Epidemiological factors related to the malignant neoplasms in ataxia-telangiectasia families

In response to the demonstration of an increased risk of death from specific neoplasms among the blood relatives of patients homozygous for ataxia-telangiectasia (A-T) a review of the epidemiology of selected neoplasms and its application to the A-T relatives' mortality experience has been presented. Demographic, social and medical factors associated with cancers of the gall bladder and bile ducts, ovary and stomach do not explain either the increased number or the unusually early age of onset of these malignancies observed among the A-T family members. Although this analysis is limited in scope and reflects a univariate approach to the etiology of the various cancers considered, it supports a genetic basis for an increased susceptibility to malignant neoplasms among A-T heterozygotes.