Finding the unknown genes behind inherited optic nerve blindness

Overview

Autosomal dominant optic atrophy is an inherited eye condition that affects the optic nerve – the specialised cable that transmits visual information from eye to brain. People with this condition start to lose vision in early childhood. It gets worse over time, usually leading to blindness by age 50.

About 6 in 10 families with autosomal dominant optic atrophy have inherited a fault in the gene OPA1. A few other families have in another gene, known as OPA3.
So there is still a significant number of people who have been diagnosed based on their clinical symptoms who don’t have a confirmed genetic diagnosis. Researchers have narrowed down the possible location of the faulty genes within the genetic code for some of these undiagnosed families, but haven’t yet identified which genes are involved.

Previous research has shown that both the OPA1 and OPA3 genes produce proteins in the battery compartments (mitochondria) inside our cells. Mitochondria generate the energy cells need to work.

In this study the team is scanning for new genetic faults that cause autosomal dominant optic atrophy in a group of unrelated patients with a strong family history of the condition but who test negative for OPA1 and OPA3. They’re also investigating whether any genes they find also affect the mitochondria.

Results from the study will mean that more people can be given a specific diagnosis and appropriate genetic counselling. They could also lead to a treatment being developed. At the moment there is no treatment at all.