Epithelial Recurrent Erosion Dystrophy Secondary to COL17A1 c.3156C>T Mutation in a Non-white Family

To report the identification of the collagen, type XVII, alpha 1 (COL17A1) c.3156C>T mutation associated with epithelial recurrent erosion dystrophy (ERED) in a Thai family.

Slit-lamp examination was performed to determine the affected status of each member of a Thai family, with multiple members demonstrating scattered Bowman layer opacities. After genomic deoxyribonucleic acid (DNA) was isolated from saliva, polymerase chain reaction (PCR) amplification and Sanger sequencing were performed to screen COL17A1 and exons 4 and 12 of the transforming growth factor β-induced gene.

The 67-year-old proband and her 4 siblings were examined by slit-lamp biomicroscopy, which identified bilateral subepithelial opacities in the proband and in one of the 4 siblings. In both the proband and the affected sister, screening of the COL17A1 gene identified a heterozygous c.3156C>T synonymous mutation that has been previously demonstrated to introduce a cryptic splice donor site, likely leading to aberrant splicing of COL17A1. This mutation was not identified in the unaffected siblings, and no mutations were identified in exons 4 and 12 of the transforming growth factor β-induced gene in any of the screened family members.

ERED associated with a COL17A1 mutation has been previously reported in only 6 families, all white. Identification of the c.3156C>T mutation, previously identified in 5 of these 6 families, in the Thai family we report indicates conservation of the genetic basis of ERED across different races and underscores the importance of ophthalmologists around the globe being familiar with ERED, which has only recently become a recognized corneal dystrophy.