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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.

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.

Ataxia Telangiectasia Syndrome.

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

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 as evidenced by low or absent IgA and IgE and atypical IgM. Slight elevation of liver enzymes in 50% of patients. May have raised α-fetoprotein. Glucose intolerance and hypogonadism particularly 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.

Initial presentation usually is neurologic as evidenced by problems with development of walking, oculomotor abnormalities, and progressive neurologic disability. Risk of recurrent aspiration of oral secretions. In addition to telangiectasia, vitiligo, café-au-lait spots, and premature graying may be present. Absence of secondary sexual characteristics 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. Unusual to survive beyond the third decade.

Neurologic evaluation, particularly cerebellar and bulbar function. Evaluate pulmonary and cardiac function in light of chronic lung disease. Objective evaluation of respiratory system may be difficult because of neurologic disease. Hematologic evaluation should look for malignancies that may result in pancytopenia, requiring blood or platelet transfusions preoperatively. Evaluation of hepatic function, glucose homeostasis, and coagulation profile.

Patient cooperation may be limited because of mental deficiency. Ventilation/oxygenation may be challenging because of chronic lung disease. May need postoperative ventilation. Increased risk of aspiration because of neurologic disease. Although there are no known direct cardiac anomalies, the presence of chronic lung disease and the potential effect of increased pulmonary vascular resistance on cardiac function must be evaluated.

Drugs that depend on hepatic metabolism should be used with care in the presence of hepatic dysfunction. Use muscle relaxants judiciously in presence of progressive neurologic disease.

Jones KL: Ataxia telangiectasia syndrome, in Lyons K (ed): ...

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