Li Fraumeni syndrome is genetic condition that increases the chances of a person developing certain cancers over a lifetime. Some of the types of cancer seen in Li Fraumeni syndrome are soft tissue sarcomas, breast cancer, and osteosarcomas (cancer of bone cells). Most of the cancers associated with Li Fraumeni syndrome appear in late childhood and early teenage years. Li Fraumeni syndrome is caused by changes (mutations) in either the CHEK2 gene or TP53 gene. These genes are known as tumor suppressor genes, which are genes that help protect the body from cancer by making sure cells divide in a controlled way. When tumor suppressor genes are not working properly, cell division and growth is not controlled, leading to the cancers seen in Li Fraumeni syndrome.
Li Fraumeni syndrome is inherited in an autosomal dominant manner. People have two copies of most genes in their body, including CHEK2 and TP53. People with Li Fraumeni syndrome are born with a mutation in only one of the two CHEK2 or TP53 gene copies they have. This means they have only one copy of the gene that works in all of their cells. If at some point in their life the other copy of the gene becomes mutated in a cell, which can happen randomly, that person will no longer have a working copy of the gene. This occurrence is what leads to the start of cancer in whatever tissue the cell is located in.
Li Fraumeni syndrome is suspected in a person who has one of the related cancers at a young age, usually before the age of 50 years, as well as a family history of related cancers. The diagnosis is confirmed with genetic testing. Aggressive screening, including imaging and blood studies, are recommended to identify cancer at an early stage in people with Li Fraumeni syndrome. If your child has been diagnosed with Li Fraumeni syndrome, talk with their doctor to discuss treatment and screening recommendations. Support groups can help connect you with other affected families.