Incidence of Cancer in 161 Families Affected by Ataxia–Telangiectasia

Abstract
Ataxia—telangiectasia is an autosomal recessive syndrome in which cancers develop in affected homozygotes at a rate approximately 100 times higher than in unaffected age—matched subjects. Retrospective studies have shown that persons heterozygous for the ataxia—telangiectasia gene, who make up about 1 percent of the general population, also have an excess risk of cancer, particularly breast cancer in women. Patients with ataxia—telangiectasia and cells derived from homozygotes and heterozygotes are unusually sensitive to ionizing radiation.