The changing face of the genetics of corneal dystrophies

Modern molecular genetics has had a profound effect on our understanding of corneal dystrophies. Mutations in the BIGH3 gene are responsible for four autosomal dominant corneal dystrophies. The mutation spectrum reveals the phenotypically diverse possibilities stemming from mutations of a single gene. Dystrophies have been grouped together in a "stamp-collector" fashion. Classification has been based on clinical description of disease. With better appreciation of molecular genetics, classifications can be based on underlying genetic cause. In fact, classification schema based on the gene or molecular defect responsible for the dystrophy have been introduced. Different phenotypes are determined by different genotypes. Clinicians must become more adept at understanding the molecular genetics of corneal dystrophies as genetics is increasingly important in the long-term diagnostic and therapeutic approach to dystrophies.