Rare eye disorder linked to genetic mutation

A rare eye disorder that leads to colour blindness and other visual problems could be caused by a newly discovered genetic mutation, researchers believe.

Scientists at Columbia University Medical Center in the US demonstrated that mutations to the gene called ATF6 – which is a key regulator of the response designed to prevent accumulations of unfolded or mis-folded proteins in the body's cells – can lead to hereditary achromatopsia, in this case affecting the cone cells of the eye.

They used next-generation gene sequencing to analyse the skin cells from achromatopsia patients and their unaffected family members to carry out their study and found that subtle changes to ATF6 interfered with the signalling pathway that regulates the unfolded protein response.

Furthermore, they were able to conclude that the cone cells of achromatopsia are unlikely to be permanently damaged as a result of the mutation and could therefore be revived by enhancing this pathway once more.

Mutations in ATF6 have previously been linked to conditions such as diabetes and Alzheimer's disease, but this is the first time that they have been directly implicated in a human disease.

Writing in the journal Nature Genetics, the study authors said this could lead to new, targeted treatments for this eye condition.

"This finding is an example of the finest clinically based science that will ultimately allow us to overcome preventable vision loss," commented Dr George A Cioffi.

The authors added that the research demonstrated how every patient is a little different and that personalised, gene-based approaches to therapies are therefore likely to be beneficial in treating hereditary disorders.

Achromatopsia affects one in 30,000 people worldwide and targets the retina's cone cells, resulting in colour blindness, decreased vision, light sensitivity, and uncontrolled eye movement.

It typically appears in infancy and there is no effective treatment, with patients usually given dark, filtered glasses or contact lenses to reduce the symptoms.