What are the other Names for this Condition? (Also known as/Synonyms)

• A-T (Ataxia-Telangiectasia)
• Cerebello-Oculocutaneous Telangiectasia
• Louis-Bar Syndrome

What is Ataxia Telangiectasia? (Definition/Background Information)

• Ataxia Telangiectasia (A-T) is an uncommon, inherited disorder affecting the brain, spinal cord, and immune system
• The term ‘ataxia’ refers to problems with body balance and co-ordination, due to loss of control of movement. ‘Telangiectasia’ refers to tiny blood vessels that have become enormous. These two key features compose the general significance or meaning of what this condition is
• Children with Ataxia-Telangiectasia have poor coordination of movements, problems in maintaining posture, speech difficulties, and spider-like veins on the skin and eyes
• Currently, there is no definitive treatment and prevention of Ataxia Telangiectasia
• The prognosis of A-T is also poor despite management measures such as symptomatic treatment and medical support

Who gets Ataxia Telangiectasia? (Age and Sex Distribution)

• Ataxia Telangiectasia is a rare congenital disorder that presents during the early stages of life; the symptoms become apparent by the age of 5 years
• A-T affects both male and female genders equally
• Presently, there are no studies to indicate that the disorder is more prevalent among a particular race or ethnic group

What are the Risk Factors for Ataxia Telangiectasia? (Predisposing Factors)

• The main risk factors associated with Ataxia Telangiectasia is a positive family history of the disorder
• Individuals, who have close (blood-related) members with the disorder, are very likely to inherit the condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Ataxia Telangiectasia? (Etiology)

• Ataxia-Telangiectasia is an autosomal recessive immunodeficiency disorder that is caused by mutation of the ATM gene
• This means that both parents must provide a defective gene for  the child to be affected by this disorder
• Mutation of this gene leads to destruction of cells in different areas of the body including the brain

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children, born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Ataxia Telangiectasia?

Signs and symptoms present with Ataxia Telangiectasia include:

• Poor coordination of movements resulting in ataxic gait, jerky gait, and unsteadiness
• Lack of ability to balance and maintain posture
• Defects in speech
• Spider-like veins visible along the skin and eyes
• Recurrent lung, sinus, and ear infection
• Slow physical and sexual maturation

How is Ataxia Telangiectasia Diagnosed?

The diagnosis of Ataxia-Telangiectasia may include:

A complete evaluation of medical history along with a thorough physical exam

• The patient’s medical history will be taken with focus on the family history
• During physical examination, a complete neurological examination will be performed to assess balance, coordination, and other neurological functions
• Skin and eyes shall be examined for the presence of telangiectasia

Some of the diagnostic tests may include:

• Alpha-fetoprotein test: Elevated levels in blood may be observed, after the child is over 2 years
• Low levels of B and T lymphocytes and also immunoglobulins IgE and Ig A. Immunoglobulins are proteins produced by B and T cells to fight against infections
• X-ray to study the neck and determine the size of the thymus gland; however, x-rays may not be a suitable imaging tool for A-T affected individuals
• MRI scan to check for any brain damage
• Genetic tests to check for mutation in the ATM  gene

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Ataxia Telangiectasia?

The possible complications that may develop due to Ataxia Telangiectasia include:

• Diabetes
• Cancer such as leukemia or lymphoma: A-T affected individuals have an extremely high risk of cancer than the general population
• Deformity in the curvature of the spine
• Impaired movements
• Recurrent lung infections
• Regardless of the above complications, the affected individuals will generally remain to have normal intelligence.

How is Ataxia Telangiectasia Treated?

There is currently no treatment available for Ataxia Telangiectasia.

• The treatment is directed at symptom management to ease the patients
• Injections may be given to help enhance the immune system
• The patients will be closely followed and observed
• Physical and speech therapy can be beneficial
• Use of assistive devices such as wheelchairs
• Gene therapy can be provided, but the outcome is not very  good

How can Ataxia Telangiectasia be Prevented?

• Currently, there are no specific methods or guidelines to prevent Ataxia Telangiectasia, since it is a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

What is the Prognosis of Ataxia Telangiectasia? (Outcomes/Resolutions)

• The prognosis for Ataxia Telangiectasia is very poor.
• Most of the affected individuals may not survive beyond the early stages of life; nevertheless, the life span does differ on a case-to-case basis
• According to the US National Cancer Institute (NCI), most patients do not survive beyond their twenties
• A-T affected individuals typically remain frail and vulnerable. In case of any complication, such as cancer, radiation therapy (or cancer therapy) cannot be conducted, as it creates severe irritation and stress on them
• In many cases, these affected individuals are wheelchair bound as early as during their teens

Additional and Relevant Useful Information for Ataxia Telangiectasia:

Ataxia telangiectasia is a rare condition; the incidence of A-T may range from 1 in 40,000 to 1 in 100,000 (per NCI).