What are the genetic changes related to Li-Fraumeni syndrome ?
The CHEK2 and TP53 genes are associated with Li-Fraumeni syndrome.  More than half of all families with Li-Fraumeni syndrome have inherited mutations in the TP53 gene. TP53 is a tumor suppressor gene, which means that it normally helps control the growth and division of cells. Mutations in this gene can allow cells to divide in an uncontrolled way and form tumors. Other genetic and environmental factors are also likely to affect the risk of cancer in people with TP53 mutations.  A few families with cancers characteristic of Li-Fraumeni syndrome and Li-Fraumeni-like syndrome do not have TP53 mutations, but have mutations in the CHEK2 gene. Like the TP53 gene, CHEK2 is a tumor suppressor gene. Researchers are uncertain whether CHEK2 mutations actually cause these conditions or are merely associated with an increased risk of certain cancers (including breast cancer).