Corneal recurrent erosions dystrophy in citizens and migrants in Finland

Abstract

AbstractThe epithelial recurrent erosion dystrophy (ERED) is a rare autosomal dominant corneal disease. Recently, mutations in collagen type XVII, alpha 1 (COL17A1) gene were identified as the cause of ERED. We have identified four Finnish families and one Armenian family with recurrent erosions and a dominant inheritance pattern. Affected patients reported recurrent corneal erosions beginning at the age of 4–12 years. The frequency of erosions decreased in adult age. Corneal scarring and anterior stromal opacities with varying degree were observed. The visual acuity of some patients slowly deteriorated. Next‐generation exome sequencing was performed in seven affected individuals from the five families focusing on the large COL17A1 gene. Sequencing analysis revealed that all seven patients carried a known synonymous splice‐altering variant c.3156C>T. Furthermore, five more family members were studied with Sanger sequencing. All twelve patients carried the same c.3156C>T variant. The variant was not present in gnomAD database including of 12,562 Finns. A genealogical analysis revealed that in one Finnish family the variant originated from Sweden. The variant c.3156C>T in COL17A1 is reported previously in English, American, Thai, New Zealand, and Tasmanian families with ERED. Our finding of the same variant in yet two other populations strengthens the evidence that this variant is the most frequent cause of ERED. The c.3156C>T codon seems to be a hot spot for recurrent mutations.