TP53 and Li-Fraumeni syndrome: Consistent with this are mutation detection rates of ∼4% in individuals with earlier-onset (≤30 years) breast cancer36 and ∼17% in MPT-affected individuals who were referred for germline TP53 testing and who generally fulfilled criteria for that investigation, had tumors characteristic of Li Fraumeni syndrome, and had an average age at diagnosis (of a first primary tumor) before 30 years.2