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At a glance

Heredofamilial Neurocutaneous Progressive Syndrome characterized by cerebellar ataxia (early childhood), oculocutaneous telangiectasia (adolescence), and impairment of the immune system. Recurrent infections of the lung (pulmonary restrictive disease) and sinuses are frequent. The onset of the symptoms most often first appears in during the toddler stage when the child begins to walk.


Ataxia Telangiectasia Syndrome.


Described by Denise Louis-Bar, a Belgian neuropathologist, in 1941.


In the United States, the prevalence is estimated approximately one in 40,000 to 100,000 live births. Males and females may be affected in equal numbers. Ataxia telangiectasia usually begins during infancy (between 1 and 3 years of age) and often affects more than one child in a family.

Genetic inheritance

Autosomal recessive. The ataxia telangiectasia (AT) gene has been localized to chromosome 11q23.


Ataxia telangiectasia is a syndrome with multiorgan involvement. Pathophysiology cannot be explained by a single cellular mechanism. Neurologic: Cerebellar dysfunction, progressive neurologic deterioration, developmental delay; mucocutaneous: telangiectasia on conjunctiva and exposed areas; endocrine: glucose intolerance, hypogonadism.


Based on clinical features. Immunodeficiency is present and is evidenced by low or absent IgA and IgE and atypical IgM. There is a slight elevation of liver enzymes in 50% of patients. May have raised α-fetoprotein. Glucose intolerance and hypogonadism particularly is usually seen in females. Marked progressive cerebellar atrophy usually is demonstrated early by CT scan or MRI and characteristically defined as enlarged cerebellar sulci and cisterns and fourth ventricle.

Clinical aspects

Initial presentation usually is neurologic as evidenced by problems with development of walking, oculomotor abnormalities, and progressive neurologic disability. There is a significant risk of recurrent pulmonary aspiration of oral secretions. In addition to telangiectasia, vitiligo café-au-lait spots, and premature graying may be present. An absence of secondary sexual characters is seen in females. Elevated liver enzymes associated with fatty infiltration of the liver. Ataxia telangiectasia patients are at increased risk for developing malignancies particularly lymphoma and leukemia in children and gastric carcinoma in adults. Chronic respiratory infections and bronchiectasis, unresponsive to antibiotics, are frequently the ultimate cause of death. It is unusual to survive beyond the third decade.

Louis-Bar Syndrome: Ocular telangiectasias in a patient with ataxia telangiectasia.

Louis-Bar Syndrome: Similar telangiectases in Louis-Bar Syndrome can also be found on the ear.

Precautions before anesthesia

Neurologic evaluation, particularly cerebellar and bulbar function. Evaluate pulmonary and cardiac function in light of chronic lung disease. Objective evaluation of respiratory ...

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