Li-Fraumeni syndrome
Li-Fraumeni syndrome is an autosomal dominant cancer predisposition syndrome caused by a germline TP53 mutation, producing early-onset, often multiple cancers: soft tissue and bone sarcomas, breast cancer, brain tumors, adrenocortical carcinoma, and leukemia. It is suspected from a personal and three-generation family pattern of these tumors, confirmed by germline TP53 testing after genetic counseling, and managed by annual breast MRI starting at age 20 to 25, prompt evaluation of new symptoms, risk-reducing surgery counseling, and testing of at-risk relatives.
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What this article covers
- Overview
Definition: Li-Fraumeni syndrome is a rare, autosomal dominant cancer predisposition syndrome caused by a germline mutation in the TP53 tumor suppressor gene on chromosome 17.
- Epidemiology
Rare syndrome with dominant transmission: each child of a carrier has a 50% risk of inheriting the variant, so the pedigree typically shows affected members in successive generations.
- Risk factors
Germline TP53 mutation: the defining and only causal factor; one inherited mutant copy is sufficient for the cancer-prone phenotype.
- Pathophysiology
Loss of the G1 checkpoint: p53 normally responds to DNA damage by halting the cell cycle to allow repair and triggering apoptosis if damage is irreparable; loss of function lets cells with damaged DNA survive and proliferate.
- Clinical features
Recognition pattern (hallmark): early-onset cancer, multiple primary cancers in one person (concurrent or sequential), or clustering of the core tumors across relatives in successive generations should suggest the syndrome.
- Differential diagnosis
Hereditary breast and ovarian cancer (BRCA1/2): breast and ovarian cancer with pancreatic and prostate cancer, but not childhood sarcomas, adrenocortical carcinoma, or brain tumors (BRCA mutations).
- Diagnosis
How the diagnosis is established: Li-Fraumeni syndrome is confirmed by identifying a germline pathogenic TP53 variant on genetic testing; no clinical scoring system is required, and the clinical…
- Management
First, confirm the variant and complete counseling, then build a lifelong surveillance and early-evaluation plan with oncology and genetics.
- Complications
Multiple primary cancers: carriers frequently develop concurrent or sequential malignancies, so a treated cancer does not end risk.
- Prognosis
Prognosis is driven by the cancers that develop, and the early age and multiplicity of tumors make lifetime cancer burden high.
- Prevention
Breast cancer surveillance: annual breast MRI with or without mammography starting at age 20 to 25 in women who carry a TP53 variant.
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