Ataxia-telangiectasia (A-T) is a complex genetic condition which from early childhood causes increasingly severe problems with movement and coordination. It weakens the immune system and greatly increases the risk of developing cancer. Although usually diagnosed in early childhood, around one person in five with A-T in the UK has a milder variant where symptoms progress more slowly and diagnosis may only be made in later life.


Medical text written January 2013 by by the A-T Society. Approved January 2013 by Dr Mohnish Suri, Consultant Clinical Geneticist and Clinical Lead of National Paediatric A-T Clinic at Nottingham University Hospitals NHS Trust, Nottingham, UK.

Although great care has been taken in the compilation and preparation of all entries to ensure accuracy, we cannot accept responsibility for any errors or omissions. Any medical information is provided is for education/information purposes and is not designed to replace medical advice by a qualified medical professional.

This entry is pending review, and certain details may no longer be up to date. Please ring our helpline or email our Rare Conditions Information Officer for more information.

What are the symptoms?

A-T usually first appears when children start sitting and standing. They are likely to have problems with balance and coordinating movements. This will increasingly affect their walking and over time cause problems controlling eye movements, slurred speech and difficulties with eating and drinking. Other involuntary movements may develop later.

Red ‘spider veins’ called telangiectasia, often develop in the white part of the eyes after a few years. While they give the condition its name, they cause few problems.

The weakened immune system can make people with A-T prone to developing chest infections. The risk of developing cancers is greatly increased, particularly leukaemia, lymphoma and breast cancer. Affected individuals are very sensitive to the effects of radiation exposure, including medical X-rays.

Although people with A-T usually live into adulthood, their life expectancy is reduced.

What are the causes?

A-T is caused by mutations in the ATM gene, which is involved in the signalling pathway used by cells to indicate that DNA is damaged and requires repair. While all cells are affected, those in the brain involved in coordinating movements and in parts of the immune system seem to be particularly vulnerable.

How is it diagnosed?

The appearance of progressive ataxia at an early age should lead to suspicion of A-T, especially if accompanied by frequent chest infections. The appearance of telangiectasia after the age of 3 or 4 years is a strong indicator as is a high level of alpha-fetoprotein in the blood. Confirmation of diagnosis is by blood testing, which is available through Professor Malcolm Taylor’s laboratory at the University of Birmingham.

How is it treated?

Treatments are to alleviate symptoms as, unfortunately, there is currently no cure for A-T. A respiratory review should be carried out every three months. Antibiotics are frequently used to treat infections and prophylactic antibiotics can be prescribed to reduce the frequency of chest infections. Immunoglobulin therapy may also be prescribed.

Problems of movement and coordination vary between patients and appropriate medications may be prescribed by a neurologist. Affected children are likely to need a wheelchair and orthotics may become necessary as the condition progresses.

Unnecessary X-rays should be avoided where possible.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
The incidence of A-T in the UK is around 3 per million, with approximately one person in 200 carrying a mutation. The mode of inheritance is autosomal recessive. In families with an affected child there is a 25 per cent chance of recurrence in further pregnancies.

Prenatal diagnosis
This is usually possible, if the specific mutations have been identified. Affected families should seek advice from a geneticist.

Is there support?

Ataxia-Telangiectasia Society (A-T Society)

Tel: 01582 760733
Email: [email protected]

The Society is a Registered Charity in England and Wales No. 1105528. It provides support to anyone affected by Ataxia-Telangiectasia (A-T), or a variant of A-T, and the people who care for them.  

Group details last updated January 2016.

Ataxia-Telangiectasia is a metabolic disease and information, support and advice is also available from Climb (see entry Inherited Metabolic diseases).

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