COL17A1 and corneal dystrophy: Given that COL17A1 protein is a component of hemidesmosomes that are responsible for anchoring corneal epithelial cells to the epithelial basement membrane, Sullivan and colleagues identified COL17A1 as a positional and functional candidate gene for the cause of chromosome 10q23-q24 linked corneal dystrophy.[12] While screening of the 56 exons and exon/intron junctions of COL17A1 did not identify any presumed pathogenic mutations, one novel coding region variant was identified in the affected individual and absent in the unaffected individual that was screened.