Diagnosing Li-Fraumeni Syndrome (LFS)
Diagnosing Li-Fraumeni Syndrome (LFS) involves a combination of clinical criteria, family history, and genetic testing. The diagnosis is typically considered when an individual or family meets specific criteria indicating a higher risk of LFS.
Clinical Criteria for LFS Diagnosis
The classic clinical criteria for LFS, known as the Chompret criteria, include:
- Proband (Individual with Cancer): A person with a sarcoma diagnosed before age 45.
- Family History: A first-degree relative with any cancer before age 45, and another first-degree or second-degree relative with any cancer before age 45 or a sarcoma at any age.
Revised Chompret Criteria
The revised Chompret criteria expand the diagnostic possibilities to include:
- Individual with ACC, Choroid Plexus Carcinoma, or Anaplastic Rhabdomyosarcoma: Regardless of family history.
- Individual with Multiple Primary Cancers: Two or more cancers, with the first diagnosed before age 36.
- Individual with Cancer Before Age 20: With a first-degree relative with any LFS-related cancer before age 45.
- Individual with Cancer Before Age 45: With a first-degree relative with any cancer before age 45, and another first- or second-degree relative with any cancer at any age.
For more detailed information on diagnostic criteria, visit our Li-Fraumeni Syndrome resource.
Genetic Testing for TP53 Mutations
Genetic testing for TP53 mutations is the definitive way to confirm an LFS diagnosis. Testing is typically recommended for individuals who meet the clinical criteria.
- Blood Sample: DNA is extracted from a blood sample and analyzed for TP53 mutations.
- Variant Interpretation: Identifying and interpreting the significance of any detected mutations.
Genetic Counseling
Genetic counseling is an essential part of the diagnostic process. A genetic counselor can:
- Assess Family History: Evaluate the family’s cancer history to determine the likelihood of LFS.
- Explain Genetic Testing: Provide information about the benefits, risks, and limitations of genetic testing.
- Interpret Results: Explain the results of genetic testing and their implications.
In summary, diagnosing Li-Fraumeni Syndrome involves clinical criteria, family history, and genetic testing for TP53 mutations. Genetic counseling is crucial for understanding the risks and implications of LFS.
