Genetic predispositions and childhood cancer.

This article provides an overview of the problem of genetic susceptibility to childhood cancer with a particular emphasis on problems with ascertaining inherited cancer risk and the role of tumor-suppressor gene mutations in cancer predispositions. The association between neurofibromatosis type 1 and childhood leukemia is used to illustrate some of the issues faced by molecular biologists and genetic epidemiologists in identifying and analyzing at-risk individuals. The problem of incomplete penetrance in cancer susceptibility is presented and potential models are discussed. The article concludes with a number of tentative conclusions from existing data and speculations for future studies.