A research team at UCD, lead by Dr Sean Ennis, have made a breakthrough in discovering the genetic cause of anophthalmia, a condition where babies are born without eyes.
Anophthalmia and microphthalmia are two conditions affecting the eyes where a baby may be born with no eye or only part of an eye. An article published in the December 2011 issue of Human Mutation details the discovery made by Dr Ennis and his team.
As Dr Ennis explains “with this it’s usually a double hit so you have to have the same fault coming from both parents; what that means is we look for regions of their genomes that are identically inherited from the mother and the father.” If both parents have this altered gene then each of their children have a one in four chance of being born with these eye conditions.
Several generations of a family were tested and it was found that if the child has alterations in both copies of the STRA6 gene then the eyes would not develop properly. The STRA6 gene is responsible for transporting vitamin A to the cells and if this gene is altered, not enough vitamin A can get to the foetus and ensure healthy eye development.
New technology available in the genetic field made the discovery of the disease possible using just one family. Dr Ennis explains that this is one of the first times that these new technologies in genetics have been applied to rare diseases and been successful. “It’s hard to get it across, but to be able to find the cause for a disease in just one family is kind of remarkable; we’re blown away by it ourselves, and we’ve done it.”
This new discovery means that a genetic test can now be conducted to see if couples that want to have children have this changed gene. If both parents have this altered gene then counselling can be provided to deal with the impact of carrying this gene on to future children. Dr Ennis highlights that “part of our aim with doing this … is to highlight the fact that you can now think about tackling these diseases, at least getting a handle on what is going on … people just tend to think, even scientists tend to think, that it’s just not possible to look at these things and get an answer. But it is.”
The tests are not expected to be commercialised in Ireland. According to Dr Ennis, the developed test goes back to the National Centre for Medical Genetics; “it’s government funded, so they don’t charge for the actual testing, it’s basically a service provided. I mean the university would like you to commercialise it yes, but that’s the field, you put it out in the public domain so people can use it.”