Genotype-phenotype correlations among TP53 carriers: Literature review and analysis of probands undergoing multi-gene...

Pathogenic germline variants in the TP53 gene predispose to a wide range of cancers, known collectively as Li-Fraumeni syndrome (LFS). There has been much research aimed to identify genotype-phenotype correlations, that is, differences between variant location and/or effect and cancer spectrum. These correlations, should they exist, have potential to impact clinical management of carriers. Review of previously published studies showed a variety of study designs and inconsistency in reported findings. Here, we used pooled data from 427 TP53 carriers who had undergone multigene panel testing and 154 TP53 carriers identified by single-gene testing to investigate correlations between TP53 genotype (truncating variants, hotspot variants, other missense variants with dominant-negative effect, missense variants without dominant-negative effect) and a number of LFS-selected malignancies. Our results suggest that carriers of truncating and hotspot variants might be more likely to present with LFS cancers and have shorter time to first cancer diagnosis compared to carriers of other variant types. However, the differences observed were minor, and we conclude that there is currently insufficient evidence to consider location and/or molecular effect of pathogenic variants to assist with clinical management of TP53 carriers. Larger studies are necessary to confirm the correlations suggested by our analysis.