1 allele in the Indian population.