Germline TP53 mutations are associated with Li-Fraumeni syndrome(LFS), a disease that predisposes carriers to a wide variety of early onset tumors.In southern and southeastern Brazil, a high frequency of a germlineTP53 mutation, p.R337H, was diagnosed in 0,3% of the populationdue to a founder effect. This evidence concerns the gene TP53 and Li-Fraumeni syndrome.