Ataxia-telangiectasia or Louis-Bar syndrome.

Ataxia-telangiectasia (A-T) is a clinical syndrome that commonly shows oculocutaneous telangiectasia, progressive cerebellar ataxia, recurrent sinopulmonary infections, increased incidence of malignancy, x-ray hypersensitivity, and autosomal recessive inheritance. Profound dysfunction of both humoral and cell-mediated immune systems is demonstrated by low IgA levels, an immature thymus, a poor response to antigenic challenges, and recurrent infections. The high risk of malignancy may be related to poor immune surveillance. Two cases (sisters) are reported demonstrating the typical features of the disease along with the results of a trial of the immunopotentiating drug, levamisole, in one of them. The features of A-T are reviewed and include the more recent findings of elevated serum carcinofetal proteins and chromosomal aberrations.