Meyahealth
HomeGeneticsGeneTP53 gene
Back to Gene
TP53 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

TP53 gene

The TP53 gene acts as a "guardian of the genome" by producing a tumor suppressor protein that regulates cell division and repairs damaged DNA.

Normal Function

The TP53 gene provides instructions for making a protein called tumor protein p53 (or p53). This protein acts as a tumor suppressor, which means that it regulates cell division by keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way.

The p53 protein is located in the nucleus of cells throughout the body, where it attaches (binds) directly to DNA. When the DNA in a cell becomes damaged by agents such as toxic chemicals, radiation, or ultraviolet (UV) rays from sunlight, this protein plays a critical role in determining whether the DNA will be repaired or the damaged cell will self-destruct (undergo apoptosis). If the DNA can be repaired, p53 activates other genes to fix the damage. If the DNA cannot be repaired, this protein prevents the cell from dividing and signals it to undergo apoptosis. By stopping cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors.

Health Conditions Related to Genetic Changes

Li-Fraumeni syndrome

Although somatic mutations in the TP53 gene are found in many types of cancer, Li-Fraumeni syndrome appears to be the only cancer syndrome associated with inherited mutations in this gene. This condition greatly increases the risk of developing several types of cancer, including breast cancer; bone cancer; and cancers of soft tissues (such as muscle) called soft tissue sarcomas, particularly in children and young adults.

Breast, Bladder, and Other Cancers

Noninherited (somatic) mutations in the TP53 gene are common in many cancers, including breast, bladder, lung, ovarian, and head and neck squamous cell carcinomas. These mutations are acquired during a person's lifetime and are present only in cells that become cancerous. Most of these mutations change single amino acids in the p53 protein, which reduces or eliminates the protein's tumor suppressor function. This altered p53 protein cannot regulate cell proliferation effectively, leading to the accumulation of DNA damage and uncontrolled tumor growth.

Frequently Asked Questions

If you have an inherited TP53 mutation, each of your children has a 50% chance of inheriting the same mutation. Since Li-Fraumeni syndrome is an autosomal dominant condition, inheriting even one copy of the mutated gene is sufficient to significantly increase their lifetime risk of developing various cancers. Genetic counseling is highly recommended for families to discuss these risks and potential screening for children.
Individuals with Li-Fraumeni syndrome typically follow a rigorous cancer surveillance protocol, often referred to as the "Toronto Protocol" or similar guidelines. This usually includes annual whole-body MRI scans, annual brain MRI scans, regular dermatologic exams, colonoscopies, and for women, annual mammograms and breast MRIs starting at a young age. Specific screenings may vary based on age and family history, and should be discussed with an oncologist or genetic counselor.
Li-Fraumeni syndrome is primarily diagnosed through genetic testing for inherited mutations in the TP53 gene. This testing is often recommended for individuals who meet specific clinical criteria, such as having multiple family members with early-onset cancers (especially breast cancer, sarcomas, brain tumors, or adrenal cortical carcinoma), or an individual diagnosed with certain cancers at a young age. Genetic counseling is an important step before and after testing.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

Meyahealth

Ⓒ 2026. All rights reserved by MEYA

About UsTerms & PolicyFAQ