TP53 encodes the p53 protein, a critical tumor suppressor that acts as a transcription factor to protect cells from damage. When activated by cellular stress such as DNA damage, p53 triggers responses including DNA repair, cell cycle arrest, and programmed cell death (apoptosis) to prevent the propagation of damaged cells. TP53 is the most frequently mutated gene in human cancers, and loss of its function contributes to tumor development, invasion, drug resistance, and genomic instability. Inherited mutations in TP53 cause Li-Fraumeni syndrome, a rare hereditary condition that greatly increases the risk of developing multiple types of cancer at a young age.

TP53 is a tumor suppressor whose inherited loss-of-function mutations cause Li-Fraumeni syndrome, a hereditary condition marked by early-onset cancer. This frameshift is predicted to eliminate p53 function through nonsense-mediated decay, and it is absent from large population databases. The Likely Pathogenic classification therefore points to a probable loss-of-function mutation with clinical implications for cancer-risk surveillance.