Ataxia-Telangiectasia is what is known as a genetic condition. It is inherited by a child who gets one “faulty” A-T gene from each parent. The affected child has two copies of the faulty (changed) gene. The parents have one normal gene and one faulty gene and are often called ‘carriers’. The parents do not have the condition themselves, since one normal gene is sufficient for good health. However there are implications for carriers.
It is estimated that about 1 in 200 people in the UK population are carriers of the faulty A-T gene. This is worked out from the incidence of the condition in the population. However there are variations. In particular, where there is higher rate of marriage between relatives or within a particular community, the incidence of A-T or other genetic conditions can increase.
The changes on these ‘faulty’ genes are more correctly known as ‘mutations’. No one is responsible for these mutations. Every one of us has mutations on a number of genes which could, in a double dose, lead to a genetic disorder. However, as long as the other copy we receive is normal, there is no disease.
We have made a lot of progress in A-T research in the past few years. Nevertheless, there is much more that we need to understand about how the mutation on the gene leads to the different symptoms of A-T. However a lot of research is being done to understand this and every year brings new advances in our knowledge.