What Is Ataxia-Telangiectasia?

Ataxia-telangiectasia (A-T) is a rare genetic disorder affecting around one in 40,000 to one in 100,000 Americans. It's caused by genetic mutations that are passed down from parent to child.

A-T affects a range of body systems, including the nervous system and immune system. Personal risk factors for A-T depend on your genetics. People with A-T are also at risk for various types of cancers.

Ataxia-Telangiectasia Symptoms

Symptoms of A-T appear in infancy and very early childhood. During these developmental years, parenting adults will see signs such as abnormal head swaying and difficulties in swallowing, chewing, breathing, speaking, and walking in their child. These are symptoms of neurological damage and ataxia (loss of coordination of movement).

People with A-T have typical intelligence, but writing difficulties and slurred speech make communicating a challenge. Tics, jerky movements, and shaking make everyday activities additionally difficult.

"Telangiectasia" refers to blood vessels being dilated (widened or more open than usual). This appears as exposed tiny vessels on the surface of skin areas, especially those areas exposed to the sun. Permanent bloodshot eyes are a characteristic feature.

A-T can lead to a variety of complications. It impairs the immune system, so it increases the risk of respiratory infections. It causes a growth hormone deficiency, so growth can be impaired. Many people with A-T also show premature aging.

Causes

Ataxia-telangiectasia is caused by a genetic mutation (ATM) that is inherited, or passed down from generation to generation. Just because the genetic mutation may exist in your family gene line doesn't mean your biological children will have A-T.

Mutations need to be on both copies of each gene for the condition to develop in a child. If only one biological parent has the genetic mutation, then their child will be considered a carrier of the gene.

Parents, siblings, and children of a person with A-T (first-degree relatives) have a 50% chance of inheriting the single gene mutation and becoming an ATM gene carrier.

If two ATM carriers have a biological child, there is a 25% chance the child will have A-T. If you have concerns, consider talking to your doctor about the pros and cons of genetic testing.

Diagnosis

The process for getting a diagnosis of A-T will require a few steps. Your doctor will evaluate your medical history (patient history) and order lab tests to check your general health and rule out other neurological conditions.

Brain imaging through magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) allow specialists called neurologists to see inside your brain and examine your blood vessels for telangiectasia.

Blood tests can look for genetic characteristics of A-T, including chromosomal karyotyping (showing increased abnormalities) and testing for the ATM protein (which will be low or absent).

Since A-T is a subtype of the movement disorder known as ataxia, the differential diagnosis (a way for doctors to distinguish between two or more conditions) may consider other forms of ataxia like Friedreich's ataxia and Marie's ataxia.

Treatment

There is no specific treatment that can cure A-T. There are many treatment options when it comes to relieving certain symptoms, though. A patient with A-T may need to try different therapies and work with many types of medical and health professionals. Genetic counseling may also be considered, but it is not recommended in every case.

Treatment options include off-label prescriptions, meaning there is no approved medication for A-T treatment. Prescription medications also can be geared toward maintaining or reducing specific symptoms like tremors or targeted toward the immune system or metabolic system.

Working with a physical therapist to maintain muscle strength and working with a dietitian to learn how to consume enough calories and get all your necessary nutrients is also part of a full treatment plan.

In cases in which swallowing has become risky due to aspiration (the potential for food and drink to go into the lungs), a feeding tube known as a gastronomy tube (G-tube) may be an option. G-tubes can reduce the risk of lung damage from aspiration.

Whether it comes to treating infections that can come with having a compromised immune system or treating issues related to speech impairment, the best course of action always begins with talking to a doctor about the pros and cons.

Prognosis

The rareness of A-T makes long-term large-group studies rather difficult to achieve.

A 2006 report looked at two different studies, including:

• One was a prospective study (following people after diagnosis) done at Ataxia Telangiectasia Clinical Center at Johns Hopkins Hospital in Baltimore, which found a median survival of 25 years.
• The other was a retrospective study (looking back at cases after death has occurred) from the Ataxia Telangiectasia Children's Project, which found a median survival of 19 years.

There was, however, a wide range of results in both of these studies.

A 2011 retrospective cohort study found a 20-year survival rate of 53.4%. That study noted the prognosis for the condition had not changed since 1954. The prognosis for A-T is poor largely due to complications associated with respiratory infections and cancer.

The high likelihood of additional illness or chronic condition also complicates matters. Every patient and case is unique.

In the Johns Hopkins cohort, nine patients apparently died of complications of chemotherapy or cancer, seven of pneumonia, four had significant acute neurological deterioration associated with multiple central nervous system telangiectatic vascular abnormalities, two died from sudden unknown causes, and two died from complications of chronic lung disease.

Coping

Coping with a chronic and progressive illness is best done with a strong support network that includes both individuals you trust and medical professionals you can turn to.

While no two people or families will cope in exactly the same way, the following efforts may be helpful with progressive ataxia:

• Getting a diagnosis
• Working with sensitive health professionals
• Getting into contact with others in a similar position (for example, people of a similar age with ataxia, other parents, or local support)
• Carrying a card explaining the effects of ataxia (for instance, to explain that people are not necessarily drunk if they are unsteady on their feet and slur their words)
• Using the Internet to connect with people when mobility and speech are challenged
• Using a wheelchair for increased mobility and independence

Summary

Ataxia-telangiectasia is a rare genetic condition often diagnosed in early childhood. Its effects on the nervous system result in difficulties with coordinating movement (ataxia). Dilated blood vessels (telangiectasia) are also prominent.

A-T is caused by a gene mutation that is passed on by both biological parents. Treatment is to help prevent respiratory infections and reduce other symptoms. However, there is no cure. Many people with A-T have a shortened lifespan.

A Word From Verywell

Symptoms or a diagnosis of ataxia-telangiectasia can be scary. But you and your family are not alone in this. There is a rich and diverse team of medical professionals who want to help make living with A-T as comfortable and fulfilling as possible.