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PubMed This is a summary of 9 peer-reviewed journal articles Updated
Genetics

Diagnosis, Criteria, and Genetic Testing for LFS

At a Glance

Li-Fraumeni Syndrome (LFS) is diagnosed through genetic testing for an inherited TP53 gene mutation. Doctors use family history guidelines like the Chompret criteria to determine who should be tested, often using skin biopsies to prevent false positives from age-related blood changes.

Getting a diagnosis for Li-Fraumeni Syndrome (LFS) is a multi-step process that often begins with a family history and ends with a precise genetic test.

The Rules of Diagnosis: Classic vs. Chompret

Historically, doctors only tested people who met very strict family history rules, known as the Classic LFS criteria. To meet these, a person had to have a sarcoma before age 45, a parent or sibling with a cancer before age 45, and another close relative with an early-onset cancer [1].

To catch more families at risk, experts developed the Revised Chompret Criteria. You might be referred for genetic testing if you meet any of the following [1][2]:

  • A “core” tumor (like a sarcoma, brain tumor, or breast cancer) before age 46, plus a relative with an LFS tumor before age 56.
  • Multiple tumors that belong to the LFS spectrum, with the first one occurring before age 46.
  • Specific rare tumors, such as adrenocortical carcinoma (ACC) or choroid plexus carcinoma, diagnosed at any age.
  • Early-onset breast cancer diagnosed before the age of 31.

How Genetic Testing Works

The goal of testing is to find a germline mutation—a change in the TP53 gene that was present at birth and is in every cell of your body [3]. Testing is usually done using a blood or saliva sample [3].

In some cases, doctors may recommend a skin punch biopsy. This involves taking a tiny piece of skin to test the DNA in skin cells (fibroblasts). This is the most reliable way to confirm the mutation is truly “germline” and not just present in the blood [4][5].

A Technical Hurdle: What is CHIP?

One complexity in LFS testing is a phenomenon called Clonal Hematopoiesis of Indeterminate Potential (CHIP) [6]. As people age, their blood cells can naturally develop mutations that are not present in the rest of their body. If a TP53 mutation shows up in a blood test but is actually just a result of CHIP, it is not LFS. This is a common cause of “false positive” LFS diagnoses, which is why skin biopsies are so important for accuracy [7][4].

Cascade Testing: Protecting the Family

If you are found to have a TP53 mutation, your doctor will recommend cascade testing [8]. This is the process of testing your first-degree relatives for that same specific mutation [3].

Because many LFS-related cancers can happen in infancy or early childhood, the medical consensus strongly supports testing children from birth [9][8]. Finding a mutation in a relative allows them to start intensive surveillance, which can catch cancers early when they are most curable [8][3].

Family Planning and Reproductive Options

Knowing you have a 50% chance of passing the mutation to your children can be deeply distressing. However, there are family planning options available. Many patients choose to undergo In Vitro Fertilization (IVF) combined with Preimplantation Genetic Testing for Monogenic/Single Gene Defects (PGT-M). This process allows doctors to test embryos for the TP53 mutation and select only those without the mutation for pregnancy, empowering you to have children who will not inherit LFS [9].

Common questions in this guide

What are the Chompret criteria for Li-Fraumeni Syndrome?
The Revised Chompret criteria are guidelines doctors use to decide who should receive genetic testing for LFS. You might be referred if you have early-onset breast cancer before age 31, specific rare tumors like adrenocortical carcinoma, or multiple LFS-related cancers in your family.
Why might my doctor recommend a skin biopsy for LFS testing?
While genetic testing often starts with a blood or saliva test, a skin biopsy is the most reliable way to confirm an LFS diagnosis. It proves the TP53 mutation is present in all your body's cells, rather than being a false positive caused by natural blood changes.
What is a CHIP false positive in TP53 testing?
Clonal Hematopoiesis of Indeterminate Potential (CHIP) occurs when blood cells naturally develop mutations as you age. If a blood test detects a TP53 mutation caused by CHIP rather than a true inherited mutation, it can result in a false positive LFS diagnosis.
What is cascade testing for LFS?
Cascade testing is the process of offering genetic testing to the parents, siblings, and children of someone recently diagnosed with LFS. Because LFS-related cancers can occur in infancy, testing children at birth allows them to start life-saving cancer screenings early.
Can I have children without passing on Li-Fraumeni Syndrome?
Yes, many individuals with LFS use family planning options like In Vitro Fertilization (IVF). Doctors can use a process called preimplantation genetic testing to screen embryos and select those without the TP53 mutation for pregnancy.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my family history and current age, do I meet the 'Classic' or the 'Revised Chompret' criteria?
  2. 2.If my genetic test was done on blood, how can we be sure the result isn't a false positive from 'CHIP' (clonal hematopoiesis)?
  3. 3.Would you recommend a skin biopsy to confirm if this mutation is truly germline (present in every cell of my body)?
  4. 4.At what age should my children begin testing, and which specific screenings will they start first?
  5. 5.Can you refer us to a genetic counselor who can help coordinate testing for my other relatives?

Questions For You

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References

References (9)
  1. 1

    Clinical and molecular characterization of patients fulfilling Chompret criteria for Li-Fraumeni syndrome in Southern Brazil.

    Matzenbacher Bittar C, de Araújo Rocha YM, Vieira IA, et al.

    PloS one 2021; (16(9)):e0251639 doi:10.1371/journal.pone.0251639.

    PMID: 34529667
  2. 2

    Medical guidelines for Li-Fraumeni syndrome 2019, version 1.1.

    Kumamoto T, Yamazaki F, Nakano Y, et al.

    International journal of clinical oncology 2021; (26(12)):2161-2178 doi:10.1007/s10147-021-02011-w.

    PMID: 34633580
  3. 3

    Li-Fraumeni syndrome in Tunisian carriers with different and rare tumor phenotype: genotype-phenotype correlation.

    Sassi H, Meddeb R, Cherif MA, et al.

    BMC medical genomics 2022; (15(1)):44 doi:10.1186/s12920-022-01189-w.

    PMID: 35246108
  4. 4

    Standardized Culture of Skin Fibroblasts From Punch Biopsies for Germline DNA Isolation in Myeloid Malignancies: A Practical Bedside-to-Laboratory Approach.

    Kour P, Kumari N, Kaushal N, et al.

    Bio-protocol 2025; (15(19)):e5469 doi:10.21769/BioProtoc.5469.

    PMID: 41080449
  5. 5

    Myelodysplastic syndrome diagnosed by genetic testing for hereditary cancer: a case report.

    Ridd S, Peck L, Bankar A, et al.

    NPJ genomic medicine 2025; (10(1)):39 doi:10.1038/s41525-025-00476-6.

    PMID: 40368914
  6. 6

    How Great Is the Threat of Clonal Hematopoiesis? Let This New Risk Score Be Your Guide.

    Xie Z, DeZern AE

    NEJM evidence 2023; (2(5)):EVIDe2300053 doi:10.1056/EVIDe2300053.

    PMID: 38320009
  7. 7

    TP53 germline testing and hereditary cancer: how somatic events and clinical criteria affect variant detection rate.

    Rofes P, Castillo-Manzano C, Menéndez M, et al.

    Genome medicine 2025; (17(1)):3 doi:10.1186/s13073-025-01429-5.

    PMID: 39810221
  8. 8

    Mutation screening of germline TP53 mutations in high-risk Chinese breast cancer patients.

    Kwong A, Shin VY, Ho CYS, et al.

    BMC cancer 2020; (20(1)):1053 doi:10.1186/s12885-020-07476-y.

    PMID: 33138793
  9. 9

    Reply to Kratz et al.

    Frebourg T, Lagercrantz SB, Oliveira C, et al.

    European journal of human genetics : EJHG 2020; (28(11)):1483-1485 doi:10.1038/s41431-020-00710-y.

    PMID: 32792624

This page explains Li-Fraumeni Syndrome diagnosis and genetic testing for educational purposes. Your genetic counselor and oncologist are the best sources for interpreting your specific family history and test results.

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