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WHAT IS A-T?
A Multi-system
Disease...
Ataxia-telangiectasia, or "A-T," is a progressive,
degenerative disease that affects a startling variety of body
systems. Children with A-T appear normal at birth, and the
first signs of the disease usually appear during the second
year of life. These first signs are usually a "wobbly" lack of
balance and slurred speech caused by "ataxia," which means a
lack of muscle control.
Ataxia...
The onset of this ataxia marks the beginning of progressive
degeneration of a part of the brain, known as the cerebellum,
that gradually leads to a general lack of muscle control, and
eventually confines the patient to a wheelchair. Because of
the worsening ataxia, children with A-T lose their ability to
write, and speech also becomes slowed and slurred. Even
reading eventually becomes impossible as eye movements become
difficult to control.
Telangiectasia...
Soon after the onset of the ataxia, the A-T patient usually
shows another clinical hallmark of A-T: "telangiectasia," or
tiny red "spider" veins which appear in the corners of the
eyes or on the surface of the ears and cheeks exposed to
sunlight. Although these telangiectasia are seemingly
harmless, their unique appearance together with ataxia is what
led to naming this disease "ataxia-telangiectasia."
Immune System
Problems...
For most (about 70 percent) of children with A-T there is
another clinical hallmark: immunodeficiency that usually
brings recurrent respiratory infections. In many patients,
these infections can become life threatening. Because of
deficient levels of IgA and IgE immunoglobulins, the natural
infection fighting agents in the blood, children with A-T are
highly susceptible to lung infections that do not respond to
typical antibiotic treatments. For these A-T patients, the
combination of a weakened immune system and the progressive
ataxia can ultimately lead to pneumonia as a common cause of
death.
Predisposition to
Cancer...
Children with A-T tend to develop malignancies of the blood
system almost 1,000 times more frequently than the general
population. Lymphoma and leukemia are particularly common
types of cancer, although the frequencies of most cancers are
elevated. Ironically, another facet of the disease is an
extreme sensitivity to radiation, which means that A-T
patients cannot tolerate the therapeutic radiation usually
given to cancer patients.
Other Features of
A-T...
Other features of ataxia-telangiectasia that may affect some
children are: mild diabetes mellitus, premature graying of the
hair, difficulty swallowing causing choking and/or drooling
and slowed growth. Even though A-T is a multi-system disorder,
the children afflicted have and maintain normal or even
above-normal intelligence. Their dispositions seem to remain
equable and help them to maintain a healthy outlook on life
despite the progression of their disabilities.
How Frequent is
A-T?
Ataxia-telangiectasia respects no racial, economic, geographic
or education barriers. Both males and females are equally
affected. Epidemiologists estimate the frequency of A-T as 1
in 40,000 births. But it is believed that many children with
A-T, particularly those who die at a young age, are never
properly diagnosed. Therefore, this disease may actually be
much more common.
The Prognosis...
A-T is presently incurable and unrelenting. If they are lucky
enough not to develop cancer, most A-T children are dependent
on wheelchairs by the age of ten, not because their muscles
are too weak, but because they cannot control them. Later, A-T
patients usually die from respiratory failure or cancer by
their teens or early twenties. A few A-T patients live into
their forties, but they are extremely rare.
What treatments
are available?
There is no cure for A-T, and there is currently no way to
slow the progression of the disease. At this time, treatments
are directed only toward partially alleviating some symptoms
as they appear. Because A-T is a rare, "orphan" disease, very
little research data is available on pharmaceutical therapies
that may aid these children. Physical, occupational and speech
therapy are used to help maintain flexibility, gamma-globulin
injections help supplement the immune systems of A-T patients,
and high-dose vitamin regimes are being undertaken with some
moderate results.
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