TP53Variant Clusters Stratify the Li-Fraumeni Spectrum and Reveal an Osteosarcoma-Prone Subgroup

Abstract

ABSTRACTLi-Fraumeni syndrome (LFS) has recently been redefined as a ‘spectrum’ cancer predisposition disorder to reflect its broad phenotypic heterogeneity. The wide functional gradient associated with differentTP53variants is thought to contribute to LFS heterogeneity, although it is still poorly understood and there is an unmet clinical need for risk stratification strategies. Leveraging p53 mutagenesis dataset, we performed an unsupervised cluster analysis that revealed fiveTP53variant clusters with unique structural and functional consequences. Classifying variant carriers according to these clusters stratified cancer onset and survival using discovery and validation cohorts, and exposed important clinical characteristics to consider for patient management. In particular, we identified a subgroup of monomericTP53variant carriers prone to osteosarcoma, along with a cluster associated with less “LFS-like” phenotypes enriched in carriers with no history of cancer. Our classification ofTP53variants demonstrates the existence of a wideTP53-heritable cancer susceptibility spectrum and provides a new framework to delineate carriers toward personalized patient care.