IRISH sufferers of Friedreichs Ataxia and their families a re jubilant about the discovery that a rogue gene on Chromosome 9 is responsible four the disorder and there is great hope that treatment and prevention will be developed in the future. But the most immediate effect of this groundbreaking development, announced in the March 8th edition of Science, is that it will give doctors a fast and accurate way to test anyone for the gene on the basis of a single blood sample, whether or not they are known to have the disorder in their family.
"When the chromosome was initially discovered in 1988 by Dr Susan Chamberlain and her team at St Mary's Hospital, London, there was light at the end of the tunnel for us. Now we have gone through the tunnel and the possibilities of what is before us are fantastic," says Claire Creedon of Dublin, who has two children with the condition.
One in 120 Irish people carries the gene for Friedreichs Ataxia, a progressive disorder of the central nervous system which usually affects children between the ages of six and 16 years. Symptoms include a breakdown in balance and - co ordination, a slurring of speech - and, in some cases, scoliosis, diabetes and heart damage, although the intellect remains unaffected.
Scientists working in Houston and Strasbourg have discovered that these problems are caused by a lack of a hitherto unknown protein which they have named - "Frataxin". From the evidence so far, it appears that a lack of Frataxin in the spinal cord, heart and pancreas is the likely primary cause of the neuronal degeneration, cardiomyopathy and diabetes associated with the condition.
For a child to inherit the disorder, both its parents must be carriers of the defective gene. If so, the child has a one in four chance of being affected.
Dr Geoffrey Dean, medical adviser to the society, says that "the gene for Friedreichs Ataxia is held by over 30,000 people in the Republic of Ireland and this discovery will make it possible to detect those who are carriers, so that they can take the precautions which are necessary to ensure that they do not marry someone else who carries the gene. For example, if they have a brother or sister with Friedreichs Ataxia there's a highly likely chance that they are a carrier, and they can make sure that they do not have children with someone who is also a carrier."
Couples who find out after they have married that they are both carriers of the gene will be able to have amniocentesis to see if their foetus is affected. In the UK, such parents would also have the option of abortion.
The other aspect of the discovery is that "there is now great hope that in the future the disease will be preventable and treatable", says Dr Dean.
For Irish families this development is particularly poignant, since it was blood donated by (Irish families known to carry the defect which greatly contributed to the international discovery, says Ms Creedon.