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 loss of function causes Li-Fraumeni syndrome, a hereditary condition of markedly elevated, early-onset cancer risk. This frameshift is predicted to abolish p53 function through nonsense-mediated decay, matching the gene's established loss-of-function disease mechanism, and the likely pathogenic result supports clinical surveillance for variant carriers.