TP53 rs1042522: p53 Function, Cancer, and Longevity

6 days ago

4 min read

When a cell’s DNA becomes damaged, continuing to divide can pass that damage to new cells. The TP53 gene produces p53, a protein that helps coordinate the response: slowing cell division, supporting repair, or triggering the removal of cells with damage that cannot be resolved [R]. This protective role has earned p53 the nickname “guardian of the genome.”

A common variant, TP53 rs1042522, changes one amino acid in the protein. Its two forms—Arg72 and Pro72—differ in how they influence programmed cell death and cell-cycle control. Researchers have also investigated whether those differences translate into changes in cancer susceptibility or longevity [R, R].

You can explore your result in the free TP53 GeneExplorer report.

This article uses forward-strand genotypes: CC = Arg/Arg, CG = Arg/Pro, and GG = Pro/Pro.

(Most consumer raw DNA files use forward-strand)

Masked elderly man in a red sweater stands with a cane by open windows in a bright hallway, gazing outside.

What Does the TP53 Gene Do?

P53 helps prevent damaged cells from multiplying.

It acts as a transcription factor, meaning it regulates the activity of other genes. When cellular stress activates this system, p53 can help coordinate several responses:

Cell-cycle arrest: pausing cell division to allow time for repairs.
DNA repair: activating genes involved in responding to damaged DNA.
Apoptosis: initiating programmed cell death when damage is too severe.

These responses help maintain the integrity of tissues and limit uncontrolled cell growth [R].

For related protective mechanisms, explore BRCA1 and DNA repair and APC and cell-growth regulation.

What Is TP53 rs1042522?

Rs1042522 changes the amino acid at position 72 of p53:

Arg72 contains arginine.
Pro72 contains proline.

You may see the variant called Arg72Pro, Pro72Arg, R72P, or P72R, depending on the reference form being described.

On the forward strand, C corresponds to Arg72 and G corresponds to Pro72. Some publications use coding-strand letters, so the amino-acid names are useful when comparing sources [R]. This is a common missense variant: it changes the protein’s sequence, with experimentally observed effects on its behavior.

CC, CG, and GG: What Do the Genotypes Mean?

The clearest differences concern how the two protein forms respond in laboratory experiments.

Forward-strand genotype	Protein forms	Main experimental finding
CC	Arg/Arg	Arg72 triggers programmed cell death more efficiently than Pro72.
CG	Arg/Pro	Carries both forms; an exact halfway response is not established.
GG	Pro/Pro	Pro72 produces stronger cell-cycle arrest than Arg72 in experimental comparisons.

Sources: [R, R].

Arg72 and Programmed Cell Death

A 2003 study compared the Arg72 and Pro72 forms using experimental cell systems.

Researchers found that Arg72 induced apoptosis more efficiently. One explanation involved its greater ability to reach the mitochondria, structures that participate in the machinery of programmed cell death.

This mitochondrial localization was accompanied by the release of cytochrome c, a protein involved in activating the apoptotic response [R]. The finding provides a concrete biological mechanism: a single amino-acid difference can affect how p53 engages the cell’s self-removal machinery.

Pro72 and Pausing Cell Division

A separate study examined how the two forms affected cell-cycle progression.

Again, Arg72 was more efficient at inducing apoptosis. However, Pro72 produced greater arrest in the G1 phase, a checkpoint before cells replicate their DNA [R]. This creates an interesting contrast between two responses to cellular stress:

Arg72 more readily activates cell death, while Pro72 more strongly pauses cell division in these experiments.

It does not establish that GG individuals repair all DNA damage more effectively, or that CC individuals are universally better protected against cancer. Those broader outcomes require evidence from human studies.

Does TP53 rs1042522 Affect Longevity?

An early Danish study produced a striking result.

Published in 2007, it followed 9,219 people aged 20–95. Researchers reported approximately three years longer median survival for Pro/Pro individuals compared with Arg/Arg individuals—GG versus CC in forward-strand notation. The study also found better survival after cancer or other life-threatening diseases, but did not find a corresponding reduction in cancer risk [R].

The proposed association concerned survival, rather than simply avoiding cancer.

However, a much larger study later tested the idea.

What Did the Study of 105,200 People Find?

A 2017 Danish study examined 105,200 people from the Copenhagen General Population Study.

It found no overall association between rs1042522 and cancer incidence, mortality after cancer, or all-cause mortality.

For Pro/Pro versus Arg/Arg, the hazard ratio for all-cause mortality was 1.09, with a 95% confidence interval of 0.98–1.21. This did not demonstrate a survival advantage [R]. The larger study therefore did not reproduce the earlier longevity finding.

Is This a Cancer-Causing TP53 Variant?

Rs1042522 is a common functional variant, rather than a Li-Fraumeni syndrome–causing pathogenic variant. ClinVar lists the codon-72 polymorphism as benign [R]. Other inherited pathogenic variants in TP53 can cause Li-Fraumeni syndrome, a condition associated with substantially increased susceptibility to several cancers.

Separately, TP53 changes can arise during life within tumor cells. Those acquired changes are different from checking this common inherited marker in a consumer DNA file [R].

Checking rs1042522 does not screen for all inherited TP53 conditions or identify changes occurring inside a tumor.

What Your TP53 Result Means for You

Your genotype offers a window into an important cellular decision: whether to pause division or activate programmed cell death after stress.

CC: carries two copies encoding the Arg72 form.
CG: carries one copy encoding each form.
GG: carries two copies encoding the Pro72 form.

The research supports differences between these protein forms. It does not provide a reliable individual cancer-risk percentage or lifespan prediction.

Explore Your TP53 Result in GeneExplorer

TP53 connects DNA damage, cell-cycle checkpoints, and the removal of damaged cells. Rs1042522 makes that biology tangible through two common forms of one of the body’s most studied protective proteins.

Visit the free TP53 GeneExplorer report to explore your CC, CG, or GG result. You can analyze your existing raw DNA file in your browser to check whether this marker is available.