Researchers have discovered that people who carry a mutated form of the transcription factor 4 gene (TCF4) have as much as a 30-fold increased risk of developing Fuchs's corneal dystrophy (FCD), compared with people who do not carry the mutation, leading experts to believe a genetic test for FCD may be a future possibility.
FCD, which is exacerbated by cataract and laser eye surgery and is a leading cause of corneal transplants, affects as many as five per cent of the adult population in countries such as the United States, and there is currently no cure. Dr Albert Edwards, from the Institute for Molecular Biology at the University of Oregon, US, and his team carried out a genome-wide association study of 130 people with FCD and 260 age- and sex-matched controls, to see whether there were any common genetic patterns among the FCD patients.
The strongest association was noted for TCF4, encoding a member of the E-protein family (E2-2), which increased the risk for FCD by 5.5 times if the participant had one copy of the mutated form of the gene, and by 30.0 times if they had two copies.
'Although rare genetic variation that contributes to both early-onset and typical late-onset forms of FCD has been identified, to our knowledge, no common variants have been reported', explained Dr Edwards and his team in the New England Journal of Medicine.
The researchers also tested the discriminative ability of TCF4 to distinguish between cases of FCD and controls among the original cohort, and confirmed their findings in an independent set of 300 FCD patients and matched controls. They found it to be 76 per cent accurate.
In an accompanying editorial, Alan Wright and Baljean Dhillon from the University of Edinburgh, Scotland, explain that FCD is a degenerative disease leading to a progressive loss of endothelial cells, corneal clouding, and eventually loss of sight. They write: 'New surgical techniques offer hope in FCD but are technically highly demanding - like putting a ship in a bottle. However, prevention is better than a cure, and a simple genetic test might highlight patients who are at risk of complications after either cataract of refractive surgery.'