GENETIC PREDISPOSITION TO CHILDHOOD-CANCE R

Most pediatric cancers occur sporadically. In 5% to 15% of cases, howe ver, a genetic predisposition is suggested by the presence of an inher ited disease or congenital defect, or by a family history of early can cer. The clinical and molecular characteristics of the main syndromes associated with an increased risk of childhood cancer are reviewed. Nu merous genes involved in carcinogenesis and in the regulation of norma l cell growth and differentiation have been identified. In some cases, elucidation of the molecular mechanisms of syndromes associated with childhood cancer has allowed to develop tests for detecting high-risk individuals. The use of these tests raises complex medical, psychologi cal, and ethical issues.