[Hereditary tumor syndrome: of its concept and classification]

With the cloning of cancer-predisposing genes many responsible genes have been identified from hereditary tumor syndrome over the past 10 years. Cancer is a genetic disease, arising from accumulation of mutations that promote clonal selection of cells and tumor progression. An individual who carries a mutant allele of an inherited cancer gene has a variable cancer risk. The proteins encoded by inherited cancer genes have been implicated in diverse cellular function, including proliferation, differentiation, apoptosis, and maintenance of genomic integrity. Concept and classification of hereditary tumor syndrome are discussed from genetic aspect.