Li–Fraumeni syndrome (LFS) is a rare, autosomal dominant, hereditary disorder[1] that predisposes carriers to cancer development.

It was named after two American physicians, Frederick Pei Li and Joseph F. Fraumeni Jr., who first recognized the syndrome after reviewing the medical records and death certificates of childhood rhabdomyosarcoma patients.

If these DNA mutations are left unchecked, some cells can divide uncontrollably, forming tumors (cancers).

[10] These missense mutations cause a decrease in the ability of p53 to bind to DNA, thus inhibiting the normal TP53 mechanism.

[10] LFS-L individuals generally do not have any detectable TP53 variants, and tend to meet either the Birch or Eeles criteria.

[18] People with LFS require early and regular cancer screening following the "Toronto Protocol":[18][19][20]