Because Ataxia-Telangiectasia is such a complex condition, it is difficult to describe A-T simply. It doesn’t help that doctors often use long and unfamiliar words to describe symptoms and effects. On this website, we aim to give as much information as we can while keeping the language as simple as possible and explaining difficult terms.
What is A-T?
Ataxia-Telangiectasia or A-T, is a rare and complex genetic disorder. It is often referred to as a ‘multi-system’ disorder because it affects a number of different systems within the body. Amongst the most significant of these are:
- Increasing difficulty in controlling and co-ordinating movements (ataxia)
- Reduced efficiency of the immune system leading to more frequent infections (immunodeficiency)
- An increased risk in developing cancers, in particular leukaemia and lymphoma
- Prominent blood vessels often in or around the eyes (telangiectasia)
- Increased sensitivity to x-rays and similar radiation
However there is great variation in how these different aspects of the disease affect different individuals. Some people may not experience all of the above symptoms, though the ataxia is almost always present to some extent.
Similarly, these problems can have knock-on effects. For example difficulty coordinating movements can make it difficult to eat and/ or swallow, which can lead to children being under-weight, or to particles of food getting into the lungs and causing problems.
What causes A-T?
A-T is caused by a defect, known as a ‘mutation’, on a particular gene, known as the ATM gene (ATM stands for ‘Ataxia-Telangiectasia Mutated’). This mutation means that the gene cannot carry out its function properly.
When this gene is not working, the body cannot properly produce a particular protein, called ATM, which should be present in every cell. ATM plays an important part in the way each cell functions and when it is absent or doesn't work as it should, this gives rise to the wide range of symptoms of A-T.
Each individual has two copies of every gene, one passed on from each parent. In order for a person to develop A-T, both copies of the gene must have a mutation. If you carry a single gene with the mutation, you will not have A-T and you will almost certainly not know you are carrying it. As many as one in 200 people may be carriers.
However, when two people carrying a single copy of the mutated gene have a child together, and both pass on the mutated gene - there is a one in four chance of this - then the child will be born with A-T.
Explaining A-T to other people
If you would like copies of a simple information leaflet for your friends and family, please contact us with a mailing address or click on the image to download the leaflet.