In children with ataxia-telangiectasia, incoordination usually develops when they begin to walk, and muscles progressively weaken, causing them to be greatly disabled.
Doctors do blood tests to diagnose the disorder.
Treatment involves antibiotics (to prevent infections) and immune globulin.
(See also Overview of Immunodeficiency Disorders Overview of Immunodeficiency Disorders Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more .)
Ataxia-telangiectasia is a primary immunodeficiency disorder Primary immunodeficiency Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more . It is usually inherited as an autosomal (not sex-linked) recessive Inheritance of Single-Gene Disorders Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body or code for functional RNA molecules.... read more disorder. That is, two genes for the disorder, one from each parent, are required.
The increased susceptibility to infections in people with ataxia-telangiectasia results from malfunction of B cells B cells One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more 
and T cells T cells One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more (lymphocytes), which help the body defend itself against microorganisms and development of abnormal cells that can lead to cancer. Often, levels of certain types (classes) of antibodies Antibodies One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more (immunoglobulins)—IgA and IgE—are also low.
Ataxia-telangiectasia also causes abnormalities in the cerebellum (the part of the brain that coordinates the body’s movements), which are unrelated to the immunodeficiency disorder and which result in loss of coordination.
Symptoms of Ataxia-Telangiectasia
Incoordination (ataxia) usually develops when children begin to walk, but it may be delayed until age 4. Speech becomes slurred, and muscles progressively weaken, leading to severe disability. Intellectual disability may develop and progress.
Between the ages of 1 and 6 (but often not until age 4), capillaries in the skin and eyes become dilated and visible. The dilated capillaries (telangiectasia), called spider veins, are usually most obvious on the eyeballs, ears, and sides of the neck.
The endocrine system Endocrine Glands The endocrine system consists of a group of glands and organs that regulate and control various body functions by producing and secreting hormones. Hormones are chemical substances that affect... read more may be affected, resulting in small testes (in boys), infertility Overview of Infertility Infertility is usually defined as the inability to achieve a pregnancy after 1 year of regular sexual intercourse without birth control. Frequent intercourse without birth control usually results... read more 
, and diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Symptoms of diabetes may... read more .
Sinus and lung infections recur, often leading to pneumonia Pneumonia in Immunocompromised People Pneumonia is infection of the lungs. Pneumonia in people whose immune system is weakened or impaired (for example, by acquired immunodeficiency syndrome [AIDS], cancer, organ transplantation... read more and chronic lung disorders such as bronchiectasis Bronchiectasis Bronchiectasis is an irreversible widening (dilation) of portions of the breathing tubes or airways (bronchi) resulting from damage to the airway wall. The most common cause is severe or repeated... read more (irreversible widening due to chronic inflammation of the airways).
The risk of cancer, especially leukemia Overview of Leukemia Leukemias are cancers of white blood cells or of cells that develop into white blood cells. White blood cells develop from stem cells in the bone marrow. Sometimes the development goes awry... read more , lymphoma Overview of Lymphoma Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs. Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These... read more 
, brain tumors Overview of Brain Tumors A brain tumor can be a noncancerous (benign) or cancerous (malignant) growth in the brain. It may originate in the brain or have spread (metastasized) to the brain from another part of the body... read more , and stomach cancer Stomach Cancer A Helicobacter pylori infection is a major risk factor for stomach cancer. Vague abdominal discomfort, weight loss, and weakness are some typical symptoms. Diagnosis includes endoscopy... read more 
, is increased.
Ataxia-telangiectasia usually progresses to paralysis, dementia, and death, typically by age 30.
Diagnosis of Ataxia-Telangiectasia
Blood tests
Genetic testing
Doctors suspect ataxia-telangiectasia based on symptoms.
Blood tests to measure the levels of IgA, and genetic tests can help confirm the diagnosis.
If doctors suspect endocrine disorders or cancers based on results of their examination, tests to check for these disorders are done.
Treatment of Ataxia-Telangiectasia
Antibiotics and immune globulin
To help prevent infections, doctors give people antibiotics and immune globulin (antibodies obtained from the blood of people with a normal immune system), which provides the missing immunoglobulins. Immune globulin may be injected into a vein (intravenously) once a month or under the skin (subcutaneously) once a week or once a month.
However, these drugs do not relieve the other problems.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Immune Deficiency Foundation: Ataxia-telangiectasia: General information on ataxia-telangiectasia, including information on diagnosis and treatment
