Replication of SNP associations with keratoconus in a Czech cohort

INTRODUCTION Keratoconus is a relatively frequent disease leading to severe visual impairment. Existing therapies are imperfect and clinical management may benefit from improved understanding of mechanisms leading to this disease. We aim to investigate the replication of 11 single nucleotide polymorphisms (SNPs) with keratoconus. METHODS SNPs from loci previously found in association with keratoconus were genotyped in 165 keratoconus cases of Caucasian Czech origin (108 males and 57 females) and 193 population and gender-matched controls. They included rs1536482 (COL5A1), rs4839200 (KCND3), rs757219 and rs214884 (IMMP2L), rs1328083 and rs1328089 (DAOA), rs2721051 (FOXO1), rs4894535 (FNDC3B), rs4954218 (MAP3K19, RAB3GAP1), rs9938149 (ZNF469) and rs1324183 (MPDZ). A case-control association analysis was assessed using Fisher's exact tests. RESULTS The strongest association was found for rs1324183 (allelic test OR = 1.58; 95% CI, 1.10-2.24, p = 0.01). Statistically significant values were also obtained for rs2721051 (allelic test OR = 1.72; 95% CI, 1.07-2.77, p = 0.025) and rs4954218 (allelic test OR = 1.53; 95% CI, 1.01-2.34; p = 0.047) which showed an opposite effect direction compared to previously reported one. CONCLUSION Independent replication of association between two SNPs and keratoconus supports the association of these loci with the risks for the disease development, while the effect of rs4954218 warrants further investigation. Understanding the role of the genetic factors involved in keratoconus etiopathogenesis may facilitate development of novel therapies and an early detection.